From: Thor Kopp (thorkopp@googlemail.com)
Date: Tue Jun 03 2008 - 05:25:27 ART
If you are not using conderations then they perform the same function as
Narbik has listed above. When using confederations, routes set with the
local-as community won't be advertised to confederation eBGP peers while
routes marked with no-export will still be advertised to confederation eBGP
peers.
- Thor
On Tue, Jun 3, 2008 at 5:43 AM, Chuck Ryan (chryan) <chryan@cisco.com>
wrote:
> 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.
> >>
> >>
> >>
> _______________________________________________________________________
> >> Subscription information may be found at:
> >> http://www.groupstudy.com/list/CCIELab.html
> >>
> >>
> >>
> >>
> >>
> >
> >
> > --
> > Narbik Kocharians
> > CCSI#30832, CCIE# 12410 (R&S, SP, Security)
> > www.Net-Workbooks.com <http://www.net-workbooks.com/>
> > Sr. Technical Instructor
>
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Tue Jul 01 2008 - 06:23:20 ART