kern/153848: [carp] [ipv6] backup host can't connect to master host

[Alexander Hausner]

>Number:         153848
>Category:       kern
>Synopsis:       [carp] [ipv6] backup host can't connect to master host
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Jan 10 14:10:12 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Alexander Hausner
>Release:        FreeBSD 8.2-PRERELEASE #0
>Organization:
BMG
>Environment:
FreeBSD fbsd2.bmg.gv.at 8.2-PRERELEASE FreeBSD 8.2-PRERELEASE #0: Wed Jan  5 17:56:25 CET 2011     root at fbsd1.bmg.gv.at:/usr/obj/usr/src/sys/GENERIC  amd64

>Description:
Hi,

in an ipv6 environment carp backup host can't connect to master host via ipv6. The backup host connects only to itself.

Given the following environment:

host fbsd1:

fbsd1# ifconfig
em0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
        ether 08:00:27:d2:e3:52
        inet 10.41.77.1 netmask 0xffff0000 broadcast 10.41.255.255
        inet6 fe80::a00:27ff:fed2:e352%em0 prefixlen 64 scopeid 0x1
        inet6 2b17::1 prefixlen 64
        nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
        media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
        options=3<RXCSUM,TXCSUM>
        inet 127.0.0.1 netmask 0xff000000
        inet6 ::1 prefixlen 128
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x2
        nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
carp0: flags=49<UP,LOOPBACK,RUNNING> metric 0 mtu 1500
        inet6 2b17::10 prefixlen 64
        nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
        carp: MASTER vhid 1 advbase 1 advskew 0

host fbsd2:

fbsd2# ifconfig
em0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
        ether 08:00:27:6d:e0:f9
        inet 10.41.77.2 netmask 0xffff0000 broadcast 10.41.255.255
        inet6 fe80::a00:27ff:fe6d:e0f9%em0 prefixlen 64 scopeid 0x1
        inet6 2b17::2 prefixlen 64
        nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
        media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
        options=3<RXCSUM,TXCSUM>
        inet 127.0.0.1 netmask 0xff000000
        inet6 ::1 prefixlen 128
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x2
        nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
carp0: flags=49<UP,LOOPBACK,RUNNING> metric 0 mtu 1500
        inet6 2b17::10 prefixlen 64
        nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
        carp: BACKUP vhid 1 advbase 1 advskew 100

if you try now a telnet to 2b17::10 port 25/tcp on host fbsd2 gives the following:

fbsd2# telnet 2b17::10 25
Trying 2b17::10...
Connected to 2b17::10.
Escape character is '^]'.
220 fbsd2.bmg.gv.at ESMTP Sendmail 8.14.4/8.14.4; Mon, 10 Jan 2011 15:48:11 +0100 (CET)

It connects to itself (backup host) not to the master host, the same thing with ipv4 works correctly as expected i.e. it connects to the master host.

Thanks in advance,

Alex
>How-To-Repeat:

>Fix:


>Release-Note:
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