Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!mailrus!ukma!rutgers!elbereth.rutgers.edu!ron.rutgers.edu!ron From: ron@ron.rutgers.edu (Ron Natalie) Newsgroups: comp.protocols.tcp-ip Subject: Re: TCP implementations and FIN-WAIT-2 Message-ID: Date: 14 Dec 88 16:08:34 GMT References: <8812131807.AA06763@felix.xpiinc.uu.net> Organization: Rutgers Univ., New Brunswick, N.J. Lines: 15 You DO NOT want to just use a timer to kill FIN-WAIT-2 state connections after some period of inactivity. This kills applications that legitimately work this way, notably rsh. It's been tried in the past. I tend towards the Phil Karn approach, that this should be left to the application. An application should decide how long after it closes the transmit side of a connection it should wait before it gives up and forces the TCB to go away. If data arrives after that, it should get a RST, which is the proper action whenever data arrives for a connection that doesn't exist. Of course, I believe UNIX lacks the ability to do this properly in 4.3 (I don't know what Mike has done in 4.4 or has in mind for the future). A application probe call that throws packets at an already FIN-ed connection to see if it can awaken the other end, might be useful however. -Ron