Re: suppress-map vs advertise-map

Sorry, this was supposed to go on the CCA announcement. Multitasking.....

Charles

                                                                                                                                 
  From: Charles Henson/RegionsTechnology/MGM/RFC
                                                                                                                                 
  To: Bryan Bartik <bbartik_at_ipexpert.com>
                                                                                                                                 
  Cc: "ccielab_at_groupstudy.com" <ccielab_at_groupstudy.com>, S Malik <ccie.09_at_gmail.com>, Jose Miguel Huertas
              <JoseMiguel.huertas_at_telindus.es>, "moditw_at_gmail.co.za" <moditw_at_gmail.co.za>, nobody_at_groupstudy.com
                                                                                                                                 
  Date: 06/29/2009 10:40 AM
                                                                                                                                 
  Subject: Re: suppress-map vs advertise-map
                                                                                                                                 

Wonderful. It's not that I don't agree. But for those of us just breaking
into our CCIE level certifications like myself, how does it impact our
value both to a company and our value in terms of income? Based on what I'm
reading and watching, it looks like this will be a very small subset of the
general networking populous. I guess that will keep things alive...

Charles

                                                                                                                                 
  From: Bryan Bartik <bbartik_at_ipexpert.com>
                                                                                                                                 
  To: S Malik <ccie.09_at_gmail.com>
                                                                                                                                 
  Cc: Jose Miguel Huertas <JoseMiguel.huertas_at_telindus.es>, "moditw_at_gmail.co.za" <moditw_at_gmail.co.za>,
              "ccielab_at_groupstudy.com" <ccielab_at_groupstudy.com>
                                                                                                                                 
  Date: 06/29/2009 10:26 AM
                                                                                                                                 
  Subject: Re: suppress-map vs advertise-map
                                                                                                                                 

Here is an example of advertise-map:

http://ccietobe.blogspot.com/2008/07/bgp-advertise-map.html

On Fri, Jun 26, 2009 at 10:11 AM, S Malik <ccie.09_at_gmail.com> wrote:

> When you create an aggregate address using aggregate-address x.x.x.x
> m<mask>, then bgp announces aggregate address and all specific networks
to
> its neighbors.
>
> e,g if you have four swbnets 192.168.0.0/24, 192.168.1.0/24,
> 192.168.2.0/24and
> 192.168.3.0/24 and you like to aggregate them, you will use
> "aggregate-address 192.168.0.0 255.255.252.0. It will send one aggregate
> i.e
> 192.168.0.0/22 plus all the four subnets to its neighbors.
> Now you like BGP to advertise aggregate and three subnets and filter
> 192.168.3.0/24 subnet then you will use suppress map. For suppress map to
> filter a route, you will need to create a route-map, match ip prefix or
> ACL.
> Remember, you will need to use permit in prefix/ACL to get the route
> suppressed.
>
> Now, advertise-map in the context of aggregation is used to control
> aggregation's attributes i.e if an aggregate is used with as-set option,
> then aggregate will inherit the attributes of subnets like community,as#
.
> Now if one AS receives and aggregate with its own AS# in it, it will
reject
> it, so one of the solutions is to use advertise-map to constitute an
> aggregate which has AS#s defined in the route-map.
>
> Also, suppose if one subnet has community no-export, then aggregate will
> inherit the same community. you can take that route out from aggregation
> list using advertise-map and denying the route whose attribute is set to
> no-export. This way aggregate will not inherit the community as well.
>
>
>
> On Fri, Jun 26, 2009 at 2:38 AM, Jose Miguel Huertas <
> JoseMiguel.huertas_at_telindus.es> wrote:
>
> > Hi Modi,
> >
> > When you make a supernet with aggregate-address without summary-only
> > keyword, you can "suppress" some specific networks using suppress-map,
so
> > you would announce the supernet and some specific nets.
> > For example, we have the bgp networks 10.0.1.0/24, 10.0.2.0/24 and
> > 10.0.3.0/24. With aggregate-address we make a supernet 10.0.0.0/22, so
> we
> > would announce this supernet and also the specific nets.
> > If we use a suppress-map, we could make not to announce the network
> > 10.0.2.0/24, so we would announce the supernet and also 10.0.1.0/24 and
> > 10.0.3.0/24
> >
> > With advertise-map you can make a conditional advertise, let's say, if
I
> > have this network on my bgp table, then advertise this other network.
> >
> >
> >
> >
> > -----Mensaje original-----
> > De: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] En nombre de
> > moditw_at_gmail.co.za
> > Enviado el: jueves, 25 de junio de 2009 7:14
> > Para: ccielab_at_groupstudy.com
> > Asunto: suppress-map vs advertise-map
> >
> > Hi Group,
> >
> > I am failing to understand the different between BGP suppress-map and
> > advertise-map subcommands. can someone explain to me the different.
> >
> > Thanks
> > Modi
> >
> >
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--
Bryan Bartik
CCIE #23707 (R&S), CCNP
Sr. Support Engineer - IPexpert, Inc.
URL: http://www.IPexpert.com
Blogs and organic groups at http://www.ccie.net