[4407] in Athena Bugs
tcp bug in dialup server kernels
daemon@ATHENA.MIT.EDU (hoffmann@MIT.EDU)
Mon Mar 5 10:21:03 1990
From: hoffmann@MIT.EDU
Date: Mon, 5 Mar 90 10:20:25 EST
To: jfc@ATHENA.MIT.EDU
Cc: roden@ATHENA.MIT.EDU, bug-new-dialup@ATHENA.MIT.EDU, bugs@ATHENA.MIT.EDU
John, this bug was likely the reason the 18.71 router
crashed yesterday. The symptoms were similar to ones
we have seen in the past with the SIPB dialups before a
TCP bug was quashed.
Scenario is that a PC in the Sloan school makes an ftp
connection to the dialup server and for some reason
negotiates an MSS of 0. The dialup server believes this
for some reason and then goes into a tight loop sending
micro-datagrams back at the pc, completely saturating
the router.
I think that applying that patch to the dialup server
kernels needs to be a top priority right now since we
can't stand to have outages like that on any kind of basis.
Someone (bugs) should verify that this patch has made it into
the master sources or we'll have this happening all over
the Institute!
-Ron
