Article View: comp.dcom.sys.cisco
Article #392KeepAlives and half duplex failures
From: Jerry Aguirre
Date: Tue, 10 Apr 1990 10:29
Date: Tue, 10 Apr 1990 10:29
20 lines
1333 bytes
1333 bytes
Let me preface this by stating that this is a request for information and I don't know this to be a problem but.... It seems to me that keepalives do exactly the wrong thing when one half of a line fails. Given that most lines are full duplex it is quite reasonable for one direction to fail while the other continues to operate. Assume that the line from A to B is working but the reverse direction has a problem. B will continue to receive keepalives and, worse, routing information from A. But when it tries to use that line to B the packet gets dropped on the floor. Meanwhile A has a potentially good path to B but won't use it for lack of keepalives and routing updates. I think I observed this happening while debugging a line. Is this how it really works or are keepalives smarter than that? Does the keepalive packet contain information about whether the sender has been receiving keepalives on that line? Jerry Aguirre
Technical Details
Message-ID:
<19499@boulder.Colorado.EDU>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!sunybcs!boulder!daemonShow Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!sunybcs!boulder!daemon From: jerry@OLIVEY.ATC.OLIVETTI.COM (Jerry Aguirre) Newsgroups: comp.dcom.sys.cisco Subject: KeepAlives and half duplex failures Message-ID: <19499@boulder.Colorado.EDU> Date: 10 Apr 90 10:29:41 GMT Sender: daemon@boulder.Colorado.EDU Lines: 20