OK
Sun E420R server
Solaris 7

Command:
route add default ###.###.###.###

15 Seconds later my router is rebooting and will continue this until I flush the route table on the server

Any ideas?! Help!!

What kind of route (numbers) are you trying to add and where does that route go? Give a little bit more info...

Even if the unix host was misbehaving in some way, a router should never crash. If your router is rebooting repeatedly, it is broken. You need to persue this with your router vendor. They may have a patch or something. Also check your router documentation. I'll bet that there is a log in router that will reveal why it crashes.

I have been through all the router stuff
Its a known thing that if you overload a router specified port, which I will resist typing it will crash or force a reboot. I tested this out with 4 different types and different class routers. Happened each time. I get the feeling of a virus, or something running on the box that I never authorized.

If you really want the numbers for the command:
route add default 192.168.212.1

Nothing specific just routed everything to the router.
This machine is supposed to be only running Raid Managers and Oracle Databases, which is what I see in the poled system. Nothing looks out of the ordinary.