[Fedora-xen] ARP failing when I ping from host to guest

[kewlemer]

I'm running x86_64 Fedora7 host and 32 bit Fedora 7 guest on KVM. Here
what the default bridged network setting gave me -

HOST -

[root at fed-amd64 ~]# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:1A:A0:56:52:E5
          inet addr:192.168.1.9  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::21a:a0ff:fe56:52e5/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1492  Metric:1
          RX packets:4144 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4490 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:3143529 (2.9 MiB)  TX bytes:1026716 (1002.6 KiB)
          Interrupt:23 Base address:0x6000

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:11074 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11074 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:49074613 (46.8 MiB)  TX bytes:49074613 (46.8 MiB)

virbr0    Link encap:Ethernet  HWaddr 00:FF:EE:14:6D:91
          inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0
          inet6 addr: fe80::200:ff:fe00:0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:61 errors:0 dropped:0 overruns:0 frame:0
          TX packets:86 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:9261 (9.0 KiB)  TX bytes:12220 (11.9 KiB)

vnet0     Link encap:Ethernet  HWaddr 00:FF:EE:14:6D:91
          inet6 addr: fe80::2ff:eeff:fe14:6d91/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:61 errors:0 dropped:0 overruns:0 frame:0
          TX packets:61 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500
          RX bytes:10115 (9.8 KiB)  TX bytes:7195 (7.0 KiB)

[root at fed-amd64 ~]#

Here is what the GUEST landed up with when using the default configuration-

[root at fed-guest ~]# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:16:3E:6B:C6:36
          inet addr:192.168.122.195  Bcast:192.168.122.255  Mask:255.255.255.0
          inet6 addr: fe80::216:3eff:fe6b:c636/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1492  Metric:1
          RX packets:4144 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4490 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:3143529 (2.9 MiB)  TX bytes:1026716 (1002.6 KiB)
          Interrupt:23 Base address:0x6000

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:11074 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11074 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:49074613 (46.8 MiB)  TX bytes:49074613 (46.8 MiB)

virbr0    Link encap:Ethernet  HWaddr 00:00:00:00:00:00
          inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0
          inet6 addr: fe80::200:ff:fe00:0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:61 errors:0 dropped:0 overruns:0 frame:0
          TX packets:86 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:9261 (9.0 KiB)  TX bytes:12220 (11.9 KiB)

[root at fed-guest ~]#

The problem is that I'm unable to ping from the host to the guest (to
192.168.122.195). tcpdump shows that guest is not responding to ARPs
for 192.168.122.195. Can anyone tell me why?

When I ping from the guest to to 192.168.122.1 and 192.168.122.195,
both go through. But when I ssh into either of them to make sure I'm
reaching the host, the ssh lands into the guest itself. This means the
ping response on the guest is from itself - so the guest is also
unable to reach the host.

I googled and looked at the following sitew, but they were of not much
help for this problem -
http://www.gnome.org/~markmc/virtual-networking.html
http://watzmann.net/blog/index.php/2007/04/27/networking_with_kvm_and_libvirt

Am I missing something ?

Thanks,
KM