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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!simtel!zombie.ncsc.mil!news.mathworks.com!uhog.mit.edu!bloom-beacon.mit.edu!crl.dec.com!crl.dec.com!nntpd.lkg.dec.com!lkg.dec.com!thomas From: thomas@lkg.dec.com (Matt Thomas) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: very high collisions on FreeBSD machine Date: 22 Aug 1995 13:03:37 GMT Organization: Digital Equipment Corporation Lines: 32 Sender: thomas@netrix.lkg.dec.com (Matt Thomas) Distribution: world Message-ID: <41ckj9$vle@nntpd.lkg.dec.com> References: <ortegaDDpIpG.8Mu@netcom.com> Reply-To: thomas@lkg.dec.com NNTP-Posting-Host: netrix.enet.dec.com X-Newsreader: mxrn 6.18-30 In article <ortegaDDpIpG.8Mu@netcom.com>, ortega@netcom.com (John Ortega) writes: |>On a medium duty network (most machines show low collision rates) we have |>a genuine AMI P90 motherboard with 32M ram, 512K cache, 1 NCR scsi, 1 |>adaptec 2940 scsi, and 1 PCI DEC nic. This machine works qite well, but |>for the high collision rates it gets. A current netstat -ia showed: |> |>ipkts ierrs opkts oers coll |>883328843 280 34264945 0 10754790 |> |>Could this be software, are must it be hardware (I am not sure if |>software can have any thing to do with collisions) ? That can be quite normal. The DC21040 can start transmits right after the minimum inter-frame gap (as can many other chips) so it's more likely to collide than older chips (such as the LANCE) which could not switch from receive to transmit as quickly. (because of that, the LANCE would defer that packet since the Ethernet was already busy). Also note that the DC21040 also returns the count of collisions (which the driver adds to collisions; many other driver don't have that and so add 1 for a single collison and 2 for a multiple collision; the DC21040 driver will add 1..15 depending on the number which may make the values seem high). So unless you have a performance problem, the collision can be safely ignored. -- Matt Thomas Internet: thomas@lkg.dec.com U*X Networking WWW URL: http://ftp.dec.com/%7Ethomas/ Digital Equipment Corporation Disclaimer: This message reflects my Littleton, MA own warped views, etc.