Community discussions

 
elkdata
just joined
Topic Author
Posts: 3
Joined: Thu Apr 04, 2013 3:01 pm

BGP path selection

Thu Apr 04, 2013 3:14 pm

Hello!

I try to find out, why shorter AS path is not used.
We have CCR1016-12G, with 6.0rc11.
peer options:
     tcp-md5-key="" nexthop-choice=default multihop=no route-reflect=no hold-time=3m 
     ttl=default in-filter="" out-filter=as-elkdata-out address-families=ip,ipv6 
     default-originate=never remove-private-as=no as-override=no passive=no use-bfd=no
instance options:
      redistribute-connected=no 
      redistribute-static=no redistribute-rip=no redistribute-ospf=no 
      redistribute-other-bgp=no out-filter=as-elkdata-out client-to-client-reflection=no 
      ignore-as-path-len=no routing-table="" 
Any suggestions?
 
User avatar
nickshore
Member
Member
Posts: 473
Joined: Thu Mar 03, 2005 4:14 pm
Location: Suffolk, UK.
Contact:

Re: BGP path selection

Thu Apr 04, 2013 6:18 pm

You need to show the routes you have a problem with

do

/ip route print detail where dst-address in x.x.x.x/x
Nick Shore MTCNA MTCWE MTCRE MTCINE MTCTCE
LinITX.com - MultiThread Consultants
Get your MikroTik RBs and Training: http://linitx.com/brand/mikrotik
Official UK MikroTik Distributor
IRC chan: #routerboard on irc.z.je (IPv4 and IPv6)
 
elkdata
just joined
Topic Author
Posts: 3
Joined: Thu Apr 04, 2013 3:01 pm

Re: BGP path selection

Fri Apr 05, 2013 10:21 am

You need to show the routes you have a problem with

do

/ip route print detail where dst-address in x.x.x.x/x

I censored output little bit, hopefully this is not problem. There is lots longer prefixes, they all are only announced by 3327
> ip route print detail where dst-address in 212.47.192.0/19  
Flags: X - disabled, A - active, D - dynamic, 
C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme, 
B - blackhole, U - unreachable, P - prohibit 
343 ADb  dst-address=212.47.192.0/19 gateway=88.196.97.X 
        gateway-status=88.196.97.X reachable via  ether11 distance=20 scope=40 
        target-scope=10 bgp-as-path="3249,3327" bgp-origin=igp 
        bgp-communities=3249:10233,3249:11000,3249:11002 received-from=Elion-1 

348  Db  dst-address=212.47.192.0/19 gateway=212.47.215.Y 
        gateway-status=212.47.215.Y reachable via  ether10 distance=20 scope=40 
        target-scope=10 bgp-as-path="3327" bgp-origin=igp received-from=Linx-1 

 
User avatar
mrz
MikroTik Support
MikroTik Support
Posts: 5942
Joined: Wed Feb 07, 2007 12:45 pm
Location: Latvia
Contact:

Re: BGP path selection

Fri Apr 05, 2013 10:39 am

Does both peers use the same BGP instance?
 
elkdata
just joined
Topic Author
Posts: 3
Joined: Thu Apr 04, 2013 3:01 pm

Re: BGP path selection

Fri Apr 05, 2013 11:12 am

Does both peers use the same BGP instance?
No. I can see where it goes. So, only way to get best AS path is by using same instance? Any workarounds for this?

Who is online

Users browsing this forum: No registered users and 8 guests