[Babel-users] Buggy routes exported by babeld

[Denis Ovsienko]

23.04.2013, 11:41, "Baptiste Jonglez" <baptiste.jonglez at ens-lyon.fr>:
> On Mon, Apr 22, 2013 at 10:29:22PM +0200, Gioacchino Mazzurco wrote:
>
>>  I can reproduce a similar but not identical bug because my filter are defferent
>>
>>  gioacchino at G10h4ckLab ~ $ ip -6 route show
>>  ...
>>  ...
>>  2001:470:c8f7:ee:ee:15:6d7b:4d21 via fe80::7825:ddff:fe9d:4643 dev isole  proto
>>  42  metric 1024
>>  2001:470:c8f7:ee:ee:15:6d7d:9e9 via fe80::7825:ddff:fe9d:4643 dev isole  proto
>>  42  metric 1024
>>  2001:470:c8f7:ee:7058:edab:5584:25b8 via fe80::7825:ddff:fe9d:4643 dev isole
>>  proto 42  metric 1024
>>  2001:470:c8f7:ee:f4e4:47dd:ac3a:f52d via fe80::7825:ddff:fe9d:4643 dev isole
>>  proto 42  metric 1024
>>  ...
>>  ...
>>
>>  those 3  /128 route shouldn't appear ( they aren't babel node but a babel node
>>  can see them ( but doesn't have a specifical 128 route for them ) )
>
> All right, it looks similar enough.
>
> The /128 routes I was talking about are the routes that babeld
> reportedly exports. Other babel nodes simply grab these exported buggy
> routes and install them in their routing table (as in your case).

My experience is as follows. A Linux (kernel 3.6.11-4.fc16.x86_64) PC with a single wireless interface runs both IPv4 and IPv6. It has a number of IPv6 neighbors visible with "ip -6 ne", which don't produce any extra IPv6 routes visible with "ip -6 ro". Pinging external IPv6 hosts, however, produces a few extra IPv6 routes like below:

2001:67c:2e8:22::c100:68b via fe80::215:17ff:fe6a:f1b0 dev wlan1  metric 0 
    cache 
2a00:1450:4010:c03::64 via fe80::215:17ff:fe6a:f1b0 dev wlan1  metric 0 
    cache 
2a00:1450:4010:c03::71 via fe80::215:17ff:fe6a:f1b0 dev wlan1  metric 0 
    cache 
2a00:1450:4010:c04::8b via fe80::215:17ff:fe6a:f1b0 dev wlan1  metric 0 
    cache 

(Note the "cache" keyword that is missing from the case above, but "proto 42" is present.)

Running the standalone babeld (current git master) as "./babeld wlan1" on the PC does not translate these cached routes into the Babel routing domain (there's tcpdump running to examine the contents of the PDUs). The only /128 route advertised is the address of the wlan1 interface itself. Running babeld as "./babeld -C "redistribute ip ::/0 metric 256" -d 2 wlan1" doesn't change anything either, except that the default route (::/0) is advertised.

-- 
    Denis Ovsienko