Route table

[Nilzelio Monteiro]

Hi,
I have a HP-UX 10.20 that is learning some routes dynamically. I don't want it. There was not configured the RIP routing protocol, I think it's learning by ICMP. How can I stop the learning process?

Thanks a lot

[John Palmer · Accepted solution]

You need to disable 'ICMP redirect' in your routers, it's they that are causing this problem.

Example, you have routers A and B. You route via A but A thinks that B is a better route. A will send your system an ICMP redirect telling it to go via B so your system creates a dynamic route pointing to B.

Regards,
John

[Ron Kinner]

As John says your default router is filling up your table with redirects to the router it thinks is a better choice. If you can't get to the router then another thing you can try is to change the default route to point to the second router. I expect it has the best gateway to the internet which would explain why your route tables are growing enough to notice.

In 11.0 there is an ndd parameter to change how long such routes remain in the table. ip_ire_redirect_interval:

All routing table entries resulting from ICMP "Redirect"
messages are deleted after this much time has elapsed,
whether or not the entry has been recently used.
[60000, - ] Default: 300000 (5 minutes)

If you set it to 1 minute (60000) then the table will probably not grow too large to be a problem.
Nothing similar on my old 10.0. Don't have a 10.20 system to play with anymore but you can do a
nettune -l
and see what pops up.

Ron