Date: Mon, 14 Dec 2009 14:59:34 -0800 From: "Li, Qing" <qing.li@bluecoat.com> To: "Dennis Glatting" <freebsd@penx.com>, "JASSAL Aman" <aman.jassal@esigetel.fr> Cc: freebsd-net@freebsd.org Subject: RE: Understanding multiple IPv6 interfaces under 8.0 (fwd) Message-ID: <B583FBF374231F4A89607B4D08578A4304673758@bcs-mail03.internal.cacheflow.com> References: <alpine.BSF.2.00.0912131456440.83238@Elmer.dco.penx.com><9223.83.206.131.26.1260781902.squirrel@webmail.esigetel.fr> <alpine.BSF.2.00.0912141451480.16515@Elmer.dco.penx.com>
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You don't need to perform all that route-foo. I believe the root cause =
of
this issue may be due to a bit of regression in the IPv6 prefix =
management
code, and I am in the process of putting together a permanent fix.
The issue as it stands today, is due to how the prefix was inserted in
the first place. Since bce0 was configured first, the interface =
associated
with the prefix is bce0. Later the reference count on the prefix is
simply incremented when bce1 configures another IPv6 address of the=20
same prefix.=20
When ND6 NS arrives for bce1, due to the interface mismatch of the =
prefix
interface against the input interface, the NS packet was considered
invalid and thus dropped.
Again, in case you didn't see my earlier reply, try the temporary hack =
at
http://people.freebsd.org/~qingli/nd6-ns.diff=20
until I commit a permanent patch. The problem was easily reproducible =
and=20
I have verified with limited unit testing the patch works.
-- Qing
-----Original Message-----
From: owner-freebsd-net@freebsd.org on behalf of Dennis Glatting
Sent: Mon 12/14/2009 2:03 PM
To: JASSAL Aman
Cc: freebsd-net@freebsd.org
Subject: Re: Understanding multiple IPv6 interfaces under 8.0 (fwd)
=20
Thanks. Responses in-line.
On Mon, 14 Dec 2009, JASSAL Aman wrote:
> Hello Mr.Glatting,
>
> Not that I'm an IPv6 genius, but at first sight your problem seems to =
be a
> route-related. I've put comments in-line.
>
>
> Le Dim 13 d?cembre 2009 22:58, Dennis Glatting a ?crit :
>>
>>
>> Elmer# netstat -rn
>> Routing tables
>>
>>
>> Internet6:
>> Destination Gateway Flags
>> Netif Expire
>> ::/96 ::1 UGRS
>> lo0 =3D> default fd7c:3f2b:e791:1::1
>> UGS bce0
>> ::1 ::1 UH
>> lo0 ::ffff:0.0.0.0/96 ::1 =
UGRS
>> lo0 fd7c:3f2b:e791:1::/64 link#1 U
>> bce0 fd7c:3f2b:e791:1::ac13:a0a link#1 =
UHS
>> lo0 fd7c:3f2b:e791:1:0:1:ac13:a0a link#2 =
UHS
>> lo0 fe80::/10 ::1 =
UGRS
>> lo0 fe80::%bce0/64 link#1 U
>> bce0 fe80::213:72ff:fe60:ac52%bce0 link#1 =
UHS
>> lo0 fe80::%bce1/64 link#2 U
>> bce1 fe80::213:72ff:fe60:ac50%bce1 link#2 =
UHS
>> lo0 fe80::%lo0/64 link#3 U
>> lo0 fe80::1%lo0 link#3 =
UHS
>> lo0 ff01:1::/32 fe80::213:72ff:fe60:ac52%bce0 U
>> bce0 ff01:2::/32 fd7c:3f2b:e791:1:0:1:ac13:a0a =
U
>> bce1 ff01:3::/32 ::1 =
U
>> lo0 ff02::/16 ::1 =
UGRS
>> lo0 ff02::%bce0/32 fe80::213:72ff:fe60:ac52%bce0 U
>> bce0 ff02::%bce1/32 fd7c:3f2b:e791:1:0:1:ac13:a0a =
U
>> bce1 ff02::%lo0/32 ::1 =
U
>> lo0
>>
>
> Hmm, the entry for fd7c:3f2b:e791:1:0:1:ac13:a0a looks suspect. I was=20
> expecting bce1 rather than lo0, I suppose you were as well :) If I'm =
not=20
> mistaken, the packets emanating from bce1 go to the loopback =
interface,=20
> thus not really going out. You can try specifying the route manually=20
> with "route add *your parameters*" or even set it in /etc/rc.conf so=20
> that it's loaded at boot-time. There's no reason why among 2 physical=20
> interfaces sharing the same fabric, one can ship packets out and the=20
> other can't.
>
I was wondering about the route however I haven't figured out the trick =
to=20
get what I want. For example:
Elmer# route delete -inet6 fd7c:3f2b:e791:1:0:1:ac13:a0a
delete host fd7c:3f2b:e791:1:0:1:ac13:a0a
Elmer# route add=20
-inet6 fd7c:3f2b:e791:1:0:1:ac13:a0a/64 -iface bce1
route: writing to routing socket: File exists
add net fd7c:3f2b:e791:1:0:1:ac13:a0a/64: gateway bce1: route already in =
table
I did delete the lo0 route before I exected the above command. Also, I=20
haven't been able to specify a higher metric (e.g., -metric 2). That is=20
rejected too. However, I can say:
Elmer# route delete -inet6 fd7c:3f2b:e791:1:0:1:ac13:a0a
delete host fd7c:3f2b:e791:1:0:1:ac13:a0a
Elmer# route add -inet6 fd7c:3f2b:e791:1:0:1:ac13:a0a -iface bce1
add host fd7c:3f2b:e791:1:0:1:ac13:a0a: gateway bce1
Elmer# netstat -rn
(snip)
fd7c:3f2b:e791:1:0:1:ac13:a0a 00:13:72:60:ac:50 UHS =
bce1
I don't think that is what I want. WHat I think I just said is "host X" =
is=20
out that door, rather than route net. If, however, I say Docs is out =
that=20
door, I get:
Elmer# route add -inet6 docs.dco.penx.com -iface bce1
add host docs.dco.penx.com: gateway bce1
Elmer# ping6=20
docs.penx.com
PING6(56=3D40+8+8 bytes) fd7c:3f2b:e791:1:0:1:ac13:a0a --> =
fd7c:3f2b:e791:1::ac13:a15
ping6: sendmsg: Operation not permitted
ping6: wrote docs.dco.penx.com 16 chars, ret=3D-1
>>
>> Elmer's rc.config:
>>
>>
>> ipv6_enable=3D"YES" ipv6_network_interfaces=3D"bce0 bce1"
>> ipv6_ifconfig_bce0=3D"FD7C:3F2B:E791:0001::0:172.19.10.10 prefixlen =
64"
>> ipv6_ifconfig_bce1=3D"FD7C:3F2B:E791:0001::1:172.19.10.10 prefixlen =
64 mtu
>> 8192"
>> ipv6_defaultrouter=3D"FD7C:3F2B:E791:0001::1"
>>
>
> Erm... You're using IPv4 addresses encapsulated in IPv6 ? I've never =
used
> this myself so I can't really comment, and I can't say if there aren't =
any
> sort of "interferences" with what you're trying to do.
>
I hope what I am specifying is to use the 32 bit IPv4 address as the =
last=20
32 bits of the IPv6 address, at least that is how it works out=20
numerically. My numbering scheme for fixed assets is the last 32 bits of =
the 128 bit IPv6 address is the same as its IPv4 address.
>>
>>
>> The router (cisco):
>>
>>
>> interface GigabitEthernet0/0 ipv6 address FD7C:3F2B:E791:1::1/64 ipv6
>> enable ipv6 nd prefix FD7C:3F2B:E791:1::/64 (etc)
>>
>
> Just a side-note, I'm not sure if it will be really useful to you, but =
you
> could give it a try if you want to. Have you tried using your Cisco =
router
> as a Router Advertisement Daemon ? That way, addresses would be built
> automatically and you could see how both interfaces react to such
> advertisements.
>
> I hope this helps.
>
> ------------
> Aman Jassal
>
> Wisdom comes from experience.
> Experience comes from a lack of wisdom.
>
>
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