Path: utzoo!utgpu!attcan!uunet!lll-winken!ames!pasteur!ucbvax!BRL.MIL!tcs
From: tcs@BRL.MIL (Terry Slattery, SECAD)
Newsgroups: comp.protocols.tcp-ip
Subject: PSN weirdness
Message-ID: <8901111723.aa16077@SPARK.BRL.MIL>
Date: 11 Jan 89 22:23:03 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 30

Hi,
We've just seen some very strange behavior from some PSNs on the milnet and
would like some suggestions on how to proceed from here.

Synopsis:
	BRL internal hosts have been able to to talk to ARDEC.ARMY.MIL
(ARDEC.ARPA, addr 26.1.0.45) in the past.  However, for the last week or so,
the connections to them have been horrible to this site.  We can ping
26.0.0.45 (a TAC) with good turn-around times (< 500ms), but cannot ping
ardec at all.  The only other host on that PSN that we can contact is
TCACCIS-BAY.ARPA (26.2.0.45, also < 500ms). Testing from other milnet hosts
(usna.mil) shows that they can reach ardec, but that the round trip times
are vary quite widely (500ms - 5 sec).  Pings to the two working node 45
hosts also exhibit a long round trip time for the first few packets and then
stabilize at < 500ms.  Pings to other hosts around the milnet show no such
behavior.  Routes from both BRL-GATEWAY and USNA are identical.  Ardec can
occasionally reach BRL hosts, but we can not reach them.  In the recent
past, we have had problems maintaining connections to them.  Host
connections via other PSNs are fine.  

Could there be a PSN or line problem which would cause this type of
behavior?  Talking to the Milnet CONUS NOC was fruitless ("Maybe your
terminals are incompatible; your machine is running UTX and they are
running BSD.")  Milnet NOC was able to telnet to both hosts so they claim
the problem is with one of us (also suggesting that we checking host
tables, etc.)

Anyone have any suggestions?

	-tcs