[Babel-users] default route weirdness

[Dave Taht]

So I'm now at 4 out of 8 core-ish routers upgraded to openwrt 18.06,
with my first in 4+ years gateway router now online as of late last
night. I think there may be a problem in 1.8.x with 2 packets or...
with default routes. Or with mcast on this version of openwrt. or
something else.

packet cap: http://flent-fremont.bufferbloat.net/~d/weird/wtf.cap

* Topology:

apu2, nano C, nano D were 1.8.2, now 1.8.3 w my patches (and were
flaky also with 1.8.2, but I will back them out... but I'm going to
back off to 1.7.1 as that helped tim a week or so back )

C, D are 1.8.0, which I can fix next... they stay stuck on the multi-hop
default route with a high metric and only get the local one for a
brief time (perhaps only on the initial announcement or on a route
transfer request)

cerowrt box is 1.7.1

comcast <-> apu2 <-> switch <-> centralpark wifi AP1
                                    |       |
                               nano A  nano B
                                    |       |
                                nano C  nano D
                                   |        |
                                  old cerowrt box <-> comcast

so... This is the weird part - from wifi AP1. the a06d address
is the apu2... this default route has a really high metric, and vanishes
after a while...

add route 863e80 prefix 0.0.0.0/0 from ::/0 installed no id
a2:21:b7:ff:fe:ac:e4:55 metric 676 refmetric 580 via
fe80::20d:b9ff:fe43:a06d if eth0

and *all* the other routes it gets from the apu2 for that, including
the hello, are sane.

add route 862ca0 prefix 50.197.142.144/29 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 97 refmetric 1 via
fe80::20d:b9ff:fe43:a06d if eth0 # I added 1 just to see if this part
was working
add route 863df0 prefix 50.197.142.146/32 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0

add route 862d20 prefix 172.21.0.0/22 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0
add route 864f10 prefix 172.21.0.0/24 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0
add route 864dd0 prefix 172.21.0.1/32 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0
add route 864f90 prefix 172.21.2.0/24 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0
add route 864e50 prefix 172.21.2.1/32 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0
add route 864360 prefix 172.21.2.5/32 from ::/0 installed no id
02:27:22:ff:fe:b6:c9:14 metric 192 refmetric 96 via
fe80::20d:b9ff:fe43:a06d if eth0

then:

root at centralpark:~# echo dump | nc ::1 33123 | grep fe80::20d:b9ff:fe43:a06d
add neighbour 422af0 address fe80::20d:b9ff:fe43:a06d if eth0 reach
ffff rxcost 96 txcost 96 rtt 0.662 rttcost 0 cost 96
add route 862ca0 prefix 50.197.142.144/29 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 97 refmetric 1 via
fe80::20d:b9ff:fe43:a06d if eth0
add route 863df0 prefix 50.197.142.146/32 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0
add route 862d20 prefix 172.21.0.0/22 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0
add route 864f10 prefix 172.21.0.0/24 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0
add route 864dd0 prefix 172.21.0.1/32 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0
add route 864f90 prefix 172.21.2.0/24 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0
add route 864e50 prefix 172.21.2.1/32 from ::/0 installed yes id
02:0d:b9:ff:fe:43:a0:6c metric 96 refmetric 0 via
fe80::20d:b9ff:fe43:a06d if eth0

So I'll do things like restart the apu2 daemon, that default route
shows up for a while, but shows no metric evolution, then vanishes in
30+ seconds while all the other announced routes stay at metric 96.
I'm not fiddling with the metric on the default route
announcement.....

root at centralpark:~# echo dump | nc ::1 33123 | grep 0.0.0.0
add route 8642e0 prefix 0.0.0.0/0 from ::/0 installed yes id
a2:21:b7:ff:fe:ac:e4:55 metric 448 refmetric 352 via
fe80::227:22ff:feb7:c914 if eth0
add route 864c10 prefix 0.0.0.0/0 from ::/0 installed no id
a2:21:b7:ff:fe:ac:e4:55 metric 544 refmetric 448 via
fe80::20d:b9ff:fe43:a06d if eth0


-- 

Dave Täht
CEO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-669-226-2619