Mail and other weird upgrade related problems...

[Robert Dinse <nanook@eskimo.com>]

     Had some strange problems after the upgrade.

     A number of strange problems occured, most related to slow connections to
mail or connections timing out, but there were other spurious problems as well.
Looking at logs, I saw random name server failures, but testing our name
servers (from eskimo) didn't reveal any problems.  The mail machine itself
showed no signs of ill-health. 

     Finally (about 7am after being up all night), I re-arranged the name
servers that mail uses so that ns1.eskimo.com (which is a virtual interface on
eskimo presently) wasn't first, and then I could connect to it right away. 

     I tried pinging ns1 from mail and couldn't.

     I did an arp -a and noticed the ethernet address was incorrect.

     Well, I've run into this problem before where SunOS wants to hang on to
old arp entries after hardware is changed, and it's a real pain in a sizeable
network because you can get it cleared from one machine but another machine
with a bad entry will respond to an arp request with it's bad entry polluting
the arp table of a machine you just clearned out. 

     No matter what I did I couldn't get rid of this one bad entry, was driving
me crazy, even rebooted the switching hub and router thinking maybe they were
hanging onto it. 

     Then I found it was only hosed for the virtual interface, but not the main
address.  I looked at the initialization file for virtual interfaces and it was
hard-coded into the file.  Fixed that, rebooted, cleared all the bad entires,
and now everything appears to be back to normal.