Problems with IPv6 CARP Interface in PF

Michael K. Smith - Adhost mksmith at
Thu May 28 00:44:43 UTC 2009


I'm having reachability problems with a CARP interface set up on two 7.1
boxes with an uplink to Cisco routers.  However, the inside CARP address
on the same set of PF boxes are reachable with no trouble.  Here's the

Cisco 		Cisco
       HSRP Gateway
       CARP Interface 1
PF Box               PF Box
       CARP Interface 2

When I try to ping CARP Interface 1 above from the Internet, I get no
response.  When I ping the CARP Interface 2, which has a route set from
the Cisco's to CARP Interface 1, it works.  Here's what I see in my

00:38:45.763975 IP6 fe80::203:6cff:fef9:2c00 > ff02::1:ff00:7: ICMP6,
neighbor solicitation, who has 2001:4970:cccc::7, length 32

... with no response.

Here is the ifconfig from one box.

carp0: flags=49<UP,LOOPBACK,RUNNING> metric 0 mtu 1500
        inet6 2001:4970:cccc::6 prefixlen 64
        inet6 2001:4970:cccc::7 prefixlen 64
        carp: MASTER vhid 1 advbase 1 advskew 100
carp1: flags=49<UP,LOOPBACK,RUNNING> metric 0 mtu 1500
        inet6 2001:4970:cccc:aaaa::1 prefixlen 64
        carp: MASTER vhid 2 advbase 1 advskew 100

and the other shows appropriately as "BACKUP".  There is no change if I
run with just one PF box.

Any help would be greatly appreciated.


Michael K. Smith - CISSP, GISP
Chief Technical Officer - Adhost Internet LLC mksmith at
w: +1 (206) 404-9500 f: +1 (206) 404-9050
PGP: B49A DDF5 8611 27F3  08B9 84BB E61E 38C0 (Key ID: 0x9A96777D)

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