Network bridging isn't working

[limpens]

I'm running Debian Squeeze and upgraded recently to Virtualbox 4.0.2.

Since the upgrade network bridging isn't working anymore. I use bridging for connecting guests to pptp VPN's (since NAT doesn't support GRE).

I tested Debian (Squeeze) guests as well as Windows Vista Guests, but all fail to work. I've verified that NAT and host-only networking do work. I haven't tested internal networking yet.

For testing I tried all adapters (Intel and PCnet), but these all fail.

I even tried deinstalling 4.0.2 and install 3.2.12 but network bridging stays broken.

In one of the tickets I found a qdisc_debug patch which I deployed on 4.0.2 and then tested again, to see if that would give some more info. But for me it didn't.

the output of tc: qdisc mq 0: dev wlan0 root qdisc pfifo_fast 0: dev eth0 root refcnt 2 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1

Since I depend on using network bridging I hope someone can help me out quickly.

Attached you find:

• the vbox.log
• the debug info from kern.log after deploying the patch

[limpens]

Vbox logging

[limpens]

kern.log after deploying patch qdisc_debug.patch

[Aleksey Ilyushin]

What exactly is not working? Can you ping the host or the router? In the statistics part of the log I see that the guest did send and receive some packets. VPN connection fails to establish? If so, start with checking MTU size in the guest, both Wi-Fi and GRE reduce MTU, so reducing MTU in the guest may solve the problem. If in doubt paste the output of ifconfig from both host and guest here.

[limpens]

Well the network bridge isn't working. The guests don't get an IP address when using DHCP settings. On fixed IP the guest can't connect to the outside world. So ping is not working as well.

Note: I normally use a network bridge for VPN connection, but it's not the VPN connection which fails. The guest just has no connection to the outside world using the network bridge.

The output of ifconfig is:

ifconfig host (Debian Squeeze): eth0 Link encap:Ethernet HWaddr c8:0a:a9:3e:43:66

inet addr:10.0.0.151 Bcast:10.0.0.255 Mask:255.255.255.0 inet6 addr: fe80::ca0a:a9ff:fe3e:4366/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:393551 errors:0 dropped:0 overruns:0 frame:0 TX packets:214073 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:567981169 (541.6 MiB) TX bytes:14793929 (14.1 MiB) Interrupt:35 Base address:0xe000

ifconfig guest (Debian Squeeze) - while using DHCP settings: eth0 Link encap:Ethernet HWaddr 08:00:27:ac:f8:27

inet addr:169.254.107.29 Bcast:169.254.107.255 Mask:255.255.0.0 inet6 addr: fe80::a00:27ff:feac:f827/64 Scope:Link UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:13 errors:0 dropped:0 overruns:0 frame:0 TX packets:39 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1870 (1.8 KiB) TX bytes:7350 (7.1 KiB)

[Aleksey Ilyushin]

Could you enable internal packet capture with

VBoxManage modifyvm <vm_name> --nictrace1 on --nictracefile1 <name_of_your_choice>

bring up VM and wait for it to get auto-assigned (169.254.x.x) address? Please send the capture file or its tcpdump printout to aleksey dot ilyushin at oracle dot com.

PS. Don't forget to turn off the capture afterwards as it is a persistent property of VM.

[limpens]

Installed some updates on Squeeze just now (including a kernel update) and guess what.. network bridging is working.

So I guess we can close this ticket. Thx for the support and keep up te good work.

[Frank Mehnert]

Thanks for the feedback.