RE: Interesting TCP/IP Problem I had yesterdsy.

When most system learn a route from the default router, they save that
route as long as a connection is maintained. These routes do timeout
and flush from route cache once they are no longer used. OS400 / i5OS
does work this way as well, that is if you do not enter a static route.



Chris Bipes
Director of Information Services
CrossCheck, Inc.


-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Harvell, Joel
Sent: Wednesday, June 11, 2008 6:24 AM
To: Midrange Systems Technical Discussion
Subject: Interesting TCP/IP Problem I had yesterdsy.

On one of our remote sites we had a problem connecting to our mainframe
at our Corp Office. Earlier that day the remote site had a problem with
the internet and the network switched operations over to a backup
connection. This backup connection is very, very slow. The AS400
automatically switched it's routing information over to the backup
connection. When you did a NETSTAT command you could see the system
using the Backup Gateway on the routing information screen. The problem
was that when the network problem was resolved the as400 never switched
back to the default route. It continued to use the slower backup route.
We resolved the problem by having one of our network guys disable the
backup gateway. Once it was unavailable the system automatically
switched back to the default gateway.



My question is... Is there a best practice to handling switching from
one route to another. Looking at Iseries navigator I saw where I could
have just deleted the routing information. Would this have fixed the
problem too? Would the as400 started using the default route if I
deleted the slower one that was created when the network switched to the
backup? Shouldn't the system do this automatically??