[Babel-users] rib out of sync

[Dave Taht]

I have definitively proven that on at least one of the arm boxes we
are using (the getchip) that there is either a new babel bug in git,
and/or arm related issue with forming the netlink message, or a kernel
bug, or excessive gamma radiation in the atmosphere.

I am going to step back to 1.6.1 and see what happens there, and also
drop the arm boxes out of the equation, and hammer on x86, also, and
reduce or increase the number of routes babel is carrying.

I managed to duplicate all the weird behaviors I've seen over the past
several months by buckling down and simplifying things and just
looking at ipv6, while repeatedly failing and restoring an interface
(ifconfig down/up), and rebooting a lot... In particular, seeing the
asymmetric routing scenario take place, repeatably, gave much insight.

...

A feature request for babel one day is: to have a "Verify that the
kernel rib matches babel's rib" option.

...

dumping the babel routes (I do have a ton of routes (about 60
installed in a "working" kernel route table)), selecting 2 for the
sake of example:

fd99::13/128 from ::/0 metric 352 (357) refmetric 256 id
02:0d:b9:ff:fe:41:6c:2c seqno 60577 chan (255) age 16 via usb0 neigh
fe80::f0ba:5eff:feca:7f4e (installed)
fd99::13/128 from ::/0 metric 494 (525) refmetric 96 id
02:0d:b9:ff:fe:41:6c:2c seqno 60577 chan (36) age 7 via wlan0 neigh
fe80::100d:7fff:fe64:c990 (feasible)
^C

root at chipper:~# ip -6 route | grep usb
fe80::/64 dev usb0  proto kernel  metric 256

nothing else. That was last night. Same box, this morning...

root at chipper:~# ip -6 route | grep usb
fd99::4 via fe80::f0ba:5eff:feca:7f4e dev usb0  proto babel  metric 1024
fd9f:237b:c8a6::1d1 via fe80::f0ba:5eff:feca:7f4e dev usb0  proto
babel  metric 1024
fd9f:237b:c8a6:0:cca0:3c4a:60df:a69 via fe80::f0ba:5eff:feca:7f4e dev
usb0  proto babel  metric 1024
fd9f:237b:c8a6::/48 via fe80::f0ba:5eff:feca:7f4e dev usb0  proto
babel  metric 1024
fe80::/64 dev usb0  proto kernel  metric 256

(out of about 30 more that babel's rib claims is on this interface)

In terms of other issues, all in one log...

A) As for why all these routes are stored unreachable in this sample, dunno
B) refmetric 0?

::/0 from 2001:558:6045:bd:3977:7182:7772:8b2b/128 metric 65535
(65535) refmetric 65535 id 16:cc:20:ff:fe:e5:64:c2 seqno 8764 chan
(6,36) age 4 via wlan0 neigh fe80::7ec7:9ff:fede:2bb5 (installed)
::/0 from 2001:558:6045:bd:3977:7182:7772:8b2b/128 metric 640 (645)
refmetric 256 id 16:cc:20:ff:fe:e5:64:c2 seqno 8764 chan (36) age 4
via wlan0 neigh fe80::100d:7fff:fe64:c990 (feasible)
::/0 from 2001:558:6045:bd:3977:7182:7772:8b2b/128 metric 96 (101)
refmetric 0 id 16:cc:20:ff:fe:e5:64:c2 seqno 8764 age 6 via usb0 neigh
fe80::f0ba:5eff:feca:7f4e (feasible)
::/0 from 2001:558:6045:bd:3977:7182:7772:8b2b/128 metric 65535
(65535) refmetric 65535 id 16:cc:20:ff:fe:e5:64:c2 seqno 8764 chan
(6,36) age 5 via wlan0 neigh fe80::7ec7:9ff:fede:2bb5 (installed)
::/0 from 2001:558:6045:bd:3977:7182:7772:8b2b/128 metric 640 (645)
refmetric 256 id 16:cc:20:ff:fe:e5:64:c2 seqno 8764 chan (36) age 5
via wlan0 neigh fe80::100d:7fff:fe64:c990 (feasible)
::/0 from 2001:558:6045:bd:3977:7182:7772:8b2b/128 metric 96 (101)
refmetric 0 id 16:cc:20:ff:fe:e5:64:c2 seqno 8764 age 7 via usb0 neigh
fe80::f0ba:5eff:feca:7f4e (feasible)





-- 
Dave Täht
Let's go make home routers and wifi faster! With better software!
http://blog.cerowrt.org