IP Networking

Hello all,

I meet a "strange" situation, at least for me, and i want your opinion.
I have a node used as SIP B2BUA (node A) and i have the following issue.
SIP messages does not reach a client node (node B) but ICMP do.
I see in the pcap that SIP and ICMP messages have different destination MAC address. Only ICMP messages have destination MAC address the MAC of node B.
OS: rhel 6.2
arp table show the MAC of node B.

Any idea?What should i check??

Thanks in advance!

Is this an HA cluster or is there ether-channel or link-aggregation in play here?


Robin

Yes is HA cluster.

A workaround i used to make it work is to create a static arp table.
So i defined in node A the MAC address of the GW to be the MAC of nodeB.

Code:

arp -s <GW IP> <MAC of nodeB>

So the problem you might have with defining a static MAC for an IP address is what would happen if the IP address moves to another server under HA management.

Is this causing a problem to your operating environment or just something unusual you noticed?

Personally I would leave out any static definitions and let the switches manage routing packets to the right server. The only exception could be for the static IP addresses that do not move under HA control, i.e. the ones that only you should know and no-one else uses, even if they are on the same card.



Robin