router ARP Update

[sagia]

dear engineers,

we do have cluster mail server with a single virtual IP address. whenever there is a failover happens remote clients cannot connect to the current active node.

the router dont know the mac address of the new active node , untill it send a arp request. is there any configuration steps on router to smart identify those both mac addresses whenever they go active.

somebody saying a technique 'route arp cache updatable' . is ther anything like that..

please advise me.

regards

mohamed

[rjackson]

The router will update its arp entry immediately if the server pings the router after it fails over. See if you can set up a script in the failover process to ping the router.

On the other hand, I've seen failover processes in routers, NT servers, firewalls, AIX host and Novell servers. They all handle the mac issue by using a shared mac address along with the shared IP address. Maybe you dont have it set up right.

[wkumari]

The server should send a gratuiotous arp when it determines that it is the master. If it pings the router from the new shared IP that should work. If it is not working for some reason, you could make the arp timout much lower on the router, but that will generate lots more ARP requests.....

Warren.

[gurkang]

hi Mohamed,

You can set the arp timeout enough small like 5 seconds or 10 under the ethernet interfaces. but it will affect all connections on the interface because the address learning mechanism.

ex:

int e0

arp timeout 5

best regards,

Gurkan