Ethernet problems with 3.1

[Shawn Hayes]

On one of the computers at work we seem to lose our communications ability
occasionaly.

Today the power went out and all of the computers were turned off(ie. no
shutdown was executed).  Wehen we brought them back up everything was fine
except that one of the RS/6000s was unable to communicate with any other 
computer.  I tried to ping it from another machine without success.

When I logged onto the sick computer everything seemed fine, except for 
network communications.  When I tried to ping another computer I got an
error message of 'send:  no route to host'  which ususally implies that
the host that I'm trying to connect to isn't in the hosts file.  However after
looking at all of the configurations in SMIT everything is as it was and
thes sick RS/6000 was able to communicate earlier.  So I then tried to ping
the sick computer from the sick computer without any luck.  I got the message
that there was no route to host.

After trying a few more things, including a reboot, I was at a loss as to what
could be wrong.   As a final act I shut down the Inet daemon and went to
the TCP/IP mininmum configuration menu (the one where you set the host name and
IP address).  I did not change any data(it was all correct), but did set the
start TCP/IP now flag to TRUE and hit enter.  After SMIT went through it's
configuration process I tired to talk to another host and it worked! 

CAn someone explain to me why I had to reconfigure TCP/IP to get the
communications working even though everything was set as it had been??  
Is there a quicker way to accomplish the same goal and ,most importantly,
how can I prevent this problem from re-occuring?

The macomputer in question is an RS/6000 320 with Aix V3.1 with the 3005
patches.


Thanks.


Shawn Hayes


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