From owner-freebsd-hackers Tue May 16 12:35:30 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id MAA18371 for hackers-outgoing; Tue, 16 May 1995 12:35:30 -0700 Received: from alpha.xerox.com (alpha.Xerox.COM [13.1.64.93]) by freefall.cdrom.com (8.6.10/8.6.6) with SMTP id MAA18365 for ; Tue, 16 May 1995 12:35:29 -0700 Received: from crevenia.parc.xerox.com ([13.2.116.11]) by alpha.xerox.com with SMTP id <14483(6)>; Tue, 16 May 1995 12:34:36 PDT Received: from localhost by crevenia.parc.xerox.com with SMTP id <49859>; Tue, 16 May 1995 12:34:24 -0700 X-Mailer: exmh version 1.6 4/21/95 To: Thomas Graichen cc: freebsd-hackers@FreeBSD.org Subject: Re: "arp info overwritten" problem In-reply-to: Your message of "Tue, 16 May 95 07:22:44 PDT." <9505161422.AA16140@sirius.physik.fu-berlin.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 16 May 1995 12:34:08 PDT From: Bill Fenner Message-Id: <95May16.123424pdt.49859@crevenia.parc.xerox.com> Sender: hackers-owner@FreeBSD.org Precedence: bulk In message <9505161422.AA16140@sirius.physik.fu-berlin.de> you write: >here i often get the "arp info overwritten for 130.133.255.255 from ..." - >aroud every 1/4 i get this and i think it's because FreeBSD keeps the >broadcast adress in his arp cache -> arp -a looks like: > >graichen@julia:~> arp -a >BROADCAST.fu-berlin.de (130.133.255.255) at 8:0:14:15:16:78 This is, of course, not the broadcast MAC address; it is the address of a device with an ethernet card manufactured by Excelan, which could be a BBN Butterfly, Masscomp, Silicon Graphics, or other. FreeBSD doesn't use the ARP table for broadcasts; arpresolve() is hardwired to return the ethernet broadcast address when it gets passed a broadcast mbuf. My only guess as to what is going on is that someone is sending a broadcasted arp reply for the broadcast address, or something bizarre like that. The only way to know for sure is to use tcpdump (try "tcpdump -v -e -n arp") and see if you ever see a line that says something like "arp reply 130.133.255.255 is-at 8:0:14:15:16:78". (p.s. what is your netmask and broadcast address on that interface?) Bill