[et-mgmt-tools] Re: ARP failing when I ping from host to guest

[kewlemer]

On 11/4/07, kewlemer <kewlemer at gmail.com> wrote:
> On Nov 4, 2007 1:37 AM, kewlemer <kewlemer at gmail.com> wrote:
> > > To be more specific, I'm doing a tcpdump on guest's
> > > eth0(192.168.122.195). When the host pings 192.168.122.195, I see
> > > following -
> > >
> > > tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
> > > listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
> > > 12:15:49.058031 arp who-has 192.168.122.195 tell 192.168.122.1
> > > 12:15:51.065437 arp who-has 192.168.122.195 tell 192.168.122.1
> > > 12:15:52.069123 arp who-has 192.168.122.195 tell 192.168.122.1
> > > 12:15:53.071852 arp who-has 192.168.122.195 tell 192.168.122.1
> > > 12:15:55.077218 arp who-has 192.168.122.195 tell 192.168.122.1
> > >
> > > When the guest's eth0 is receiving ARP for it's right IP address, why
> > > is it not responding?
> > >
>
> Sorry for the confusion, now on doing tcpdump on guest's eth0, I saw
> that the guest receives host's ARP response (for it's 192.168.99.1),
> but is NOT receiving the host's ARP requests  ("who-has 192.168.99.128
> tell 192.168.99.1").
>
> > I also tried creating new virtual networks with virt-manager as both
> > "Isolated virtual network" and "Forwarding to physical network". Each
> > time I ping the host's virtual interface which is on the same subnet
> > as the guest's eth0, it fails. On doing a tcpdump on host's virtual
> > interface(vnet2), I see that the guest's ARP *is* coming through, but
> > the host is unable to resolve guest's eth0 IP (192.168.99.128 below).
> > Host's virtual IP is 192.168.99.1.
> >
> > [root at fed-amd64 ~]# tcpdump -i vnet2
> > tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
> > listening on vnet2, link-type EN10MB (Ethernet), capture size 96 bytes
> > 01:24:52.588689 arp who-has 192.168.99.128 tell 192.168.99.1
> > 01:24:53.588448 arp who-has 192.168.99.128 tell 192.168.99.1
> > 01:24:54.588226 arp who-has 192.168.99.128 tell 192.168.99.1
> >
> >
> This observation is still valid. Looks like I'm missing something
> basic. Any pointers?
>
I've posted this question on xen-list, kvm-list and this list and
havent gotten a single response. So I don't know if I'm posting this
question on the wrong forum, or if I haven't done my homework (I've
spent a day on this). Can anyone at least tell me if there is a better
forum to post my question ? Can anyone using KVM-QEMU post their
ifconfig and netstat -rn output - I'll check against mine ?

Thanks,
KM