Date: Wed, 24 Oct 2007 16:37:54 GMT From: Jacek Zapala <jacek@ipv6.jacek.it.pl> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/117456: ipv6 neighbour discovery / bce multicast problem Message-ID: <200710241637.l9OGbsIm017556@www.freebsd.org> Resent-Message-ID: <200710241640.l9OGe2vc060360@freefall.freebsd.org>
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>Number: 117456 >Category: kern >Synopsis: ipv6 neighbour discovery / bce multicast problem >Confidential: no >Severity: non-critical >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Oct 24 16:40:02 UTC 2007 >Closed-Date: >Last-Modified: >Originator: Jacek Zapala >Release: 6.2-RELEASE-p8 >Organization: >Environment: FreeBSD 6.2-RELEASE-p8 #0: Mon Oct 15 15:29:48 CEST 2007 root@server:/usr/src/sys/i386/compile/DELL_2950 i386 >Description: There are two FreeBSD-6.2 servers on the same subnet: A (2001:XXXX:YYYY:1::270) and B (2001:XXXX:YYYY:1::267) I try to ping6 B from A. B does not see neighbour discovery packets sent by A. It starts to see them just after enabling promiscuous mode on B. A:~# ifconfig bce0 bce0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 options=3b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU> inet6 fe80::21a:a0ff:fe0e:8990%bce0 prefixlen 64 scopeid 0x1 inet6 2001:XXXX:YYYY:1::270 prefixlen 120 inet6 2001:XXXX:YYYY:1::272 prefixlen 120 (inet4 addresses deleted) ether 00:1a:a0:0e:89:90 media: Ethernet autoselect (100baseTX <full-duplex>) status: active B:~# ifconfig bce0 bce0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 options=3b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU> inet6 fe80::21a:a0ff:fe34:e724%bce0 prefixlen 64 scopeid 0x1 inet6 2001:XXXX:YYYY:1::267 prefixlen 120 inet6 2001:XXXX:YYYY:1::269 prefixlen 120 (inet4 addresses deleted) ether 00:1a:a0:34:e7:24 media: Ethernet autoselect (100baseTX <full-duplex>) status: active B:~# netstat -ia Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll bce0 1500 <Link#1> 00:1a:a0:34:e7:24 398232 0 416485 0 0 33:33:ff:00:02:69 729 8 33:33:ff:00:02:67 729 8 01:00:5e:00:00:01 729 8 33:33:f2:4c:bf:48 729 8 33:33:00:00:00:01 729 8 33:33:ff:34:e7:24 729 8 Packets on the wire (sniffed on third machine): 16:06:55.584139 00:1a:a0:0e:89:90 > 33:33:ff:00:02:67, ethertype IPv6 (0x86dd), length 86: 2001:XXXX:YYYY:1::270 > ff02::1:ff00:267: ICMP6, neighbor solicitation, who has 2001:XXXX:YYYY:1::267, length 32 16:06:56.607487 00:1a:a0:0e:89:90 > 33:33:ff:00:02:67, ethertype IPv6 (0x86dd), length 86: 2001:XXXX:YYYY:1::270 > ff02::1:ff00:267: ICMP6, neighbor solicitation, who has 2001:XXXX:YYYY:1::267, length 32 B does not see them: B:~# tcpdump -n -p host 2001:XXXX:YYYY:1::270 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on bce0, link-type EN10MB (Ethernet), capture size 96 bytes ^C 0 packets captured 746805 packets received by filter 0 packets dropped by kernel Enabling promiscuous mode (no -p option) solves the problem: B:~# tcpdump -n host 2001:XXXX:YYYY:1::270 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on bce0, link-type EN10MB (Ethernet), capture size 96 bytes 16:46:11.348129 IP6 2001:XXXX:YYYY:1::270 > ff02::1:ff00:267: ICMP6, neighbor solicitation, who has 2001:XXXX:YYYY:1::267, length 32 16:46:11.348202 IP6 2001:XXXX:YYYY:1::267 > 2001:XXXX:YYYY:1::270: ICMP6, neighbor advertisement, tgt is 2001:XXXX:YYYY:1::267, length 32 16:46:11.348373 IP6 2001:XXXX:YYYY:1::270 > 2001:XXXX:YYYY:1::267: ICMP6, echo request, seq 258, length 16 16:46:11.348393 IP6 2001:XXXX:YYYY:1::267 > 2001:XXXX:YYYY:1::270: ICMP6, echo reply, seq 258, length 16 Do I miss something very obvious? I use pf, but pfctl -d does not help >How-To-Repeat: Well, boot a machine and try to ping6 it. I know it sounds like I'm drunk ;-) >Fix: >Release-Note: >Audit-Trail: >Unformatted:
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