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From: hedrick@cs.rutgers.edu
Newsgroups: comp.dcom.sys.cisco
Subject: Re:  KeepAlives and half duplex failures
Message-ID: <19502@boulder.Colorado.EDU>
Date: 10 Apr 90 11:51:34 GMT
Sender: daemon@boulder.Colorado.EDU
Lines: 8

keepalives on a serial line exchange serial numbers in both
directions.  That is, both ends send a number and echo back what they
see from the other end.  Protocol up means that the copy of the serial
number echoed back from the other end is up to date.  So it has to
mean that both ends are sending and receiving keepalives correctly.
We do in fact see keepalive failing at the same time on both ends.
I suppose keepalive is enabled on both ends with the same time
constant?