Jail IPv6 only works after base initiates connection

[Farhan Khan]

Hi all,
When I start the jail, I get this message on my console.

nd6_dad_timer: cancel DAD on epair1b because of ND6_IFF_IFDISABLED.

Then the jail cannot use IPv6 until the base initiates connection to it (ie, the base pings the jail first). Otherwise, networking over IPv6 does not work
Any ideas? My /etc/jail.conf is below.

exec.start = "/bin/sh /etc/rc";
exec.stop = "/bin/sh /etc/rc.shutdown";
exec.clean;
$jailroot = "/jail";

smtp {
    host.hostname = "smtp.myhost";
    path = "${jailroot}/smtp";
    $if        = "1";
    $ip_addr    = "172.16.0.2";
    vnet;
    vnet.interface      = "epair${if}b";
    exec.prestart       = "ifconfig epair${if} create up";
    exec.prestart      += "ifconfig bridge0 addm epair${if}a";
    exec.start        = "/sbin/ifconfig epair${if}b inet ${ip_addr} up";
    exec.start       += "/sbin/route add default -gateway 172.16.0.1";
    exec.start       += "/bin/sh /etc/rc";
    exec.stop        = "/bin/sh /etc/rc.shutdown";
    exec.poststop        = "ifconfig epair${if}a destroy";

    devfs_ruleset        = "4";
    mount.devfs;

    persist;
}

Thanks