distinguishing eBGP from show ip BGP
motamedi at cs.uoregon.edu
Wed Mar 11 19:42:06 UTC 2015
What I ultimately want to determine, is the location of the AS connection.
I know for example the router is in, say LA. If hot potato lets me to send
the packet to the neighbor AS then they have an AS connection in LA, right?
Going back to my example does the fact that the entry does not have 'i'
mean that I can send it to AS2828 on the next hop.
Network Next Hop Metric LocPrf Weight Path
* 22.214.171.124/15 126.96.36.199 3 0 2828 209 i
* 188.8.131.52 2 0 2828 209 i
* 184.108.40.206 3 0 2828 209 i
* 220.127.116.11 3 0 2828 209 i
*> 18.104.22.168 2 0 2828 209 i
Reza Motamedi (R.M)
Graduate Research Fellow
Oregon Network Research Group
Computer and Information Science
University of Oregon
On Wed, Mar 11, 2015 at 3:30 PM, Mark Tinka <mark.tinka at seacom.mu> wrote:
> 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?
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