Bridges problem with kvm

[carlopmart <carlopmart@gmail.com>]

Hi all,

  I have a strange problem with my bridges configuration. I have a 
rhel5.4 host with kvm-83-105 package installed. This host has two 
bridged interfaces defined to use with kvm guests:

DEVICE=prodif
ONBOOT=yes
TYPE=Bridge
IPADDR=172.26.50.14
NETMASK=255.255.255.240
DELAY=0
STP=off

and

DEVICE=iscsif
ONBOOT=yes
TYPE=Bridge
DELAY=0
STP=off

  I have installed two kvm guests (rhel5.4 also) with two virtual 
interfaces using virtio driver on one guest and e1000 driver on the 
other guest.

  My problem is: when I do a ping between these guests over prodif 
bridge all works as expected: ping responds. But if I do another ping 
over iscsif bridge doesn't works. The only difference between prodif 
bridge and iscsif bridge is that prodif has an IP address.

  More info:

  a) brctl show on host:

bridge name     bridge id               STP enabled     interfaces
iscsif          8000.c201b3289830       no              vnet3
                                                         vnet1
prodif          8000.226af089f4c3       no              vnet2
                                                         vnet0

  b) sysctl.conf on host:

net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0

  I don't have iptables rules defined and net.ipv4.ip_forward is 
disabled (but if I put sysctl -w net.ipv4.ip_forward=1, result is the same).

  What am I doing wrong??

  Many thanks.

-- 
CL Martinez
carlopmart {at} gmail {d0t} com