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Newsgroups: comp.os.386bsd.bugs Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!saimiri.primate.wisc.edu!caen!destroyer!cs.ubc.ca!unixg.ubc.ca!kakwa.ucs.ualberta.ca!acs.ucalgary.ca!cpsc.ucalgary.ca!xenlink!fsa.ca!deraadt From: deraadt@fsa.ca (Theo de Raadt) Subject: Re: Ping problem In-Reply-To: davidg@implode.rain.com's message of 9 May 93 13: 58:16 GMT Message-ID: <DERAADT.93May9153955@newt.fsa.ca> Sender: news@fsa.ca Nntp-Posting-Host: newt.fsa.ca Organization: little lizard city References: <C6rIt5.1wp@implode.rain.com> Date: Sun, 9 May 1993 22:39:55 GMT Lines: 27 In article <C6rIt5.1wp@implode.rain.com> davidg@implode.rain.com (David Greenman) writes: > inits this variable itself (hardcoded to 50). Another thing you could try > would be to increase the SLIP MTU. Note that because the MCLBYTES param > is normally 1024 bytes, that the MTU will never exceed this (in fact the > kernel will panic if the SLIP MTU is set to more than about 950). It is > likely that the interim release of 386BSD (0.1.5) will have this changed > to 2048. With it at 1024, even ethernet traffic is forced to use small > packets - in some cases fragmenting them to 1024 and 500 (approx). I would suggest you *NOT* increase the MTU on the slip interface. Myself, I run PPP with an MTU of 256 bytes. 1) Fragmentation of packets does not hurt that performance much, and 2) if it is increased, running an ftp and an rlogin at the same time will give TERRIBLE performance. With a smaller MTU, the rlogin/telnet priority mechanism gets more chances to reorder the outgoing packet queue such that rlogin/telnet packets get sent through before ftp packets. My opinion on this entire issue is "Who cares if ping fails". Because every other protocol that I can name knows how to deal with ENOBUFS and back off a bit (including nfs, if anyone here is insane enough to run nfs over a slip -- no hard checksums.) <tdr. -- This space not left unintentionally unblank. deraadt@fsa.ca