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Community Member

BGP and RIB

Hello,

Scenario:

Two data centers (Data Center A and B) in different states. 

Company X owns x.x.1.0/24 and x.x.2.0/24 AS:1234

Data center A gets the full routing table for ISP1 and advertises x.x.1.0/24 

Data center B gets DF only from ISP2 and advertises x.x.2.0/24

 

Issue:

Data center A is not getting x.x.2.0/24 from ISP2.   ISP2 does advertise x.x.2.0/24 but Company’s bgp peering router doesn’t see a route for x.x.2.0/24

ISP2 is sending x.x.2.0/route like this

  Prefix                  Nexthop              MED     Lclpref    AS path

* x.x.2.0/24         Self                                    444 555 1234 I

 

Question?

Is the reason why the wan rt peering with ISP2 not seeing the route to x.x.2.0/24 because it sees its own AS number in the AS-path?  

 

Thank you in advance for your input.  

 

Cheers! 

1 ACCEPTED SOLUTION

Accepted Solutions

Hi,You are correct. In this

Hi,

You are correct. In this scenario, DC-A should see x.x.2.0/24 from ISP1, however, it should be dropped from its BGP RIB on receipt due to as-path attribute.

This is normal operation of BGP.

2 REPLIES
Community Member

Clarification TYPO!!! Issue

Clarification TYPO!!! 

Issue:

Data center A is not getting x.x.2.0/24 from ISP1.   ISP1 does advertise x.x.2.0/24 but Company’s bgp peering router doesn’t see a route for x.x.2.0/24

ISP1 is sending x.x.2.0/route like this

  Prefix                  Nexthop              MED     Lclpref    AS path

* x.x.2.0/24         Self                                    444 555 1234 I

 

Thank you! 

Hi,You are correct. In this

Hi,

You are correct. In this scenario, DC-A should see x.x.2.0/24 from ISP1, however, it should be dropped from its BGP RIB on receipt due to as-path attribute.

This is normal operation of BGP.

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