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New Member

BGP Problem for 2 AS

Hi ,

The problem is of Routing Advertisement with SingTel.

The situation is this,SkyCom & Brain both are connected to the Internet Backbone through SingTel.Now from some sites in USA,we have almost equal delay but from some sites we have a much delay as compared to Brain.e.g ; From route-server.cerf.net we have a delay of 540 ms and brain has 330 ms .When I traceroute from that router,we go to SingTel via another Path and Brain goes the other path.Now when I complained this thing to SingTel they said that Brain is also running its BGP while we rely on SingTel as we have the AS of SingTel.

You please just check by Telneting route-server.cerf.net and doing traceroute to both SKYCOM (203.208.143.129) & BRAIN (203.128.7.1).

Please guide me that How should I be able to solve this problem.Also let me know Is it SingTel's BGP Routing Problem that we are facing more delay or is it due to CERF Net's IGP.Is the Brain running BGP more efficiently than SingTel ?

Following is the response I get for SkyCom and Brain from Cerf Net's Router .

route-server>sh ip bgp 203.128.7.0

BGP routing table entry for 203.128.0.0/19, version 4798258

Paths: (1 available, best #1)

Advertised to non peer-group peers:

65.104.120.78 192.215.199.110

1740 7018 1 7473 17911

134.24.127.30 from 134.24.127.30 (134.24.127.30)

Origin incomplete, metric 35, localpref 100, valid, external, best

Community: 1740:666

route-server>sh ip bgp 203.208.143.0

BGP routing table entry for 203.208.128.0/19, version 4817825

Paths: (1 available, best #1)

Advertised to non peer-group peers:

65.104.120.78 192.215.199.110

1740 6461 7473

134.24.127.30 from 134.24.127.30 (134.24.127.30)

Origin IGP, metric 155, localpref 100, valid, external, best

Community: 1740:666

1 REPLY
New Member

Re: BGP Problem for 2 AS

The above examples reflect that the routes are being preferred from different upstreams AS6461 (above net) and as7018 (ATT-Internet). If both sit behind AS7473 this would be unexpected unless a route is being filtered.

Looking at AS6461's looking glass I can see 203.128.7.0 is also best from AS7473.

The problem is likely to be that AS1740 needs to update its AS-PATH filter to above net to accept _17911$

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