Thanks for the suggestion from Jeff Stelnzer to look for duplicate ip
address on net that might affect arp but this wasn't it. DEC U.K.
through their comms specialist traced the problem to the default gateway
disappearing. No default so if a route had been learned then traffic
would get through; if not then host is unreachable. Who said the error
messages in UNIX were ambiguous?
It was what was causing the default route to get whacked that was
interesting. Sysadmins beware! An engineer had installed a Cisco
router to handle some experimental ISDN traffic and had set it up in
accordance with the Cisco recommended config scripts including a default
route and RIP. As this was on the same ethernet segment the Alpha saw
the RIP and gave up its 'routes' defined default for the Ciscos, thus
causing the disaster. The solution was to switch off RIP at the
offending Cisco and shoot the engineer.
More effective use of netstat -rn by me would have been sensible but we
all learn the hard way. Just because you KNOW there is a default route
in routes and saw it after boot up doesnt mean it will stay there.
Regards
Stuart McKenzie
Received on Sat Apr 05 1997 - 19:02:32 NZST