We are currently migrating from vmware server to kvm. So far everything works smooth, with the exception of the secondary bridge.
Our network layout is as follows:
Firewall with 3 ports
eth0 Public Internet IP address eth1 Internal network 192.168.200.x eth2 DMZ internal network 192.168.202.x
On the KVM host we also have two NIC's, one attached to the eth1 port of the firewall and the secondary to the eth2 port of the firewall.
We defined two bridges in the KVM host, so we have a bridge for the internal servers (192.168.200.x) and one for the DMZ servers (192.168.202.x)
The network config of the KVM host looks like this:
auto lo br0 br1 eth0 eth1 iface lo inet loopback iface eth0 inet manual iface br0 inet static address 192.168.200.249 netmask 255.255.255.0 broadcast 192.168.200.255 network 192.168.200.0 bridge_ports eth0 gateway 192.168.200.4 iface eth1 inet manual iface br1 inet static address 192.168.202.249 netmask 255.255.255.0 broadcast 192.168.202.255 network 192.168.202.0 bridge_ports eth1 gateway 192.168.202.4
KVM guest which are located in the 192.168.200.x network (bound to br0) can communicate just fine. But KVM guests with IP's 192.168.202.x (bound to br1) have connectivity only at random. Sometimes the guest have connectivity for 20 seconds, then for several minutes/hours no connection.