Kernel out of buffers

[David Melman]

We have a ethernet with many different machines running various versions of
Unix and other operating systems.  Our host, a Vax 785 running 4.3BSD with
original TCP/IP code, usually communicates with the net without problems.

However recently, with random occurances (from once a week to three
times a day), a situation arises where every attempt to access the net
results in a failure with the message: "No buffer space available".

When this situation occurs, the machine is completely cut off to the net and
is cleared only by a reboot.  This has occurred on other hosts running 4.3BSD
and Mt. XINU on the lan as well.  Interestingly enough, a 'netstat -m'
shows there are plenty of mbufs available.  What is happening?

Thanks in advance for suggestions to overcome this problem.

David
melman at technunix.BITNET