topic Re: Network switching, will packet fail ? in Operating System - HP-UX

Network switching, will packet fail ?

UNIXGRUPPEN — Mon, 23 May 2005 08:04:27 GMT

I've got 4 native network interfaces (and two stand-by) on each node in a cluster configured as below:

NODE_NAME clustnod1
NETWORK_INTERFACE lan0
STATIONARY_IP 10.10.193.49
NETWORK_INTERFACE lan1
NETWORK_INTERFACE lan2
HEARTBEAT_IP 192.168.3.1
NETWORK_INTERFACE lan3
STATIONARY_IP 10.10.222.24
NETWORK_INTERFACE lan7
NETWORK_INTERFACE lan6
HEARTBEAT_IP 192.168.4.1

lan3 has got the STATIONARY_IP 10.10.222.24, and the stand-by card for it is lan7.

We've got to do some maintenance on the switch were all cluster nodes has got their lan3 and lan7.
This is primary not a problem, since lan3 is only used for nightly backups.

Will this force any packet on these nodes to fail ?
The other STATIONARY_IP, lan0, and both heartbeats will be up and running.

In the packages configs:
LOCAL_LAN_FAILOVER_ALLOWED YES
But as far as I can tell, this will only allow the cluster service to switch from lan3 to lan7.
The question is, what will happend when all three nodes loses both lan3 and lan7 simultaneously ?

Regards,
Johan

Re: Network switching, will packet fail ?

Steven E. Protter — Mon, 23 May 2005 08:13:31 GMT

If your setup is solid, some packets will fail. Then the SG setup will fail over. There should be minimal disruption of the applications though.

This is really something that needs to be tested in a pre-production test. But as they used to say at the JUF, if it works, its production.

So, some packets will fail, be retried and all should work through the maintenance.

SEP

Re: Network switching, will packet fail ?

UNIXGRUPPEN — Mon, 23 May 2005 09:47:43 GMT

Huge TYPO I see :)

"Will this force any packet on these nodes to fail ?"

What I ment was will this force any cluster PACKAGES to fail ?

If lan3 would go broke it would failover to lan7, but in this situation it'll lose both lan3 and lan7.