distinguishing eBGP from show ip BGP

Mark Tinka mark.tinka at seacom.mu
Wed Mar 11 19:30:46 UTC 2015


On 11/Mar/15 21:22, Reza Motamedi wrote:
>
> Thanks Mark for the reply. Let me try to check what I understood is 
> correct. Does the 'i' on the left (status code) only shows whether the 
> prefix belongs to this AS?
>

Status-code "i" just means the entry was learned by "this" router via 
iBGP. It does not mean the entry belongs to "this AS".

A locally-generated route can be thought of as "belonging to this AS", 
however, a router cannot assert that a locally-generated route "belongs 
to this AS". It just asserts that the route was locally-generated within 
the AS. Ownership of the route is data that needs to be gleaned from 
other sources, e.g., RIR WHOIS data, speaking to the operator, e.t.c.

Whatever the case, a locally-generated route would not have an AS_PATH. 
That is an easy way to tell for such a use-case.

> What I want to figure out is if this two ASes (the owner of the router 
> and and the first one on the AS-PATH) connect at the location of the 
> router, or if packets need to stay for some hops in the local AS.
>

So you want to determine whether traffic is hot- or cold-potato 
forwarding from the point of view of your reference router?

Mark.


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