﻿ticket,summary,version,created,modified,_changetime,_description,_reporter
21447,VirtualBox 7.x + | DNS / Name resolution problem,VirtualBox-7.0.6,2023-01-30T14:20:10Z,2023-01-31T13:57:24Z,2023-01-31T13:57:24Z,"When trying to install a VM with Linux as guest OS under VirtualBox 7.x, the installation fails at the name resolution of the online repo.
This was tested with Debian and Arch Linux. 
The installation gives an error at the moment when the name resolution to the repo is needed.
To exclude an error in the images, Debian was installed from a full image, for this no online repo is necessary during the installation.
In the freshly started OS, however, the error of the non-existent name resolution occurs again, SSH via port forwarding does not work either.
A ping to ""google.de"" is unsuccessful. 
A ping to ""8.8.8.8"", is successful.
During the installation all default values of the installer were taken over.

'''When performing the same installations on VirtualBox 6.1.42, this error does not occur and the name resolution works, likewise SSH works without problems.'''

'''Host: Windows 10 Pro 22H2'''

'''Guest: Debian Stable Bullseye 11.6.0 (Kernel 5.10)
Arch Linux Rolling (Kernel 6.1)'''",carcap
21062,BUG in updating Nat Network configuration: parameter Network CIDR,VirtualBox 6.1.36,2022-08-14T19:28:06Z,2022-08-14T19:28:06Z,2022-08-14T19:28:06Z,"Changing the parameter Network CIDR does not affect the correct configuration of the DHCP server active on the NAT network.
The IP address of the DHCP server and the range of addresses served are not updated.

For the walkthrough see my post on Forum

https://forums.virtualbox.org/viewtopic.php?f=7&t=106799 ",sagypt
21006,DHCP provides wrong DNS server address if DNS server address is not requested,VirtualBox 6.1.34,2022-06-23T13:15:35Z,2022-06-23T13:15:35Z,2022-06-23T13:15:35Z,"VirtualBox 6.1 on Fedora Linux with NAT networking:

If the DHCP client in the VM does not provide option 55 -  Parameter Request List - or does provide one, but does not provide Item 6 - Domain Name Sever - in DCHDISCOVER, then the VirtualBox builtin DHCP server will respond with a DHCPOFFER containing a DNS Sever option, anyway.

But the address specified in this option will be invalid. More specifically, instead of providing 10.0.2.3, it will provide whatever is in /etc/hosts. This may go unnoticed if the DNS sever listed in /etc/hosts has a routable address.

On a Fedora Linux the DNS server in /etc/hosts has the address 127.0.0.53, which is not routable and as such when the VM tries to talk to it, it fails (it has no such local address configured).

Interestingly, if I manually configure the DNS server address in the guest OS to 10.0.2.3, the VirtualBox DNS server does not respond on that address.

I can reproduce this on HelenOS as of Git revision 52214a2d97559c2396ecbcd3de80863dab438fb3. Unfortunately this cannot be tested with a binary release (e.g. the latest, HelenOS 0.11.2) as it misses a fix for another problem that HelenOS DHCP has in VirtualBox.
",JiriS
20715,"VirtualBox 6.1.30: ""vboxmanage natnetwork"" lacks of options to set IPv6 prefix and enable/disable router advertisements",VirtualBox 6.1.30,2021-12-03T18:14:14Z,2021-12-03T18:14:14Z,2021-12-03T18:14:14Z,"VirtualBox 6.1.30: ""vboxmanage natnetwork"" lacks of options to set IPv6 prefix and enable/disable router advertisements.

Example:
vboxmanage natnetwork add --netname ISP-Alpha \
   --network 172.31.255.0/24 \
   --enable \
   --dhcp no \
   --ipv6 yes

""--network"" only allows to configure the IPv4 network. There is no corresponding option for IPv6. It is only possible to turn IPv6 on/off, and the prefix gets configured automatically. Documentation about how the IPv6 prefix is computed is missing! (And there is a bug in this automatic configuration as well: https://www.virtualbox.org/ticket/20714)

DHCP can be enabled with ""--dhcp"", but there is no option to turn on ICMPv6 router advertisements and/or DHCPv6.",Thomas Dreibholz
20589,"NAT TFTP: leading slash in path cause ""Access violation""",VirtualBox 6.1.26,2021-10-01T18:22:50Z,2021-10-05T20:34:25Z,2021-10-05T20:34:25Z,"I was trying to boot Grub2 using the built-in NAT TFTP. However, after being successfully loaded by iPXE Grub fails to load the additional files (/boot/grub/i386-pc/normal.mod, etc.) printing: error: Access violation

Same error is returned by NAT TFTP when using a tftp client on a booted Gust OS when the requested path has a leading forward slash.

Workaround: switch to an alternative TFTP server on localhost:
{{{
VBoxManage modifyvm SLESInst --nattftpserver1 10.0.2.2
}}}
Steps to reproduce:

- Generate Grub dir without grub.cfg or vmlinuz/initrd (they're not needed for testing)
{{{
[root@reallin il]# grub-mknetdir --net-directory=/srv/tftp --subdir=/boot/grub -d /usr/lib/grub/i386-pc
Netboot directory for i386-pc created. Configure your DHCP server to point to /srv/tftp/boot/grub/i386-pc/core.0
}}}
- Copy the files to the default TFTPPrefix
{{{
cp -rT /srv/tftp/boot ~/.VirtualBox/TFTP/boot
}}}
- point the VBox DHCP server to the right file
{{{
# If I use leading slash here boot fails sooner
VBoxManage modifyvm MyVM --nattftpfile1=boot/grub/i386-pc/core.0
}}}
- Boot a guest from Network

Expected: Grub loads in ""Normal"" mode

Actual: Grub loads in ""Rescue"" mode.

Additional info:
{{{
[il@reallin ~]$ atftp 10.0.2.4
tftp> get boot/grub/i386-pc/core.0
Overwrite local file [y/n]? y
tftp> get /boot/grub/i386-pc/core.0
Overwrite local file [y/n]? y
tftp: error received from server <Access violation>
tftp: aborting
tftp> 
}}} 
",lfmeloman
20419,NAT Port Forwarding CONN RESET ISSUES,VirtualBox 6.1.22,2021-06-16T17:42:24Z,2021-06-19T04:56:49Z,2021-06-19T04:56:49Z,"Trying to port forward port 10000-10002 between the 
windows 10 pro host OS
windows 10 enterprise guest OS

on those ports the guest contains the microsoft azure storage emulator endpoints.

I am trying to make REST API call to those endpoints from the host OS will no sucess.

So far, I have turned off the windows defender firewall in the Guest OS  and allowed for the TCP,UDP inbound outbound connections on the HOST OS. I also upgraded my VM FROM 6.1.18-142142 TO 6.1.22-144080.This happend for browser, web app API, python and C#. We know this is the case becuase the API call to MySQL on guest 3306 works sucesfully and on turning off the guest OS, the failed call indicated the MySQL server was only on the guest

The results were from a HTTP Requests that hangs to a requests that respond ""CONNECTION RESET"", this happend on both versions of virtual box
",windmillcode
20337,Natnetwork loose connectivity after a while,VirtualBox 6.1.22,2021-05-04T08:29:04Z,2021-05-04T08:29:04Z,2021-05-04T08:29:04Z,"Hi,
I have created 5 VMs based on Debian 10, with Natnetwork configured (because i need to let the VMs talk to each others and access the Vpn on the host).

Each one has static IP, no specific tunning or special configuration. just Debian Vms and default natnetwork configured.

All Vms are working without any problems, i can access it with port forwarding. and after a while (one minute, 3 minutes...), the IP connectivity is suddenly cut, the ssh connections are stuck !

I must restart the natnetwork with VBoxManage ... Same result with paravirtualized network interface or Intel Pro desktop.
So, it s impossible to work in theses conditions.

it seems that problem exists for years or i missed something ?

Thanks to do something on that issue.
Francois




",Francois94130
20302,Client ID prevails over MAC based mapping with the NAT Network DHCP server,VirtualBox 6.1.18,2021-04-13T09:35:05Z,2021-04-22T14:00:30Z,2021-04-22T14:00:30Z,"I've got two Ubuntu (though what matters here is Systemd-Network) guest VMs connected to a NAT Service network with the DHCP service enabled.
I have added a static mapping between the guests NIC MAC addresses and their assigned IPs. The NatNetwork-Dhcpd.config file shows what I mean:

    <Config MACAddress=""08:00:27:00:00:01"" name=""59c98231-ac44-4e62-8bfe-1bd937c3fff1/0"" fixedAddress=""192.168.40.101""/>

    <Config MACAddress=""08:00:27:00:00:02"" name=""824e3a1b-2542-454d-bfee-c8aad2ad1c90/0"" fixedAddress=""192.168.40.102""/>

The same information is reflected in `VirtualBox.xml` (the global config file) though when using `VBoxManage` to set up the mapping I did use the first NIC of each guest to set the mapping hence the `/0` after the guest VM UUID:


    <Config MACAddress=""08:00:27:00:00:01"" name=""59c98231-ac44-4e62-8bfe-1bd937c3fff1/0"" fixedAddress=""192.168.40.101""/>

    <Config MACAddress=""08:00:27:00:00:02"" name=""824e3a1b-2542-454d-bfee-c8aad2ad1c90/0"" fixedAddress=""192.168.40.102""/>

Now it comes the twist: DHCP Client ID in machines running Systemd-Network use /etc/machine-id to construct it but both machines have the same contents (due to cloning, you know) in this file hence the Client ID sent to the DHCP is always the same (as seen in NatService-Dhcpd.log)... and the dhcp server in the Nat Service returns the same IP address for both guests.

Is it a bug, a feature or just RFC compliance?
Thanks in advance.",jcb
20283,Network issues on Guest-VM,VirtualBox 6.1.18,2021-04-02T19:41:36Z,2021-04-24T18:56:04Z,2021-04-24T18:56:04Z,"Hey,

I am using VirtualBox on macOS Big Sur and seem to have found a problem.
I am running a Linux VM with a NAT-Network or NAT adapter and whenever I run nmap on there I am unable to reach my gateway (host) anymore. 
It's either non-responsive or responding very slowly (700ms-3000ms).

[img]https://imgur.com/a/2HU4Lrk[/img]

Is there any fix for this?",Eagleo0
20279,Long-timeout TCP Sessions,VirtualBox 6.1.18,2021-03-28T20:53:11Z,2021-03-28T20:53:11Z,2021-03-28T20:53:11Z,"I have a case with long time-out TCP sessions that come from VirtualBox NAT network mode. When I created half-open TCP sessions from the VM to an external TCP Host (by sending SYN packets but not reply the SYN/ACK with ACK packets). After 10 seconds, the external TCP Host proceeded to close the connections by sending FIN packets. This put the port VirtualBox used for those connections to CLOSE_WAIT state. As I observed, the current VirtualBox's CLOSE_WAIT timeout is about 10 minutes.

I have a theory that, if I can generate enough number (maybe 40,000?) of CLOSE_WAIT state TCP sessions, I can occupy all of the port VirtualBox can use for transmitting, which make the internal VM can not create new connection with external hosts, for 10 minutes. 

I suggest that the CLOSE_WAIT timeout should be lowered to 2 minutes to counter the possible problem.",nds21
19837,Forwarded ports are blocked,VirtualBox 6.1.10,2020-08-27T13:42:17Z,2020-08-27T13:42:17Z,2020-08-27T13:42:17Z,"It can happen that ports which are forwarded to the guest are blocked on the host and therefore you are unable to open those ports on the host. Then you have to remove the forwarding, open the ports and then re-add the forwarding.

Expected behaviour:
Forwarded ports should not be blocked.",jnevada
19675,DHCP server mac address conflicts with nat-host mac-address,VirtualBox 6.1.10,2020-06-19T19:56:40Z,2020-06-19T19:56:40Z,2020-06-19T19:56:40Z,"
https://gitlab.alpinelinux.org/alpine/aports/-/issues/11669

When the two mac-addresses of the dhcp server and the emulated-host interface in NatNetwork are different, the arp cache may end up with the mac address of host entered as that from the dhcp. WHen that happens further communcation with host (CIFS/ssh) fails.

The eesolution was to set the dhcp server from the default 10.1.x.2 to 10.1.x.5. Then mac addresses don't clash

There should be a vboxmanage setting to set the mac address of the 
host-ip and of the dhcp-server-ip ",gkamathh
19651,DNS not working with NAT on some networks.,VirtualBox 6.1.10,2020-06-09T12:39:59Z,2020-06-09T12:39:59Z,2020-06-09T12:39:59Z,"Host is Win10, Guest is Debian 10.  Network set to NAT with TCP port 22 forwarded (though ssh will not work either)

Internet access worked fine until I changed WIFI networks. DNS does not seem to work. I can ping the DNS server, but DNS resolving does not work.  I've noticed some strange patterns.  At home it works fine. When I connect to my cellphone hotspot while at home everything worked too. At my hotel, at first it would not work. Then trying at my remote office guest wifi network, it also would not work. Then trying my cellphone hotspot mode, it also would not work. However, upon returning back to my hotel, it suddenly worked. I have the exact same pattern with trying to connect my wireguard vpn. Note back at the hotel, once I connect the vpn, dns stops working, it is unable to contact the dns server on my vpn, eventhough the host is able to.  Virtualbox sees the network changes, debian updates the network configuration, I can ping addresses outside, but dns fails with the ICMP issue. I've noticed that the DNS issue is ok if I switch to a bridged network. Unfortunately, some networks will only give me one IP so getting it to work with NAT is preferred.


In the VM log, I see:
{{{
00:00:18.130180 NAT: Link up
00:00:19.424766 NAT: DHCP offered IP address 10.0.2.15
}}}
On the guest, in network manager, it has a 10.0.2.15 IP address and is able to get DNS servers matching what I have on the host. /etc/resolv.conf has the correct servers
I have tried rebooting the VM. I've tried turning off the firewall on the host.


/etc/resolv.conf:
{{{
nameserver 1.1.1.1
}}}
ping 1.1.1.1 works
{{{
11:38:39.397764 IP 10.0.2.15 > 1.1.1.1: ICMP echo request, id 2960, seq 2, length 64
11:38:39.436573 IP 1.1.1.1 > 10.0.2.15: ICMP echo reply, id 2960, seq 2, length 64
}}}
dig @1.1.1.1 google.com does not work
{{{
11:38:43.814134 IP 10.0.2.15.50821 > 1.1.1.1.53: 29800+ [1au] A? google.com. (51)
11:38:43.814861 IP 10.0.2.2 > 10.0.2.15: ICMP net 1.1.1.1 unreachable, length 36
11:38:45.697058 IP 10.0.2.15.50263 > 172.30.0.27.53: 32978+ AAAA? clients3.google.com. (37)
11:38:45.697650 IP 10.0.2.15.46410 > 172.30.0.27.53: 56459+ A? clients3.google.com. (37)
11:38:45.698116 IP 10.0.2.2 > 10.0.2.15: ICMP net 172.30.0.27 unreachable, length 36
11:38:45.698446 IP 10.0.2.2 > 10.0.2.15: ICMP net 172.30.0.27 unreachable, length 36
11:38:48.814785 IP 10.0.2.15.50821 > 1.1.1.1.53: 29800+ [1au] A? google.com. (51)
11:38:48.816463 IP 10.0.2.2 > 10.0.2.15: ICMP net 1.1.1.1 unreachable, length 36
}}}",eng3
19552,NAT Network is not working when I try to create or edit  a different IP other than (10.0.2.0)),VirtualBox 6.1.6,2020-05-04T09:19:43Z,2020-05-04T09:19:43Z,2020-05-04T09:19:43Z,"Virtualbox  version 6.1.6

This version has issues when trying to ping internet using NAT network.
there is no pin and cannot access the internet.

the problem is not in the default NAT network created by virtualbox 10.0.2.0/24.

the problem appears when i configure a new NAT network or edit the default one, like for example 192.168.0.0/24 in this case it will not work and can not access the internet.

I tested the following versions 6.0.20, 6.0.18, 6.0.12 and all of them work fine with no problems. 

 ",hassanmonji
19536,"Problems when switching from ""NAT"" to ""Bridge"" and vice versa. VM is not assigned an IP address via DHCP when using ""Bridge"".",VirtualBox 5.2.40,2020-04-26T14:19:17Z,2020-04-26T14:19:17Z,2020-04-26T14:19:17Z,"Host is a Windows 10 (Build 1909). If you change in Virtualbox 5.2.40 with a VM (Windows 10 (Build 1909) in the network area from ""NAT"" to ""Bridge"" the VM does not get a new IP address via DHCP within the VM. 
With Virtualbox 5.2.38 it works with the same host and with the same VMs without problems online. You can switch between ""NAT"" and ""Bridge"" and the VM gets an IP address internally via its DHCP service. This can also be observed in the DHCP server of the network.  

The error is reproducible and occurs immediately after installing Virtualbox 5.2.40 and disappears as soon as Virtualbox 5.2.38 is installed again.",RonaldMcDonald
19478,NAT limitations,VirtualBox 6.1.4,2020-04-11T19:07:24Z,2020-04-11T19:11:12Z,2020-04-11T19:11:12Z,"Current version NAT limitations are well documented in https://www.virtualbox.org/manual/UserManual.html#nat-limitations

Some of them, such as ICMP, have been there over ten years, as this bugtrack documents: https://www.virtualbox.org/ticket/181

So, back in march 2007, ""Frank"" decided that is was ""wontfix"".

I am trying to use VoIP solutions (SIP), asterisk, etc but I would prefer to use a VM box and use NAT for this. I am experiencing dificulties that I believe are due to those sw using inside ICMP, so, no ICMP no working...

TIA",caspertone2003
19308,"Networking mode ""NAT Network"" shows very poor throughput",VirtualBox 6.0.16,2020-02-13T12:47:40Z,2020-02-13T12:47:40Z,2020-02-13T12:47:40Z,"Information about my environment:

Physical Host: Windows 10
VBox version: 6.0.16

Guest VM: Debian 9 Linux, 64 bit
Guest additions: 6.0.16.
Networking mode: NAT Network



Use case and problem description: 
I have a Linux guest on Win10 host, using vbox 6.0.16 guest additions. The VM rsync files from a vboxsf shared folder to a remote host via SSH. The network is 
plenty fast (modern 802.11n network - not used for anything else) on which I can easily achieve > 50 MiB/s (measured by iperf) from the host to the remote 
server. However, when I go from guest to remote server, it maxes out at about 200kiB/s

I have checked via atop and htop that CPU is not a bottleneck on neither client nor server. And the physical network is obviously not the bottleneck...
I have verified that I can both read and write files from the vboxsf share plenty fast as well.



I just tried plain NAT as networking mode and that works MUCH better. Now it is several MiBs per second. So it must be something to do with NAT network


So I guess there must be a problem in how networking is implemented in NAT Network compared to plain NAT that causes the slowdown.

",tdn
19128,Kernel bug (vboxdr - VBoxNetFlt) - eth device unintentionally enters promiscuous mode,VirtualBox 6.0.14,2019-12-03T21:42:59Z,2019-12-04T06:44:26Z,2019-12-04T06:44:26Z,"Hello, 

When a natnetwork definied. For a while, after some reboots of VM, when VM just started Linux Kernel shows problems.
It is reproducabe: make a new natnetwork eg. like this:

{{{

$ VBoxManage natnetwork add --netname anyad \
--network ""192.168.15.0/24"" --enable --ipv6 on \
--port-forward-4 ""www:tcp:[]:10080:[192.168.15.10]:80"" \
--port-forward-4 ""ssh:tcp:[]:10022:[192.168.15.10]:22"" \
--port-forward-4 ""ssl:tcp:[]:10443:[192.168.15.10]:443"" \
--port-forward-6 ""www_ipv6:tcp:[]:10080:[192.168.15.10]:80"" \
--port-forward-6 ""ssh_ipv6:tcp:[]:10022:[192.168.15.10]:22"" \
--port-forward-6 ""ssl_ipv6:tcp:[]:10443:[192.168.15.10]:443
}}}
""


{{{
$ VBoxManage dhcpserver modify --ip 192.168.15.3 --netmask 255.255.255.0 \
--netname anyad --lowerip 192.168.15.10 --upperip 192.168.15.100
}}}


Then you select natnetwork definied above for VM. After some rebootings of VM there will be Kernel messages just when you start the affected VM like this:


{{{
[ 6693.723692] vboxdrv: 0000000000000000 VMMR0.r0
[ 6693.850079] vboxdrv: 0000000000000000 VBoxDDR0.r0
[ 6693.896097] VBoxNetFlt: attached to 'enp3s0' / xx:zz:xx:zz:xx:zz
[ 6693.901656] vboxdrv: 0000000000000000 VBoxEhciR0.r0
}}}

No need VM to start the guest OS totally, as soon as VM begun to run the Kernel messages sign.
When VM will be just stopped, Kernel message will be like this:
{{{

[ 6355.406993] device enp3s0 left promiscuous mode
[ 6356.691870] vboxnetflt: 0 out of 9668 packets were not sent (directed to host)

}}}

Temporary workaround:

{{{
$ VBoxManage natnetwork remove --netname anyad
$ VBoxManage dhcpserver remove --netname anyad
}}}

After re-make a new natnetwork with same option like above I wrote.


Affected VB versions: 6.0.14 and 6.1.0_RC1 r135151[[BR]]

Affected Kernel: Linux 5.0.0-36-generic",petervagyok
18932,No DNS from DHCP on NAT connection,VirtualBox 6.0.12,2019-09-16T13:48:19Z,2019-09-17T00:05:17Z,2019-09-17T00:05:17Z,"On VirtualBox 6.0.12, with plain NAT configuration, the domain name resolution does not work anymore on Windows/Linux guests on Windows host.

I've checked quite everything on host and guests configuration and come up to the hypothesis that VirtualBox dhcp ""server"" does not send the DNS address, but it used to do on previous versions.

This is confirmed by DHCP not containing the DNS entry as shown by the following DHCP response:


{{{
$ sudo nmap --script broadcast-dhcp-discover

Starting Nmap 7.60 at 2019-09-12 08:08 CEST
Pre-scan script results:
| broadcast-dhcp-discover:
|   Response 1 of 1:
|     IP Offered: 10.0.2.16
|     DHCP Message Type: DHCPOFFER
|     Subnet Mask: 255.255.255.0
|     Router: 10.0.2.2
|     IP Address Lease Time: 1d00h00m00s
|_    Server Identifier: 10.0.2.2
WARNING: No targets were specified, so 0 hosts scanned.
Nmap done: 0 IP addresses (0 hosts up) scanned in 0.51 seconds
}}}
",Han Fastolfe
18751,Very low upload throuput in NAT adapter - Windows 10 x64 1903 host/guest,VirtualBox 6.0.8,2019-07-11T21:52:11Z,2019-10-20T23:57:16Z,2019-10-20T23:57:16Z,"Virtualbox 6.0.8+Extensions+VBoxGuestAdditions

Upload throuput using NAT is so extremaly bad, as compared to what Bridged provides, that I wonder if a bug could be there.

Full details explained here https://forums.virtualbox.org/viewtopic.php?f=2&t=93707

As workaround I switch on/off one or the other interface in the guest.",caspertone2003
18495,VirtualBox NAT alias option use-same-ports (--nataliasmode1=sameports) has no effect on Ubuntu 16.04 host OS,VirtualBox 6.0.4,2019-03-14T20:53:00Z,2019-03-14T20:53:00Z,2019-03-14T20:53:00Z,"== Steps to reproduce ==

    1. Create a VirtualBox VM as follows, accepting default values for anything not listed here:

        * Name: archlinux-2019.03.01-x86_64
        * Type: Linux
        * Version: Arch Linux (64-bit)

    2. Download archlinux-2019.03.01-x86_64.iso into the VM directory:

    {{{
cd 'VirtualBox VMs'/archlinux-2019.03.01-x86_64
curl -O http://mirrors.acm.wpi.edu/archlinux/iso/2019.03.01/archlinux-2019.03.01-x86_64.iso
    }}}

    3. Confirm the MD5 checksum. First, display the expected checksum:

    {{{
curl http://mirrors.acm.wpi.edu/archlinux/iso/2019.03.01/md5sums.txt
    }}}

    Verify on Linux:

    {{{
md5sum archlinux-2019.03.01-x86_64.iso
    }}}

    Verify on macOS:

    {{{
md5 archlinux-2019.03.01-x86_64.iso
    }}}

    4. Start the VM in VirtualBox, click '''Choose a virtual optical disk file''' (represented by a folder icon with an upward-pointing green arrow), and select the archlinux-2019.03.01-x86_64.iso file downloaded in Step 2.

    5. Boot the VM, selecting default options for everything.

    6. On the host (64-bit Ubuntu Xenial Xerus 16.04.6 LTS), find two unused privileged (port number less than 1024) ports; for example, the following command will return nothing if both ports 1022 and 1023 are free:

    {{{
netstat -Wa | grep -E '1022|1023'
    }}}

    7. On the guest (64-bit Arch Linux 2019.03.01), confirm that the first free port from Step 6 is also free on the guest:

    {{{
netstat -Wa | grep 1022
    }}}

    If this  command returns any output, repeat Steps 6 and 7 until you have found two free ports.

    8. On the host (64-bit Ubuntu Xenial Xerus 16.04.6 LTS), start listening on the second free port, the receiving port:

    {{{
sudo nc -l 1023
    }}}

    9. On the guest (64-bit Arch Linux 2019.03.01), open a connection to the receiving port on the host, originating the connection from the first free port, the sending port:

    {{{
nc -p 1022 ala-michaelk-lx1.corp.ad.wrs.com 1023
    }}}

    Replace `ala-michaelk-lx1.corp.ad.wrs.com` with the fully qualified domain name (FQDN) of the host, as returned by the `hostname -f` command.

    After running both `nc` commands, any text entered on the guest should appear on the host and vice versa.

    10. In another shell on host, look for connections to the receiving port:

    {{{
netstat -W | grep 1023
    }}}

    Initially observe that network address translation (NAT) has replaced the sending port (1022) with a random port (48946), as expected for `--nataliasmode1=default`:

    {{{
$ netstat -W | grep 1023
tcp        0      0 ala-michaelk-lx1.corp.ad.wrs.com:1023 ala-michaelk-lx1.corp.ad.wrs.com:48946 ESTABLISHED
tcp        0      0 ala-michaelk-lx1.corp.ad.wrs.com:48946 ala-michaelk-lx1.corp.ad.wrs.com:1023 ESTABLISHED
    }}}

    11. On the host (64-bit Ubuntu Xenial Xerus 16.04.6 LTS), close the connection by pressing Ctrl-D (EOF) in the shell running `nc`.

    12. Close the guest console window, select '''Save the machine state''', and click '''OK'''.

    13. On host, switch the VM to `--nataliasmode1=sameports`:

    {{{
VBoxManage modifyvm archlinux-2019.03.01-x86_64 --nataliasmode1=sameports
    }}}

    14. In VirtualBox, click '''Start''' to restore the VM.

    15. Repeat Steps 8–11.

== Expected ==

The port number for the sending port (1022) is preserved, as seen on host macOS Mojave Version 10.14.3:

{{{
inu:~ michael$ netstat -W | grep 1023
tcp4       0      0  inu.corp.ad.wrs.com.1023  inu.corp.ad.wrs.com.1022  ESTABLISHED
tcp4       0      0  inu.corp.ad.wrs.com.exp2  inu.corp.ad.wrs.com.1023  ESTABLISHED
}}}

== Observed ==

The port number for the sending port (1022) is replaced with a random port number, as seen on host 64-bit Ubuntu Xenial Xerus 16.04.6 LTS:

{{{
$ netstat -W | grep 1023
tcp        0      0 ala-michaelk-lx1.corp.ad.wrs.com:48972 ala-michaelk-lx1.corp.ad.wrs.com:1023 ESTABLISHED
tcp        0      0 ala-michaelk-lx1.corp.ad.wrs.com:1023 ala-michaelk-lx1.corp.ad.wrs.com:48972 ESTABLISHED
}}}
",interfrastic
18178,NAT driver drops inbound retransmits that happen after FIN,VirtualBox 5.2.22,2018-12-12T03:11:43Z,2018-12-12T14:54:15Z,2018-12-12T14:54:15Z,"In TCP, it is possible and allowed (and actually, necessary) for the sending side to retransmit after sending the FIN but before receiving a FIN from the other side.  The sending side will send a final ""window"" of TCP segments, ending with a FIN packet.  If one of those is dropped, the receiving side should ACK the most recently received packet, then the sender will retransmit.  Only after all packets are received and acknowledged should the recipient ACK the sender's FIN segment and send back its own.

Instead, guests within virtualbox seem to immediately respond to the FIN with a FIN/ACK and tear down the connection.  This means that if a segment is dropped within the final window transmission, the download is silently truncated.  It's likely a rare bug, in that it only becomes high-probability with a combination of high latency, large window sizes, and nontrivial amounts of packet loss.  With almost all TCP schedule algorithms, even small amounts of packet loss result in a very small transmission window.  The new BBR, on the other hand, tries to probe the latency and bandwidth available rather than relying on packet loss for feedback, so it's far more likely to result in a large TCP window despite some packet loss.",Elliott
18100,Old DHCP leases interfere with changed server configuration,VirtualBox 5.2.20,2018-11-03T19:31:54Z,2018-11-03T19:35:58Z,2018-11-03T19:35:58Z,"Host: openSUSE Leap 15

virtualbox-host-kmp-default-5.2.20_k4.12.14_lp150.12.22-lp150.4.20.1.x86_64
virtualbox-host-source-5.2.20-lp150.4.20.1.noarch
virtualbox-5.2.20-lp150.4.20.1.x86_64
virtualbox-qt-5.2.20-lp150.4.20.1.x86_64

In short, the lease file for a NAT net must be deleted by hand. Otherwise the DHCP server (with a different IP) hands out the old leases (wrong IPs).",robert spitzenpfeil
18068,NAT process infinite loop call `poll` function,VirtualBox 5.2.20,2018-10-22T07:42:56Z,2018-10-22T07:42:56Z,2018-10-22T07:42:56Z,"Host machine: Fedora 28
Guest machine: Windows 10

My guest system is Windows 10 and using NAT network, and Windows 10 system suddenly unable to access the Internet at some point, but my host machine can access the network normally. I using Wireshark capturing some ARP data flow in Windows 10:

{{{
1   0.000000 PcsCompu_7a:1a:df → RealtekU_12:35:02 ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
    2   0.207297 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
    3   3.718693 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
    4   4.500012 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
    5   5.500048 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
    6   6.719889 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
    7  10.721331 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
    8  11.499537 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
    9  12.500007 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   10  15.499582 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   11  16.721794 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   12  17.500389 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   13  18.500008 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   14  21.499517 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   15  22.725696 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   16  23.499997 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   17  24.499501 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   18  27.499508 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   19  27.982749 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   20  28.500004 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   21  29.500001 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   22  34.985277 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   23  35.500502 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   24  36.500023 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   25  38.248133 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   26  42.249642 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   27  42.999528 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   28  43.999519 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   29  47.235338 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   30  48.000015 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
   31  49.000018 PcsCompu_7a:1a:df → Broadcast    ARP 42 Who has 10.0.2.2? Tell 10.0.2.15
}}}

IP 10.0.2.2 is NAT's gateway address, as you see, my Windows system send some ARP broadcast packet to find 10.0.2.2's MAC address, but not recive any response packet.

At the same time, in my host machine, the `NAT` process occupies a lot of CPU resources. I using `strace` command tracing `NAT` process:

{{{
poll([{fd=46, events=POLLPRI|POLLRDNORM|POLLRDBAND}, {fd=45, events=POLLIN}, {fd=98, events=POLLIN|POLLPRI}, {fd=76, events=POLLIN|POLLPRI}, {fd=229, events=POLLIN|POLLPRI}, {fd=93, events=POLLIN|POLLPRI}, {fd=91, events=POLLIN}, {fd=89, events=POLLIN}, {fd=81, events=POLLIN}, {fd=96, events=POLLIN}, {fd=102, events=POLLIN}, {fd=97, events=POLLIN}, {fd=88, events=POLLIN}, {fd=70, events=POLLIN}, {fd=68, events=POLLIN}], 15, 500) = 1 ([{fd=91, revents=POLLIN}])
poll([{fd=46, events=POLLPRI|POLLRDNORM|POLLRDBAND}, {fd=45, events=POLLIN}, {fd=98, events=POLLIN|POLLPRI}, {fd=76, events=POLLIN|POLLPRI}, {fd=229, events=POLLIN|POLLPRI}, {fd=93, events=POLLIN|POLLPRI}, {fd=91, events=POLLIN}, {fd=89, events=POLLIN}, {fd=81, events=POLLIN}, {fd=96, events=POLLIN}, {fd=102, events=POLLIN}, {fd=97, events=POLLIN}, {fd=88, events=POLLIN}, {fd=70, events=POLLIN}, {fd=68, events=POLLIN}], 15, 500) = 1 ([{fd=91, revents=POLLIN}])
poll([{fd=46, events=POLLPRI|POLLRDNORM|POLLRDBAND}, {fd=45, events=POLLIN}, {fd=98, events=POLLIN|POLLPRI}, {fd=76, events=POLLIN|POLLPRI}, {fd=229, events=POLLIN|POLLPRI}, {fd=93, events=POLLIN|POLLPRI}, {fd=91, events=POLLIN}, {fd=89, events=POLLIN}, {fd=81, events=POLLIN}, {fd=96, events=POLLIN}, {fd=102, events=POLLIN}, {fd=97, events=POLLIN}, {fd=88, events=POLLIN}, {fd=70, events=POLLIN}, {fd=68, events=POLLIN}], 15, 500) = 1 ([{fd=91, revents=POLLIN}])
poll([{fd=46, events=POLLPRI|POLLRDNORM|POLLRDBAND}, {fd=45, events=POLLIN}, {fd=98, events=POLLIN|POLLPRI}, {fd=76, events=POLLIN|POLLPRI}, {fd=229, events=POLLIN|POLLPRI}, {fd=93, events=POLLIN|POLLPRI}, {fd=91, events=POLLIN}, {fd=89, events=POLLIN}, {fd=81, events=POLLIN}, {fd=96, events=POLLIN}, {fd=102, events=POLLIN}, {fd=97, events=POLLIN}, {fd=88, events=POLLIN}, {fd=70, events=POLLIN}, {fd=68, events=POLLIN}], 15, 500) = 1 ([{fd=91, revents=POLLIN}])
poll([{fd=46, events=POLLPRI|POLLRDNORM|POLLRDBAND}, {fd=45, events=POLLIN}, {fd=98, events=POLLIN|POLLPRI}, {fd=76, events=POLLIN|POLLPRI}, {fd=229, events=POLLIN|POLLPRI}, {fd=93, events=POLLIN|POLLPRI}, {fd=91, events=POLLIN}, {fd=89, events=POLLIN}, {fd=81, events=POLLIN}, {fd=96, events=POLLIN}, {fd=102, events=POLLIN}, {fd=97, events=POLLIN}, {fd=88, events=POLLIN}, {fd=70, events=POLLIN}, {fd=68, events=POLLIN}], 15, 500) = 1 ([{fd=91, revents=POLLIN}])
poll([{fd=46, events=POLLPRI|POLLRDNORM|POLLRDBAND}, {fd=45, events=POLLIN}, {fd=98, events=POLLIN|POLLPRI}, {fd=76, events=POLLIN|POLLPRI}, {fd=229, events=POLLIN|POLLPRI}, {fd=93, events=POLLIN|POLLPRI}, {fd=91, events=POLLIN}, {fd=89, events=POLLIN}, {fd=81, events=POLLIN}, {fd=96, events=POLLIN}, {fd=102, events=POLLIN}, {fd=97, events=POLLIN}, {fd=88, events=POLLIN}, {fd=70, events=POLLIN}, {fd=68, events=POLLIN}], 15, 500) = 1 ([{fd=91, revents=POLLIN}])
poll([{fd=46, events=POLLPRI|POLLRDNORM|POLLRDBAND}, {fd=45, events=POLLIN}, {fd=98, events=POLLIN|POLLPRI}, {fd=76, events=POLLIN|POLLPRI}, {fd=229, events=POLLIN|POLLPRI}, {fd=93, events=POLLIN|POLLPRI}, {fd=91, events=POLLIN}, {fd=89, events=POLLIN}, {fd=81, events=POLLIN}, {fd=96, events=POLLIN}, {fd=102, events=POLLIN}, {fd=97, events=POLLIN}, {fd=88, events=POLLIN}, {fd=70, events=POLLIN}, {fd=68, events=POLLIN}], 15, 500) = 1 ([{fd=91, revents=POLLIN}])
poll([{fd=46, events=POLLPRI|POLLRDNORM|POLLRDBAND}, {fd=45, events=POLLIN}, {fd=98, events=POLLIN|POLLPRI}, {fd=76, events=POLLIN|POLLPRI}, {fd=229, events=POLLIN|POLLPRI}, {fd=93, events=POLLIN|POLLPRI}, {fd=91, events=POLLIN}, {fd=89, events=POLLIN}, {fd=81, events=POLLIN}, {fd=96, events=POLLIN}, {fd=102, events=POLLIN}, {fd=97, events=POLLIN}, {fd=88, events=POLLIN}, {fd=70, events=POLLIN}, {fd=68, events=POLLIN}], 15, 500) = 1 ([{fd=91, revents=POLLIN}])
poll([{fd=46, events=POLLPRI|POLLRDNORM|POLLRDBAND}, {fd=45, events=POLLIN}, {fd=98, events=POLLIN|POLLPRI}, {fd=76, events=POLLIN|POLLPRI}, {fd=229, events=POLLIN|POLLPRI}, {fd=93, events=POLLIN|POLLPRI}, {fd=91, events=POLLIN}, {fd=89, events=POLLIN}, {fd=81, events=POLLIN}, {fd=96, events=POLLIN}, {fd=102, events=POLLIN}, {fd=97, events=POLLIN}, {fd=88, events=POLLIN}, {fd=70, events=POLLIN}, {fd=68, events=POLLIN}], 15, 500) = 1 ([{fd=91, revents=POLLIN}])
.......

}}}

as you see, NAT process infinite loop call `poll` function",lu4nx
18029,NAT network UDP port forwarding not working,VirtualBox 5.2.18,2018-10-04T07:07:04Z,2018-11-23T11:25:11Z,2018-11-23T11:25:11Z,"I've created a machine with linux ubuntu with NAT network attached.
The machine connects properly and receives an address 10.0.2.7.
I've created a port forwarding from UDP 500 to 10.0.2.7 UDP 500.
It seems that packets sent to UDP 127.0.0.1:500 are not arriving to the machine. (checked with tcpdump -i enp0s3 udp 500 on the machine.
Doing the exact same with TCP works fine.
Packets are sent with ""Packet Sender"", and verified with rawcap on the host.",Asi Lev
18020,"first packet for ping for static IP is always ""Destination host unreachable"" when you re-start your system",VirtualBox 5.2.18,2018-09-27T20:19:34Z,2018-10-01T23:16:53Z,2018-10-01T23:16:53Z,"first packet for ping for static IP is always ""Destination host unreachable"" when you re-start your windows 10 machine

Scenario to reproduce the issue.

1. reboot the laptop/system
2. try to ping any static IP 192.168..
3. you will see ""destination host unreachable"" for the 1st packet
4. result:""destination host unreachable"" for first ICMP packet 

Manual solution:
1. reboot the machine
2. go to control panel/network and sharing center
3. then go to change adapter settings
4. disable ""virtualBox Host-Only Network""
5. enable  ""virtualBox Host-Only Network""
6. Now ping any static IP
7. results: No error. Works great


",raza
17525,Conflict between VESA VBE 2.0 graphic adapter and NAT network on WINDOWS ME,VirtualBox 5.2.6,2018-02-05T03:55:19Z,2018-02-05T03:55:19Z,2018-02-05T03:55:19Z,"When you install VESA VBE 2.0 Oracle VM VirtualBox VBE Adapter to have 32 bits true color on WINDOWS ME MILLENIUM EDITION with a program called SciTech Display Doctor (this also works with win 98) you can't connect with the internet cause it seems that there's a conflict between the NAT network adapter and VESA VBE 2.0 cause I uninstalled SciTech Display Doctor and went back to standard 16 colors graphic adapter and I could access internet again. This doesnt happen with Win 98 I can install it and internet works, it's just with Millenium edition",tonypark77
17118,virtualbox nataliasmode proxyonly breaks local network connectivity on windows 10,VirtualBox 5.1.28,2017-09-28T18:09:31Z,2017-10-02T14:42:29Z,2017-10-02T14:42:29Z,"Hi,

I have enabled proxyonly for the nat and now for the entire local network i am unable to access the guest machine in any of the protocols. thoouh it is accessible from the internet.

Thanks,
Vipin",Vipin Jain
16902,P2P connections die quickly under certain circumstances,VirtualBox 5.1.22,2017-07-14T16:55:53Z,2017-07-15T09:03:45Z,2017-07-15T09:03:45Z,"Conditions to replicate are rather unusual so please cope with me:
- an application using P2P connectivity is let to operate for a few minutes (5 minutes should be more than enough);
- you may close the P2P application when you want to get to the next step. Wherever you close the P2P application and its active connections won't make a difference;
- pause the VM execution for a few minutes (5 minutes should be more than enough);
- when resuming VM try to repeat the first step and witness the connection failure.
TCP connections seam unaffected.
I only tested NAT network.

I reproduced this with [http://www.sopcast.com Sopcast] which is a P2P application.
- Install the latest version (4.2.0) in a Windows VM;
- Visit [http:///www.cooltvi.com cooltvi.com] in Internet Explorer and select a channel;
- Allow the ActiveX to run - this would start the live broadcast which is P2P based. 
Sopcast requires Direct3D9 for video to render. But this is not required to reproduce this issue, it can very well be reproduced with black screen.

I could reproduce with Windows xp/posready 2009, 7, 8.1 and 10 guests.
I tested with AMD PCNET Fast III, Intel PRO 1000 T-Server and MT Desktop, Paravirtualized Network.

I'll post logs if necessary. 
  
 
 
",pal1000
16851,Win 7 x64 Guest on Ubuntu 16.04 Host Freeze after ~4 Hours,VirtualBox 5.1.22,2017-06-21T18:34:27Z,2017-06-22T08:50:14Z,2017-06-22T08:50:14Z,"Have had a persistent problem for some time now (unsure when it started) whereby my Windows 7 x64 guest will completely lock up and is unresponsive.  VirtualBox console and other running non-Windows VMs do not seem to be affected.  The VirtualBox interface is still active and I can manipulate settings via the menu options in the GUI, but the guest OS GUI is frozen at the point it stopped working.

Saving State, then Restoring doesn't affect the outcome - only way to recover is to power off the guest VM and start it up again.

Reported this issue over in the forum (https://forums.virtualbox.org/viewtopic.php?f=7&t=82819) and was advised that this may be a rarely reproducible issue involving the NAT network subsystem and that logging a bugtrac ticket would be the best way to address this issue.

This appears to be the point at which the guest crashes (from Vbox.log):

{{{
00:26:21.080234 NAT: resolv.conf: nameserver 192.168.56.50
00:26:21.080254 NAT: resolv.conf: nameserver 127.0.1.1
00:26:21.080262 NAT: Adding domain name laptop
00:26:21.080264 NAT: DNS#0: 192.168.56.50
00:26:21.080266 NAT: DNS#1: 127.0.1.1
00:26:21.080269 NAT: DHCP offered IP address 10.0.2.15
00:26:22.688094 NAT: dnsproxy: timeout: req 00007f56d4071640 dnsgen 2 != 3 on socket 50 (udp) exp. in -427 state=SS_ISFCONNECTED f_(addr:port)=10.0.2.3:53 l_(addr:port)=10.0.2.15:50425 name=0.0.0.0:54045
03:01:30.079058 NAT: Can't allocate mbuf
03:01:38.957814 NAT: Link up
03:01:44.952776 NAT: Link up
03:01:50.966947 NAT: Link up
03:01:56.962828 NAT: Link up
03:02:02.966836 NAT: Link up
03:02:23.001524 NAT: Link up
03:02:29.001906 NAT: Link up
03:02:32.603387 VMMDev: vmmDevHeartbeatFlatlinedTimer: Guest seems to be unresponsive. Last heartbeat received 4 seconds ago
}}}


Full vbox.log file attached.
Core dump is available, but may contain sensitive data so I'd prefer not to attach to this ticket.  Have an email out to Frank Mehnert, but would gladly take instruction from elsewhere on how to get this to interested parties, securely.",John Mackoy
16789,VM dropped from network because of DHCP problems,VirtualBox 5.1.22,2017-05-26T20:42:05Z,2017-06-13T15:41:09Z,2017-06-13T15:41:09Z,"I have a VM in the NAT mode. It happened only once last month, but suddenly guest network lost its internet connection. So the card and network was here, but it has this standard 169 IP address and because of this no access to internet. Only the shutdown and start of the guest helped here. As one can see from the log, it looks like VM suddenly got some problems with DHCP in my local network, where my router is a DHCP server, and lost his 10.x.x.x address. Therefore, it got an 169.x.x.x address. Both guest and host are latest Windows 10.",boxer01
16695,VBoxNetNAT refuses connections for port-forwarding after one day or two,VirtualBox 5.1.20,2017-04-25T09:28:42Z,2017-04-25T12:17:09Z,2017-04-25T12:17:09Z,"I started using NAT network since several months ago.  My setup is quite simple: Linux host (CentOS 7.3) running two Windows 7 guests.  All guests use NAT network with static IPs.  Port-forwarding is configured on the NAT network.


{{{
NAT network: 10.0.2.1/24
Guest 1 IP: 10.0.2.11
Guest 2 IP: 10.0.2.12
Forward 1: <host_ip>:5911 <--> 10.0.0.11:5900
Forward 2: <host_ip>:5912 <--> 10.0.0.12:5900
}}}


Everything work great, until, after some time, maybe one day or two, connections to host port 2211/2212 got rejected.  One solution I find is to restart guest OS, sometime more than once, until the port-forward is normal again.

During the whole process (good --> bad --> restart --> good again), I can see that port 2211/2212 are always bound by process /usr/lib/virtualbox/VBoxNetNAT, and its pid never changed.

When connections are rejected on port 5911 and 5912, guests can connect to each other's 5900 port, which rules out guests failures.

Another observation is, sometimes the restart of one guest OS can solve problems for all guests.
",Steve Sun
16605,Network dropouts in guest since Windows 10 update to 1607 version,VirtualBox 5.1.18,2017-03-24T15:38:35Z,2017-03-31T10:07:18Z,2017-03-31T10:07:18Z,"I got here following situation. I have a Windows 10 x64 guest on the same OS host. Right now I reduced the amount of installed programs in the guest to the minimum to find the culprit. So right now there is an antivirus (latest Nod32), Firefox and MP3 Player (Xmplay) beside the OS itself. I use the last program for Internet radio since XP days, and there were no problem until now, in and outside the VM. 

Since guest update to the 1607 I can see following behavior: after 15 or 20 minutes of the streaming player starts to buffer at 70-80 % spontaneously around once in a minute, which breaks a streaming experience. One still can listen to the radio, but this is a little bit annoying. This problem only occurs if the Firefox also running in the guest. Something, I don’t know what, but probably some advertisement or data refresh, loads a little amount of the data over and over again once in nearly a minute. I got some network bandwidth pictures which explain the network flow better. But the problem isn’t a bandwidth itself – I can run a bandwidth test, which would use the whole bandwidth and still there would be no buffering. The problem is a timing, because as one can see we have something like 6 or 8 KB/s from the stream constantly, but once in a while the browser adds some 18-20 KB/s to it. So after a while there are some de-synchronization in the flow, which causes the buffering.

This only happens in the guest and only if the browser running with some sites open. If one turns the browser off, there is no buffering. Also, this can’t be reproduced running same player and stream on the host, neither with Firefox also opened on the host with some sites in it, or with Firefox running in the guest, causing the same traffic shape on the host. First of all a thought that this was a new issue with a new VB version, but I tested this with following versions (5.0.30 - 36, 5.1.6, 5.1.10, 12, 14, 16, 18) and the picture is always the same. Changing network adapter from 82540EM to paravirtualized also brings no cure. I tested it with following version of the network adapter drivers (virtio-win-0.1.110, 112, 113, 117, 118, 126, 134), but it always looks the same. There were also no such problems as I updated the host first, before the guest. The clean install of the guest OS from the scratch also doesn’t change anything in this case, but installing the previous version of Windows 10 (1511) in the guest solves the problem. I think, that the problem caused by some TCP/IP optimization in the new Windows version, as described [[https://blogs.technet.microsoft.com/networking/2016/07/18/announcing-new-transport-advancements-in-the-anniversary-update-for-windows-10-and-windows-server-2016/|here]], the Initial Congestion Window 10 probably. If this is important – I hear following [[https://rfe04.akacast.akamaistream.net/7/509/437762/v1/ibb.akacast.akamaistream.net/rfe04?download=1|stream]] for example, but I think any other stream should also do the job. I would like to debug the network stack in the guest, but I don’t know how.

VM is running in the NAT mode. I hope that my description of the issue is clear, in spite of so much text.",boxer01
16383,cannot ping but can ssh and http,VirtualBox 5.1.12,2017-01-13T06:12:33Z,2017-01-20T02:17:57Z,2017-01-20T02:17:57Z,"Host: Windows 10
Guest: Centos 5
Network: NAT

Why: cannot ping in guest, but can http or ssh.

Debug: 
 1. Use tcpdump in guest and host, will see icmp request is sent to host and host resent this packet to the target, but after got icmp reply, host will try to resent reply to 10.96.1.19, then return ""unreachable network""
 1. Try to capture virtual machine packet by(there is only lo0 and eth0 interface in my guest):
{{{
VBoxManage.exe modifyvm ""redhat32"" --nictrace1 on --nictracefile1 c:\Users\xxxx\netlog.pcap
}}}
 But nothing is logged.
",JacksonZheng
16128,"Client loses TCP/UDP connectivity, VirtualBox on host uses 100% CPU",VirtualBox 5.1.8,2016-10-30T08:24:52Z,2016-11-24T08:00:57Z,2016-11-24T08:00:57Z,"I have a guest debian server running on ubuntu host (both 64 bits). Networking mode was set to NAT and port forwarding was set for guest ports 22 and 80 to control and use this server.

It worked fine during low-load testing, but when it come to production with some load (1-2 requests per seconds from around the world), following issue was discovered:

- It's happening after some time, usually after 2-3 days but last time it happens after 7 hours only.
- CPU usage of VBoxHeadless process on host jumps and stay at 100%, although there is no any load on the guest.
- Guest system continues to work but it cannot nor accept nor create new TCP connections (existing TCP connections, e.g. early opened ssh session, continues to work).
- Outgoing TCP connection from the guest (e.g. wget) fails with error code ""Network is unreachable"". This error code is a clear sign that ""bad thing happened"".
- DNS resolving on guest fails so it seems that UDP is affected too.
- PINGs from guest are working! So I consider that network, routing, etc is OK, and the bug is in NAT code.

Of course there are no any messages in any logs when it happens.

I think that symptoms are quite similar to Bug #15223, but don't know could they have common reason or not. First discovering this issue in 4.3.old, I've upgraded to 4.3.40 and then to 5.1.8, but the issue is still here.

",Roman Trunov
16120,VirtualBox 5.1.8r111374 aborts Debian guest after random period - NAT?,VirtualBox 5.1.8,2016-10-26T21:56:41Z,2016-11-22T08:28:23Z,2016-11-22T08:28:23Z,"I have a Debian Jessie guest running on a Arch host. After a seemingly random period of time, the guest will transition to the ""aborted"" state. I am yet to observe it happening, I normally notice after I find my VirtualBox guest has disappeared after a few hours. 

I think it's possible that this is associated with an older ticket. Sorry if I have not formatted this ticket correctly, this is my first time doing so.

I will provide any information you require, please ask.



",sam.4325224
16084,ssl connection incorrectly reset when using NAT,VirtualBox 5.0.28,2016-10-20T06:19:10Z,2018-08-08T16:17:15Z,2018-08-08T16:17:15Z,"After upgrading VirtualBox from version 5.0.26 to 5.0.28 on OS X 10.11.6, I noticed that ssl connections created in python with urllib2.urlopen are incorrectly reset on a Debian 8 guest with a single network interface in NAT mode. I attached a minimal python script that almost always fails with the following traceback:
{{{
gzip: stdin: unexpected end of file
tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now
Failed
Traceback (most recent call last):
  File ""./test.py"", line 12, in <module>
    shutil.copyfileobj(xact, pipe)
  File ""/usr/lib/python2.7/shutil.py"", line 49, in copyfileobj
    buf = fsrc.read(length)
  File ""/usr/lib/python2.7/socket.py"", line 380, in read
    data = self._sock.recv(left)
  File ""/usr/lib/python2.7/httplib.py"", line 602, in read
    s = self.fp.read(amt)
  File ""/usr/lib/python2.7/socket.py"", line 380, in read
    data = self._sock.recv(left)
  File ""/usr/lib/python2.7/ssl.py"", line 714, in recv
    return self.read(buflen)
  File ""/usr/lib/python2.7/ssl.py"", line 608, in read
    v = self._sslobj.read(len or 1024)
socket.error: [Errno 104] Connection reset by peer
}}}
I also attached the tcpdump output on both the host and the guest. The issue seems to only occur when the network traffic goes through the host thunderbolt ethernet adapter. If I switch to Wi-Fi, the issue does not occur. Moreover, I am unable to reproduce the problem with curl or wget.",exg
15874,"VBOX session crashes - aborted - on NAT: DHCP offered IP address. Fixed in the past, reintroduced.",VirtualBox 5.1.4,2016-09-01T15:02:53Z,2016-10-27T14:05:46Z,2016-10-27T14:05:46Z,"Hallo

Running Windows 7 guest, hosted in VBox 5.1.4 under Fedora 24. Same problem on RHEL6 and RHEL7.

Session of VM randomly crashes without notice, getting status '''ABORTED'''. No obvious errors in neither Windows not Linux logs. In VBox log, after every crash there is this single message as last one:

'''NAT: DHCP offered IP address 10.0.2.15'''

I've seen same problem beeing solved in much older version of VBox: https://www.virtualbox.org/ticket/13874

I guess the error got reintroduced along the VBox evolution.

Could you please check and fix according to previous solution?

Thanks a lot",Flamestring
15844,vboxmanage option to enable advertising default route for ipv6,VirtualBox 5.1.4,2016-08-22T09:44:26Z,2018-02-12T17:31:41Z,2018-02-12T17:31:41Z,"At the moment this can be configured only via gui, the ticket is a request to make it possible to configure advertising of the default route in NAT network config via cli (vboxmanage)",mwasilewski
15520,vbox/src/VBox/Devices/Network/slirp/resolv_conf_parser.c:476: bad test ?,VirtualBox 5.0.22,2016-06-17T14:19:59Z,2016-06-17T18:38:26Z,2016-06-17T18:38:26Z,"vbox/src/VBox/Devices/Network/slirp/resolv_conf_parser.c:476]: (warning) Logical conjunction always evaluates to false: EXPR == ' ' && EXPR == '\t'.

Source code is

    while (*psz && *psz == ' ' && *psz == '\t')

",dcb
15303,NAT host adapter responds to traffic when it shouldn't,,2016-04-11T23:34:29Z,2017-07-19T11:23:01Z,2017-07-19T11:23:01Z,"When using a NAT network, the host adapter will generate TCP RST packets in response to packets that are not destined for that interface. For example, here we have the following network setup:
{{{
52:54:00:12:35:02 10.0.2.2   VirtualBox router
08:00:27:7c:00:6c 10.0.2.15  VM
}}}
And the VM sends this packet:
{{{
TCP SYN
Src: Eth 08:00:27:7c:00:6c / IP 10.0.2.15  / TCP 15717
Dst: Eth 08:00:27:7c:00:6d / IP 10.0.2.100 / TCP 80
}}}
Then, the VM will receive this spurious packet:
{{{
TCP RST,ACK
Src: Eth 52:54:00:12:35:02 / IP 10.0.2.100 / TCP 80
Dst: Eth 08:00:27:7c:00:6c / IP 10.0.2.15  / TCP 15717
}}}
Note the source MAC. This is the host adapter's MAC. The expected result is that no packet will be sent in response to the original packet above, since the target host does not exist on the network and any other host receiving the packet should disregard it since the destination MAC does not match their MAC.

I have attached a pcap of the problem that was generated like this (nping is part of nmap):
{{{
arping -I enp0s3 -c 1 10.0.2.2
nping --tcp --dest-mac 08:00:27:7c:00:6d 10.0.2.100
}}}
Tested with VirtualBox 4.3.36, 5.0.12 and 5.0.16 using Debian, Ubuntu and FreeBSD.",Mike446
15030,DHCP server on natnetwork doesn't return DNS servers,VirtualBox 5.0.12,2016-01-12T14:24:23Z,2016-01-12T15:16:39Z,2016-01-12T15:16:39Z,"If I start up a guest VM on old school nat networking I see an option 6 come thru with the DHCP response from the virtualbox DHCP server.

If I do the same on a natnetwork'd guest all but one of the same options arrive in the DHCP response, including 15 for a DNS domain name, but option 6 is consistently missing and obviously this means the DNS server is never configured inside the guest.
If I set it manually in the guest to the IP I configured under ""VBoxManage dhcpserver add"" everything works as expected so networking is certainly working.

This is easily observed with a linux guest by installing and running dhcpdump while running ""dhclient -d""",tommyvn
14790,Network communication problem in newer versions of VirtualBox. Possible regression.,VirtualBox 5.0.8,2015-11-05T06:18:32Z,2015-11-07T23:36:28Z,2015-11-07T23:36:28Z,"I recently found that !VirtualBox could no longer communicate with my printer/scanner (same device). The device is attached via network ethernet cable (NAT).

The operating system of the guest is Linux Mint release 17 (qiana) Mate 64-bit. The driver has worked fine for years. After an update of !Virtualbox somewhere in version 4.x, I was able to send print commands but I could no longer communicate with the scanner.

To help narrow down the problem, I tested the exact same operating system and printer driver with 2 different versions of !VirtualBox:

1. !VirtualBox v. 4.2.32 `r101581`: Scanner works
2. !VirtualBox v. 5.0.6 `r103037`: Scanner fails

Scanning hasn't worked for some time; at least since version 5.0 and possibly a bit before that. I estimate that it broke sometime after 4.3. Comments in !VirtualBox's forum indicate that it's a possible regression because nothing has changed except for the !VirtualBox version. Every time I downgraded or upgraded !VirtualBox, I always installed the corresponding guest additions for that particular version. I tested with version 5.0.8 `r103449` also; the problem persists.

To replicate the problem:
1. Install Linux Mint 17 Mate 64-bit as the guest. The host can be anything. It's a guest problem.
2. Install scanner and printer drivers for Lexmark Pinnacle Pro901. These are the respective files:

http://support.lexmark.com/index?docLocale=en_US&page=content&id=DR21641&locale=EN&userlocale=EN_US

http://support.lexmark.com/index?docLocale=en_US&page=content&id=DR21637&locale=EN&userlocale=EN_US

3. When installing the printer driver, add the printer to the operating system. Let the operating system detect the printer, then use AppSocket/HP JetDirect. The IP of the printer will be automatically detected without having to choose AppSocket/HP JetDirect.

4. There is a cups-insecure-filter error when you try to print. This is easily fixed:
{{{
cd /usr/local/lexmark/v3/bin/
sudo chmod 755 printfilter
}}}
Printing isn't the problem though. I include this just to be thorough.

5. Install any scanning program. gscan2pdf and Simple Scan both work well. On older versions of !VirtualBox (up to about the 4.2 I tested, possibly up to around 4.3), scanning will work just fine. All later versions cut off access to the scanner; the scanning program will say no scanners were detected.

// End of steps for reproducing the problem

A log file has been attached. During the time the log was created, I powered on the virtual machine, successfully tested that a printed document could be sent to the printer, tested the scanner (which failed), and then powered it off. I'll be happy to provide more details that might be relevant.",misterpenguin
14748,nat network hangs intermittantly,VirtualBox 5.0.8,2015-10-26T12:17:06Z,2021-05-04T20:17:25Z,2021-05-04T20:17:25Z,"Host: Ubuntu 14.04 64Bit

Virtualbox 5.0.8

Guest: Windows Server 2012, Windows XP - defect present for both guests.

Both guests are headless, used only by RDP.

Sometimes (1-2 times per day) guest network adapter stops to recieve any packets from ""media"", can't ping default gw for this network interface.

The only things that fix issue is nat network restart:

{{{
VBoxManage natnetwork stop --netname nat-int-network-2
VBoxManage natnetwork start --netname nat-int-network-2
}}}

Of course, may be there are another ways... reboot particular guest or perform ""sudo  /etc/init.d/vboxdrv restart"" (requiring all VMs stop)... But the only way I found to fix issue (while not rebooting/stopping guest is restart nat network...
 
I have two nat networks (192.168.1.0/24 and 192.168.2.0/24). They hangs indpendently:

- First one, nat-int-network (192.168.1.0/24), connected to WinXP guest (single network adapter within guest) hangs rarely - 1-2 times per month. 

- Second one, nat-int-network-2 (192.168.2.0/24), connected to Windows Server 2012 Guest (one of two network adapters within guest, second one is openvpn tap0 interface attached to guest as Bridged Adapter) and hangs more often - 1-2 times per day... sometime 1 time per 2-3 days...

Windows Server guest is a loaded by 5-10 simultaneous RDP-sessions, but average load is quite moderate... 

I understand that info provied is not enough.
Please, let me know - what kind of details should I add to?",dtgeorge
14616,Firefox.com Firefox can't completely Download files,VirtualBox 5.0.4,2015-09-21T13:46:37Z,2015-09-22T15:26:48Z,2015-09-22T15:26:48Z,"I have been running into what appears to be a bug with !VirtualBox.  

Host OS is Windows7 SP1 x64 with the latest updates.
Guest OS is Centos 7.1 x64 with the latest updates. 

When we use Firefox from www.firefox.com,  it freezes when we try to download a file.

Steps to reproduce:

1.  Start Guest OS
2.  Immediately launch Firefox (38.2.1ESR or the latest 40.x release) and try to download a file (In our case, it is a epub file, http://www.cse.yorku.ca/~jr/epub/w/CV.epub)
3.  Firefox should them freeze

If you close the VM and restart the VM, Firefox should be able to download the file. If you reboot the host and retry the steps above you will reproduce the FF download failure. 


If you look a Wireshark trace during the download you actually see the file start to download, but it seems that it isn't getting fully processed/closed/or TCP session closed. 

Google Chrome/wget  doesn't have this issue. It seems to tied to the FF from firefox.com

I am able to reproduce this with !VirtualBox 5.0.2 and 5.0.4. !VirtualBox 4.3.30 doesn't have this issue.

See the attached log and network captures.",paulg.ca
14470,NAT Network failing to provision gateway,VirtualBox 5.0.2,2015-08-18T18:56:35Z,2015-08-18T21:01:03Z,2015-08-18T21:01:03Z,"Creating a new NAT Network using the GUI WITHOUT DHCP server results in a network with the gateway address at x.y.z.1 however gateway fails to respond to ping and fails to forward traffic upstream.  Stopping and restarting VirtualBox does not resolve gateway non-functionality.

NAT Network created WITH DHCP server responds to ping and forwards traffic upstream.  Removing/disabling the DHCP server does not cause loss of gateway functionality.  Functionality maintained across restart of VirtualBox.",VirtualBryan
14414,No DNS server information on DHCP enabled NATNetworks,VirtualBox 5.0.0,2015-08-07T13:43:58Z,2015-08-17T19:28:16Z,2015-08-17T19:28:16Z,"I've configured a NATNetwork with DHCP enabled:

{{{
NetworkName:    NatNetwork
IP:             10.0.3.1
Network:        10.0.3.0/24
IPv6 Enabled:   No
IPv6 Prefix:    
DHCP Enabled:   Yes
Enabled:        Yes
loopback mappings (ipv4)
        127.0.0.1=2
}}}

It created a DHCP server configuration like this:
{{{
NetworkName:    NatNetwork
IP:             10.0.3.3
NetworkMask:    255.255.255.0
lowerIPAddress: 10.0.3.4
upperIPAddress: 10.0.3.254
Enabled:        Yes
}}}

When the VM is started it requests the IP address to DHCP server. On the DHCP response (DHCP ACK package) there is no DNS information, but there is the Domain Name (DNS suffix).

If I manually configure the DNS in the virtual machine to 10.0.3.1 the name resolution works.
",jacksonfoz
14331,PXE boot fails on NAT network,VirtualBox 5.0.0,2015-07-27T12:01:55Z,2015-07-27T15:26:39Z,2015-07-27T15:26:39Z,"Hello,
I created guest(Linux/Red Hat 64-bit). Set NAT network for this guest.
I set external tftp server and file:
{{{
alexey@rualty-mac:~$ VBoxManage modifyvm ""test4"" --nattftpserver1 192.168.2.2
alexey@rualty-mac:~$ VBoxManage modifyvm ""test4"" --nattftpfile1 pxelinux.0
}}}
According to tcpdump guest successfully download pxelinux.0 form server, but couldn't get  config file.
Server several times retried to send file to the guest (see attach pxe-nat-doesnot-work.txt).
While PXE boot through bridged network works fine (see attach pxe-bridged-works.txt) 
",Alexey Tyapkin
14213,NAT networking stops responding blocks all I/O on that interface for Ubuntu/Debian x64 guests,VirtualBox 4.3.28,2015-06-19T18:21:50Z,2015-06-19T23:06:42Z,2015-06-19T23:06:42Z,"= Summary =
I can reproduce almost 100% this fault, which seems to affect Virtualbox versions 4.3.x in both Windows 8.1 and Windows 10 using ubuntu 14.04.2 or debian Jessie guests.

I attached a script, which pings a well known site once a second that you can run to show the precise moment at which networking stops responding. You may use this script or any tool you like for this. For the purposes of the bug description I will assume you are using the embedded script.

= Repro steps to detect fault =

1. Make sure you have a standard NAT based single interface ubuntu guest running.
2. Log-in to guest.
3. Install either google chrome (triggers fault immediately) or chromium-browser (ubuntu) or chromium (debian jessie) which trigger very often but not 100% of the time. Install google-chrome using the following snippet:

{{{
wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add - 
echo ""deb http://dl.google.com/linux/chrome/deb/ stable main"" | sudo tee /etc/apt/sources.list.d/google-chrome.list
sudo apt-get -yqq update
sudo apt-get install -yqq google-chrome-stable
}}}


4. Start embedded script to monitor network, access.
{{{
Expected result: It should be possible to ping well known address, the
 result should be something along these lines:
...
1 packets transmitted, 1 received, 0% packet loss, time 0ms
...
}}}

5. Start chromium browser from UI and try to access google.com or any address.

{{{
Result: Scripts start showing that network access is broken. Lines like
the following one show in script after a small delay where everything is
frozen:
...
1 packets transmitted, 0 received, 100% packet loss, time 0ms
...

Result 2: Virtualbox process in Windows becomes unresponsive and unstable,
cannot be easily stopped, may turn windows blank as hung processes show.

}}}
 
{{{
Expected result: Network access should work normally, no disruptions.
}}}

= Script to trigger fault =

For repro steps I used:
{{{
./net_tester.sh -x
}}}

{{{
$ cat net_tester.sh 
#!/bin/bash

function usage()
{

  cat <<eof

Usage: $(basename $0) [-x] [-h] [output log file]

The purpose of this script is to check network reliability of Virtualbox

Options:

-x, --external  Uses the google DNS to ping instead of NAT gateway address.
-h, --help      This message.

eof
  exit 1
}

#
# Change the following line to the address of the NAT gateway.
#
ping_address=10.0.0.2
out_file=out.log

while [ ""$1"" != """" ]
do
  case ""$1"" in
  -h|--help) usage ;;
  -x|--external) ping_address=8.8.8.8 ;;
  *) out_file=$1 ;;
  esac
  shift
done

while :
do
  date
  ping -c 1 ${ping_address}
  sleep 1
done | tee ${out_file}

}}}

",Coffee_fan
14189,Port forwarding silently fails when source ports are privileged,VirtualBox 4.3.28,2015-06-09T21:21:38Z,2015-06-09T23:38:27Z,2015-06-09T23:38:27Z,"I just spent a really unproductive hour or so trying to work out why I was getting ""Connection refused"" from a test LDAP server in a VM.

Then I resorted to trying to forward the port using SSH. The SSH client reminded me that privileged ports cannot be forwarded unless you're root. (Oh yeah, Unix. Privileged ports. I remember now.)

So my suggestion is:

 - The VirtualBox GUI should warn the user about this.

 - There should be an error displayed if port forwarding fails because the port is privileged.

The documentation at https://www.virtualbox.org/manual/ch06.html mentions the limitation, but it states that the VM will refuse to start in such a situation. That doesn't appear to be true -- I tried restarting the VM and didn't get a useful error message.",meta
14049,VirtualBox NAT implementation tcp keep-alive problem,VirtualBox 4.3.10,2015-04-14T21:59:14Z,2015-04-15T13:25:24Z,2015-04-15T13:25:24Z,"Guests behind VirtualBox NAT have problem using TCP keepalive.
When connection with remote is lost (i.e. even host OS reports no connection), VirtualBox NAT implementation continues to reply to guest OS keepalive requests, hence guest cannot detect TCP connection loss.[[BR]]

Encountered on:
Host OS: Windows 7 Professional 64
VirtualBox 4.3.10
Guest OS: Ubuntu 12.04 32

The same problem was reported by two users on the forum: https://forums.virtualbox.org/viewtopic.php?f=7&t=52384
",Aegis
13967,NatNetwork limits mtu,VirtualBox 4.3.26,2015-03-18T13:43:20Z,2016-01-05T16:20:19Z,2016-01-05T16:20:19Z,"I have 4.3.26 in win7 running.

My guests are linux (redhat 5,4 5.10, opensuse 13.2, ...)

All are connected to a virtualbox NatNetwork

Inside the guests an openvpn client is started and i see, that huge packets that the openvpn client sents will be dropped. I investigated further and found out, that the highest Packet size leaving the host is 1295 bytes long.

",RobbySherwood
13847,vpnc no response from target after upgrade to 4.3.20 and 4.3.22,VirtualBox 4.3.22,2015-02-17T14:20:10Z,2015-08-30T23:54:57Z,2015-08-30T23:54:57Z,"Host is Win7, Guest is OEL6.  Have been using vpnc to connect to Cisco VPN for several years.  After upgrade of VirtualBox from 4.3.12 to 4.3.20 it stopped working with ""vpnc: no response from target"". Restarting guest and host did not help. Downgrading to VirtualBox 4.3.12 resolved the issue. Tried upgrading to VirtualBox 4.3.20 again, just in case a driver got hosed during first attempt, but it did not work.  Reverted back to 4.3.12 and having been running that for months now.

Today I tried upgrading to VirtualBox 4.3.22, hoping the issue would be fixed, but it still doesn't work.  I tried the same reboot guest and host after upgrade but no luck.  Reverted back to 4.3.12 and it works fine now.",Dave Musci
13743,NAT: port forwarding issues / collision,VirtualBox 4.3.18,2015-01-07T11:28:33Z,2015-01-07T11:28:33Z,2015-01-07T11:28:33Z,"Host: Windows 7, Core i7, VBox 4.3.18

Guests: Linux, RHEL6 (CLI-only)

Setup localhost + 2 web servers VMs.

VM1: NAT host@1443 -> guest:443 (default 10.0.2.15 IP)

VM2: NAT host@2443 -> guest:443 (default 10.0.2.15 IP)

I connect by typing in local web browser:
https://localhost:1443

When I connect via HTTPS to first VM, it's okay, but when I connect to
second VM, the first one disconnects (connection timeout), and then I
get access to 2nd VM, and after I try to reconnect to 1st VM, 2nd VM
immediately disconnects, so there is some collision between NAT engine
on both VMs.

No way to connect to both VMs, from localhost web browser.

Not sure why this happens, as SLIRP NAT module is supposed to be
user-space, per-VM process.

I also ensured, that MAC addresses were different in 2 VMs.

--

-Alexey Eromenko ""Technologov"", 07.Jan.2015",Technologov
13678,Networking Still Works After Not Installing,VirtualBox 4.3.20,2014-12-10T08:36:05Z,2014-12-10T11:15:37Z,2014-12-10T11:15:37Z,"During installation it's possible to opt out of installing VirtalBox's networking features. However, despite this, it's still possible for VMs to connect to the host's network via NAT under the networking tab within its settings.

For the purposes in which the VM is to be used, I don't want it to be possible for the user to connect to the network/internet in any shape or form. I have tried this on both the stable, and the test version of VirtualBox (4.3.21).",Pearson.S2
13169,[feature-request] Network: Promiscuous mode for NAT,VirtualBox 4.3.12,2014-07-06T10:28:06Z,2014-07-16T13:52:52Z,2014-07-16T13:52:52Z,"Hi,

I have 2 VMs with SSH servers on my host. I use user-space NAT. Host has IP: 192.168.4.82

I would like to be able to make a NAT route from a different host IP, like 192.168.4.201 and x.x.4.202 for those 2 VMs. I would be nice if VirtualBox NAT router could enter into ""promiscuous mode"" and allow the host listening on custom addresses (similar to what WinPCAP/libpcap and Wireshark do).

Today I have to use non-standard ports for this. Like:  

VM1:

Rule 1 | TCP | [blank host IP] | host port = 1001 | [blank guest IP] | Guest Port = 22

VM2:

Rule 1 | TCP | [blank host IP] | host port = 1002 | [blank guest IP] | Guest Port = 22

I would like to achieve this:

VM1:

Rule 1 | TCP | 192.168.4.201 | host port = 22 | [blank guest IP] | Guest Port = 22

VM2:

Rule 1 | TCP | 192.168.4.202 | host port = 22 | [blank guest IP] | Guest Port = 22

-Alexey Eromenko ""Technologov"", 6.July.2014",Technologov
13104,Network issues on OS X 10.10 Yosemite,VirtualBox 4.3.12,2014-06-06T15:33:43Z,2015-04-21T05:39:58Z,2015-04-21T05:39:58Z,"I'm having trouble with guest network connectivity with Virtualbox 4.3.12r93733 running on OS X 10.10 Yosemite build 14A238x. There seem to be two issues with a Ubuntu Trusty VM i created using vagrant:

- Network connections (e.g. ssh sessions) to the VM keep hanging for 1-2min. When typing in ssh sometimes the shell is unresponsive for a couple of minutes.
- Network connections from the VM to the internet fail often (~50% ping drop), also this problem happens: http://stackoverflow.com/questions/24060099/docker-failed-to-pull-images-from-registry

I've tried: Restarting host / guest, recreating the VM, playing around with network settings (although I don't know much about that).

Let me know if you need any more details, I'm happy to help anyway I can.",lclemente
13002,Slow DNS resolving with enabled natdnsproxy,VirtualBox 4.3.10,2014-04-29T15:50:12Z,2015-08-25T08:17:27Z,2015-08-25T08:17:27Z,"Outgoing network connections are very slow with VMs using 3.13+ kernel.

Below you can see the curl connect phase is taking 5+ seconds.  Problem exists reguardless of using virtio or intel adapters.

{{{
vagrant@vagrant-ubuntu-trusty-64:~$ curl -o /dev/null -s -w %{time_connect}:%{time_starttransfer}:%{time_total}\\n https://www.google.com
5.559:5.703:5.706
vagrant@vagrant-ubuntu-trusty-64:~$ uname -a
Linux vagrant-ubuntu-trusty-64 3.13.0-24-generic #46-Ubuntu SMP Thu Apr 10 19:11:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
vagrant@vagrant-ubuntu-trusty-64:~$ lsmod
Module                  Size  Used by
vboxsf                 43786  1
nfsd                  280297  2
auth_rpcgss            59338  1 nfsd
nfs_acl                12837  1 nfsd
nfs                   236636  0
lockd                  93977  2 nfs,nfsd
sunrpc                284404  6 nfs,nfsd,auth_rpcgss,lockd,nfs_acl
fscache                63988  1 nfs
dm_crypt               23177  0
ppdev                  17671  0
psmouse               102222  0
serio_raw              13462  0
parport_pc             32701  0
parport                42348  2 ppdev,parport_pc
vboxguest             248441  2 vboxsf
ahci                   25819  1
libahci                32168  1 ahci
e1000                 145174  0
}}}

Here is my Vagrantfile that allows for simple re-creation of this issue:

{{{
 -*- mode: ruby -*-
# vi: set ft=ruby :

# Vagrantfile API/syntax version. Don't touch unless you know what you're doing!
VAGRANTFILE_API_VERSION = ""2""

Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
#  config.vm.box = ""ubuntu/trusty64""
  config.vm.box = ""ubuntu-trusty64-20140429""
  config.vm.box_url = ""http://cloud-images.ubuntu.com/vagrant/trusty/20140429/trusty-server-cloudimg-amd64-vagrant-disk1.box""

  config.vm.network :private_network, ip: ""192.168.33.10""
  config.vm.synced_folder "".."", ""/vagrant""

  config.vm.provider :virtualbox do |vb|
     vb.gui = false
     vb.name = ""slowconnection""

     # Use VBoxManage to customize the VM. For example to change memory:
     vb.customize [""modifyvm"", :id, ""--memory"", ""1024""]
  end
end
}}}

nslookup on www.google.com is fast, netperf is fast, download of files are fast once connection is made, mtr is fast (low response times).",rynop
12600,Allow dns proxy in the new NAT Network mode,VirtualBox 4.3.6,2014-01-11T16:34:03Z,2018-01-16T13:37:54Z,2018-01-16T13:37:54Z,"I would like to be able to activate DNS proxy in the new NAT Network mode as it is possible in NAT mode (with the command VBoxManage modifyvm ""VM name"" --natdnsproxy1 on).

As it is, if I set my VM with the new NAT Network mode and run the command (VBoxManage modifyvm ""VM name"" --natdnsproxy1 on), this change nothing and continue to give the host DNS server to the guess.

Allowing this setting would be awesome as it would completely shield the VM from host change while allowing VM to talk to each other.",djf_jeff
12369,NAT Network -  DHCP problem: no DNS,VirtualBox 4.3.2,2013-11-17T23:47:23Z,2014-12-02T12:33:10Z,2014-12-02T12:33:10Z,"Postby petardo » 17. Nov 2013, 03:20
I am using the ""NAT NETWORK"" Network Adapter.
I have found a DHCP SERVER problem:
IF
- DHCP SERVER is enabled in the file / preferences / network / nat network section,
- and NAT NETWORK is selected as natwork adapter for the guest
==> NO DNS values get forwarded to the guest",petardo
12174,Configure internal DHCP server to pass arbitrary domains,VirtualBox 4.2.18,2013-10-10T12:32:39Z,2013-10-10T13:25:31Z,2013-10-10T13:25:31Z,"Hi, 

virtualbox uses it's own internal DHCP server if the network interface type of a VM is set to 'NAT'. 

Unfortunaly I was unable to make VB's DHCP to offer any domain name. Although VBoxManage supports a --natdnspassdomain option, this can just turn domain passing on and off, and did not have any effect. I did not find a hint in the manual, where VB takes the domain from it is supposed to pass through. 

Would be quite useful if VB would allow to just configure which domain name is to be passed by the internal DHCP server to the VM. So one could set any random default domain. 

regards
",DerHadmut
10212,Problem with DNS lookups (NAT),VirtualBox 4.1.8,2012-02-04T17:43:53Z,2012-02-04T18:04:02Z,2012-02-04T18:04:02Z,"NAT network adapter

Running the following shell script on a Debian VM causes DNS lookups to timeout after ~15s of execution

Script:
{{{
while [ 1 ]; do nslookup google.pl; done
}}}

The error is:
{{{
;; connection timed out; no servers could be reached
}}}

It doesn't occur with bridged adapter.
It occurs on all network adapter types (i.e. Intel, PCnet, virtio-net) available in VirtualBox.

Tested on:

Windows 7 host - VirtualBox 4.1.6, 4.1.8

Debian host - VirtualBox 4.1.4
",DragMZ
4427,active FTP doesn't work with NAT,VirtualBox 3.0.0,2009-07-07T23:40:24Z,2019-09-05T02:54:35Z,2019-09-05T02:54:35Z,"This is with a 64-bit OpenSolaris host (2009.06).  It happens with all tested guests (XP, Ubuntu, OpenSolaris, Solaris 10), both with NAT and bridged networking.  The problem did not exist prior to 3.0.0, and has been confirmed both with pre-existing guests and newly created guests.

When you open an FTP session from the guest to the OpenSolaris host, the host returns an error like this one from a NAT guest:

Jun 21 19:50:21 fnog ftpd[1902]: [ID 227848 daemon.warning] refused PORT 10.0.2.15,60783 from fnog [192.168.99.22]

192.168.99.22 is the host IP.

If you do the same with VB 2.2.4 on the same host, ftpd logs no errors and successfully connects the guest.  This has been tested on two different hosts.  Both tested installations of the host OS use an unmodified default ftp configuration.

With FTP servers on the Internet, VB guests connect, but are unable to list files or directories on the FTP server using either the 'ls' or 'dir' commands.  The same FTP servers interact normally with computers that are not VB guests.  One tested example would be ftp.sunfreeware.com.

Shared folders and SSH/SCP/SFTP exhibit no observed problems from guest to host, but are slower for large transfers and for network testing.

I will be attaching a log file soon.",bqbauer
