freebsd stable - Jan 2009 - IPv6 routing on 7.1R

Hi,

 I noticed an odd behavior regarding IPv6 after upgrading my 7.0R box
 to 7.1R.  The situation and symptom are the following:

 1. The box has two NICs.  One has an address 2001:0db8:1::1/64 (NIC
    A), and another has 2001:0db8:2::1/64 (NIC B).  These addresses
    are assigned manually ($ipv6_ifconfig in rc.conf).

 2. RA is periodically sent to the network 2001:0db8:1::1/64 (NIC A)
    by a router on the subnet.  The RA includes a source link-layer
    address option only.

 When setting net.inet6.ip6.accept_rtadv=1 in this configuration, I
 expected the box assigns an autoconf IPv6 address (prefix
 2001:0db8:1::/64 + EUI64) to NIC A and an default route based on
 source link-layer address in the RA packet.  Actually, these two were
 done as expected.  However, after addresses are assigned, routes for
 NIC B disappeared from the routing table.  More specifically, a
 cloning route "2001:0db8:2::1/64 -> link#2" was removed for some
 reason.

 Is this an expected behavior?  IIRC, 7.0R does not remove the route
 and I think it is strange.  It works fine if a box has a single NIC,
 though.

--
| Hiroki SATO
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On Mon, 12 Jan 2009, Hiroki Sato wrote:

Hi,
> I noticed an odd behavior regarding IPv6 after upgrading my 7.0R box
> to 7.1R.  The situation and symptom are the following:
>
> 1. The box has two NICs.  One has an address 2001:0db8:1::1/64 (NIC
>    A), and another has 2001:0db8:2::1/64 (NIC B).  These addresses
>    are assigned manually ($ipv6_ifconfig in rc.conf).
>
> 2. RA is periodically sent to the network 2001:0db8:1::1/64 (NIC A)
>    by a router on the subnet.  The RA includes a source link-layer
>    address option only.
>
> When setting net.inet6.ip6.accept_rtadv=1 in this configuration, I
> expected the box assigns an autoconf IPv6 address (prefix
> 2001:0db8:1::/64 + EUI64) to NIC A and an default route based on
> source link-layer address in the RA packet.  Actually, these two were
> done as expected.  However, after addresses are assigned, routes for
> NIC B disappeared from the routing table.  More specifically, a
> cloning route "2001:0db8:2::1/64 -> link#2" was removed for
some
> reason.
>
> Is this an expected behavior?
I don't think so. Can you file a PR and get it assigned to bz@ and
I'll look in two weeks or so once I am fully back.

/bz

-- 
Bjoern A. Zeeb                      The greatest risk is not taking one.