Comment 25 for bug 638955
Revision history for this message
| Stefan Hajnoczi (stefanha) wrote Re: [Bug 638955] Re: emulated netcards don't work with recent sunos kernel | #25 |
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a60fb26
(Get the code!)
On Mon, Feb 28, 2011 at 7:06 PM, geppz <email address hidden> wrote:
> Going with tcpdump -e from within the guest, I have identified that the problem is when a big enough packet is outputed.
> I tried a few times with dmesg, and as soon as the tcp packet reaches the following length:
>
> 18:38:28.340097 52:54:69:b5:89:11 (oui Unknown) > 00:19:b9:81:2c:52 (oui
> Unknown), ethertype IPv4 (0x0800), length 1514: 192.168.7.38.ssh >
> 192.168.7.52.59008: Flags [.], ack 2824, win 64436, options [nop,nop,TS
> val 27488132 ecr 6063255], length 1448
>
> it cannot get through. Then the IP stack tries and retries to send the
> same identical packet, but there will never be any reply from the other
> side. Finally the socket is torn down.
>
> I have bridged networking for the VM. My bridge is a normal linux bridge br0 with MTU 1500.
> Has MTU anything to do with all this?
> Is it a linux-bridge bug or a qemu-kvm bug?
Excellent, thanks for posting these details. The bug is probably in
the NIC hardware emulation and I think we can track this one down
fairly easily.
Can you please post your qemu-kvm command-line including the NIC model
that you are using?
Stefan