Strange networking behavior

Strange networking behavior

[Peter Osuchowski]

Hello,

I've noticed this strange networking behavior while running kvm-59 modules and 
qemu on a custom-compiled 2.6.24-rc5 kernel on x86_64 (2 x Opteron 2210). 
When I ping a VM from the host it's running on, I get the following result:

talithaA ~ # ping 10.0.1.1
PING 10.0.1.1 (10.0.1.1) 56(84) bytes of data.
64 bytes from 10.0.1.1: icmp_seq=1 ttl=64 time=850 ms
64 bytes from 10.0.1.1: icmp_seq=2 ttl=64 time=389 ms
64 bytes from 10.0.1.1: icmp_seq=3 ttl=64 time=0.353 ms
64 bytes from 10.0.1.1: icmp_seq=4 ttl=64 time=0.366 ms
64 bytes from 10.0.1.1: icmp_seq=5 ttl=64 time=0.361 ms
64 bytes from 10.0.1.1: icmp_seq=6 ttl=64 time=739 ms
64 bytes from 10.0.1.1: icmp_seq=7 ttl=64 time=740 ms
64 bytes from 10.0.1.1: icmp_seq=8 ttl=64 time=741 ms
64 bytes from 10.0.1.1: icmp_seq=9 ttl=64 time=1742 ms
64 bytes from 10.0.1.1: icmp_seq=10 ttl=64 time=731 ms
64 bytes from 10.0.1.1: icmp_seq=11 ttl=64 time=0.373 ms
64 bytes from 10.0.1.1: icmp_seq=12 ttl=64 time=0.380 ms
64 bytes from 10.0.1.1: icmp_seq=13 ttl=64 time=0.383 ms

--- 10.0.1.1 ping statistics ---
14 packets transmitted, 13 received, 7% packet loss, time 13005ms
rtt min/avg/max/mdev = 0.353/456.630/1742.288/509.780 ms, pipe 2

On the other hand, when I ping something on the network from the VM, I get:

talithaA-v00 ~ # ping 172.16.1.1
PING 172.16.1.1 (172.16.1.1) 56(84) bytes of data.
64 bytes from 172.16.1.1: icmp_seq=1 ttl=64 time=1011 ms
64 bytes from 172.16.1.1: icmp_seq=2 ttl=64 time=2.81 ms
64 bytes from 172.16.1.1: icmp_seq=3 ttl=64 time=1000 ms
64 bytes from 172.16.1.1: icmp_seq=4 ttl=64 time=1.37 ms
64 bytes from 172.16.1.1: icmp_seq=5 ttl=64 time=1000 ms
64 bytes from 172.16.1.1: icmp_seq=6 ttl=64 time=1.37 ms
64 bytes from 172.16.1.1: icmp_seq=7 ttl=64 time=1000 ms
64 bytes from 172.16.1.1: icmp_seq=8 ttl=64 time=1.37 ms

--- 172.16.1.1 ping statistics ---
9 packets transmitted, 8 received, 11% packet loss, time 8007ms
rtt min/avg/max/mdev = 1.375/502.390/1011.591/500.668 ms, pipe 2

The two networks above (10.0.0.0/8 and 172.16.1.0/24) are on seperate Qemu 
VLANs. The hardware is a Dual Quad-Core Opteron 2210 server and I'm using the 
default (NE2000) virtual NICs. The host machines have no networking problems.

If anyone could offer any advice, I would be most grateful.

Thanks,
Peter


-- 
Peter Osuchowski
Hosting Operations Engineer
Turtol, LLC.
peter-UI6FQe41Wa3QT0dZR+AlfA@public.gmane.org
http://www.turtol.com

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Re: Strange networking behavior

[Jim Paris]

Peter Osuchowski wrote:
> talithaA ~ # ping 10.0.1.1
> PING 10.0.1.1 (10.0.1.1) 56(84) bytes of data.
> 64 bytes from 10.0.1.1: icmp_seq=1 ttl=64 time=850 ms
> 64 bytes from 10.0.1.1: icmp_seq=2 ttl=64 time=389 ms
> 64 bytes from 10.0.1.1: icmp_seq=3 ttl=64 time=0.353 ms
> 64 bytes from 10.0.1.1: icmp_seq=4 ttl=64 time=0.366 ms
> 64 bytes from 10.0.1.1: icmp_seq=5 ttl=64 time=0.361 ms
...
> The two networks above (10.0.0.0/8 and 172.16.1.0/24) are on seperate Qemu 
> VLANs. The hardware is a Dual Quad-Core Opteron 2210 server and I'm using the 
> default (NE2000) virtual NICs. The host machines have no networking problems.

The NE2000 code appears to be very broken.  Use rtl8139 instead and
you should get better results.

-jim

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