BGP Routing problem... your opinion

RouterOS General
1

There is a network which is, a mixture of linux & mikrotik routers.
Most of mikrotik routers are upper than 2.9.12 and less than 2.9.23.
Mostly without routing-test package.

Today we noticed this trace inside the network. It was the most tricky
off all we have seen…

We used to see loops but not as this

root@peggyzina:~# traceroute 10.37.57.252
traceroute to 10.37.57.252 (10.37.57.252), 30 hops max, 38 byte packets
1 hermes (10.86.87.139) 0.367 ms 0.136 ms 0.312 ms
2 gw-xrisoula.digi.awmn (10.86.87.118) 1.697 ms 1.911 ms 0.922 ms
3 gw-digi.selete.awmn (10.19.147.241) 1.902 ms 3.320 ms 1.930 ms
4 gw-selete.skilla.awmn (10.19.146.249) 4.600 ms 3.579 ms 2.715 ms
5 gw-xtreme.apoikos.awmn (10.19.141.35) 4.069 ms 4.924 ms 9.715 ms
6 gw-eaggelidis.xtreme.awmn (10.19.141.17) 5.241 ms 12.517 ms 15.808 ms
7 gw-xtreme.jchr.awmn (10.19.141.90) 27.974 ms 18.654 ms 17.147 ms
8 gw-jchr.RF.awmn (10.14.148.226) 10.335 ms 8.493 ms 11.571 ms
9 gw-RF.nvak.awmn (10.14.145.161) 12.223 ms 28.815 ms 11.092 ms
10 gw-ayis.bliz.awmn (10.2.13.121) 19.888 ms 18.415 ms 24.638 ms
11 gw-ayis.ysam2.awmn (10.19.143.26) 17.667 ms 15.097 ms 16.040 ms
12 gw-xtreme.ysam2.awmn (10.19.141.162) 20.768 ms 23.113 ms 18.236 ms
13 gw-eaggelidis.xtreme.awmn (10.19.141.17) 19.044 ms 39.191 ms 53.302 ms
14 gw-xtreme.jchr.awmn (10.19.141.90) 29.482 ms 25.466 ms 29.131 ms
15 gw-jchr.RF.awmn (10.14.148.226) 32.348 ms 36.111 ms 41.690 ms
16 gw-RF.nvak.awmn (10.14.145.161) 63.764 ms 31.750 ms 83.393 ms
17 gw-ayis.bliz.awmn (10.2.13.121) 24.829 ms 61.230 ms 48.279 ms
18 gw-ayis.ysam2.awmn (10.19.143.26) 61.055 ms 77.592 ms 24.110 ms

many hours before this trace, we had this from a sh ip bgp

4371 3460 6631 4422 3473 92 616 413 2581 1084 2435 2125 633 3929 1966 38 6840 1702 1064 2720 4492 6674 4 4263 4272 7603 > 3451 1265 23 > > 3451 1265 23 > 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 1265 23 3451 2339 4343 1790 23 3451 1265 23 3451 1265 > 23 3451 1265 > > 23 3451 1265 > 405 23 3451 3210 123 1286 45 2801 3170 3180 410 4097 806 3267 4381 5013

we are really confused about the way, that bgp decides which
path is best for the desired destination and the reason that
creates these huge loops.

2

would it be possible to create a kind, of debugging utilities for networking
and mostly for dynamic routing ?

do you have something in mind, like, vtysh> sh ip bgp (which is totaly
different from sh>ip route or sh>route) ?

when we have to work with common As, the comparison of these two tables
is very helpfull, since kernel may not have routes, when bgp should.

your suggestion on this issue ?

3

like i said before:

their OWN review for BGP (without many VTY quagga features - like commands in cisco).
Dont expect anything from Mikrotik people, im in trouble with BGP too.
And i see in documentation they no have examples for correct configured bgp for single or multi homed router working with something different (cisco, juniper, REAL quagga, zebra).
Finaly:
we are international testing lab :slight_smile: