From: Chuck Ryan (chryan) (chryan@cisco.com)
Date: Tue Jun 03 2008 - 01:43:24 ART
What was the explanation regarding confederations? That must have been
sent unicast and not to the list. Based on Narbik's response, local-as
and no-export are the same? That's how I understood that explanation.
Please correct me if I am mis-understanding that.
Thanks,
Chuck
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
John Jones
Sent: Monday, June 02, 2008 9:20 PM
To: ccielab@groupstudy.com
Subject: Re: BGP Communities - no-export vs. local-AS
Thanks Lloyd and Narbik. I kind of figured that it could be associated
with confederations.
Thanks Narbik for the detailed explanation. It looks like it is a matter
of where the advertisement "boundary" lies.
John
On Mon, Jun 2, 2008 at 8:46 PM, Narbik Kocharians <narbikk@gmail.com>
wrote:
> Besides the *confederation*, here are some choices:
>
> Let's say you have R1 in AS 100 and R2 in AS 200. R1 needs to
> advertise network 1.0.0.0/8 to R2, but it does NOT want the routers in
> AS 200 advertise that route to any of their EBGP peers, R1 can
> accomplish this task in two ways:
>
> 1. R1 can identify the network, in this case 1.0.0.0/8, then configure
> a route-map and set the community to *no-export* and then send
> community and the route-map to R2.
> 2. R1 can identify the network, in this case 1.0.0.0/8, then configure
> a route-map and then set the community to *local-as* and then send the
> community and the route-map to R2.
>
> Now if R2 is advertising network 2.0.0.0/8 and it want that network to
> stay local (meaning in its own AS) and NOT be advertised to any EBGP
> peer/s,
> R2 can be configured using one of the following:
>
> 1. R2 can be configured to advertise network (2.0.0.0/8) using a
> network statement with a route-map, and the route-map just sets the
> community to * local-as*.
> 2. R2 can be configured to advertise network (2.0.0.0/8) using a
> network statement with a route-map, and the route-map just sets the
> community to * no-export*.
>
>
> On Mon, Jun 2, 2008 at 5:57 PM, John Jones <acer0001@gmail.com> wrote:
>
>> After searching the DocCD, I have been unable to find out the
>> difference between these, other than they are opposite logic.
>> no-export means don't sent a BGP update out of the AS. local-AS means
>> keep the update within the AS that the router is in.
>>
>> Is the difference when using confederations? I can see there the
>> significance, but is this the only one?
>>
>> Thanks, guys.
>>
>> John Jones
>> Networking, Linux & Storage Interconnect Trainer Dell Inc.
>>
>>
>>
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