[c-nsp] Classify geographical traffic with BGP

[Burak Dikici]

   Hello ,

  I have got one internet router running BGP , and this router has got
connections with two different ISPs. One of the ISP is local for my country
and the other ISP's location is outside of my country. I want to classify
geographical traffic with BGP. For example , local traffic to my country
will go through ISP-1 (local ISP) , outside traffic to my country will go
through ISP-2 (outside of my country ISP). What i have to do to achieve that
kind of configuration ? If i have to use AS path filter , how can i find the
local ISP AS path numbers and how can i configure AS path filter for this
request ? Is that enough using the as-path filter just for the national ISP
or should i use it for international ISP also ?

  If i use AS-path filter for both ISP connections , what will happen to
redundancy ? I mean , for example i filter national AS numbers at the
international ISP connection and deny them. Secondly , i filter national AS
numbers at the national ISP connection , permit them and the other AS
numbers will be denied. In this situation , what will happen if the local
ISP connection goes down ? Because of filtering of the national AS numbers
at the international ISP connection , the BGP table doesn't take any updates
from the local AS numbers. I hope , i could explain the situation correctly.


Kind Regards...

Burak Dikici