I'm running a 1.5 box at home which seems to get strange routes added.

It's running thttpd, postfix, imapd and bind straight from pkgsrc.  It
does not run routed or gated at all, but gets routes added to networks I
don't even run.  All of the routes are added using another one of my hosts
as the default gateway, and all are host routes, not network routes.  Are
these ICMP redirects, perhaps?

It's a pretty much stock 1.5 kernel on the i386 platform.

Any help or pointers are definitely appreciated.

-Jon