Date: Mon, 17 Jan 2000 21:45:28 +0900 (YAKT) From: Maxim Konovalov <maxim@amur.cbr.ru> To: net@freebsd.org Subject: arp behaviour question Message-ID: <Pine.BSF.4.10.10001172119520.462-100000@noname.cbr.amur.ru>
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Hello Gentlemen, I have got a device, probably broken or incorrect configured, who replies twice to arp request "who-has". Well, let me show: # hostname -s stone # uname -v FreeBSD 3.4-STABLE #5: Fri Dec 31 12:32:11 XXXX 1999 maxim@stone.xxx.xxx.xxx:/usr/src/sys/compile/STONE # host mm1 mm1.xxx.xxx.xxx has address xxx.xxx.xxx.6 # arp -d mm1 delete: can't locate mm1 # arp mm1 mm1 (xxx.xxx.xxx.6) -- no entry # ping mm1 PING mm1.xxx.xxx.xxx (xxx.xxx.xxx.6): 56 data bytes 64 bytes from 10.82.64.6: icmp_seq=0 ttl=255 time=3.437 ms <---------------------------- at this point it stops reply ^C --- mm1.xxx.xxx.xxx ping statistics --- 9 packets transmitted, 1 packets received, 88% packet loss round-trip min/avg/max/stddev = 3.522/3.522/3.522/0.000 ms # arp mm1 mm1.xxx.xxx.xxx (xxx.xxx.xxx.6) at 0:0:1d:a0:8b:62 [ethernet] # On another terminal I run tcpdump: # tcpdump -i xl0 arp tcpdump: listening on xl0 10:20:12.658827 arp who-has mm1.xxx.xxx.xxx tell stone 10:20:12.659855 arp reply mm1.xxx.xxx.xxx is-at 0:0:1d:a0:8b:61 10:20:12.662712 arp reply mm1.xxx.xxx.xxx is-at 0:0:1d:a0:8b:62 You see, mm1 replies twice but it uses the first MAC in icmp echo-reply so if we take the second one we can't ping mm1. I found that Cisco IOS 10.2(8a) as well as Windows 98 behaves as FreeBSD. They take the second MAC and stop pinging after the second arp reply. But Linux RedHat 6.1 and Solaris 2.6 differs - they have got in their arp table the first MAC and can ping mm1. The question is: which behaviour is correct and why - FreeBSD or Solaris one? [ Yes, I have already read arp(4) and rfc826 ] Thank you for your help, Maxim Konovalov To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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