I'm experiencing a rather strange problem, which I haven't encountered before. I have two AIX-nodes on the same subnet/vlan, both configures with the correct subnet mask. This vlan is directly connected to fwsm and no icmp packets are permitted through the fw, only a few management-ports are.
The two AIX-nodes have two interfaces, one for client traffic and one for management-traffic. When pinging between the two "client"-interfaces, everything works fine. ICMP can go on forever, withouy any packet loss.
But once I try to ping between the two managment-interfaces, I get anywhere from 25% to 80% packet loss. Sometimes the icmp goes on for a good period of time without any interruption, but suddently and for no apparent reason, it fails.
The two aix-nodes are virtual, running on IBM Power6 hardware. The Power6 is connected to the network via an 2x1Gbps etherchannel, and the two virtual adaptors on the Power6 share one physical adaptor.
I've done a trace on the switch which shows, that everytime the icmp fails, the gateway-address for the subnet responds with a 'ICMP Destination unreachable (Network unreachable)'. I just can't seem to understand, why the icmp packets would even be forwarded to the gateway, since both nodes reside within the same vlan. I'm not an authority on AIX, but so far I can't any mistakes in the ipconfig. The addresses and subnet masks are correctly configured and there are no hostroutes on the aix-nodes that would interfere in anyway.