From: Richard Dumoulin (richard.dumoulin@vanco.es)
Date: Tue Jun 01 2004 - 05:27:08 GMT-3
Hi Georg, I did not mentioned to put only the auto-summary. I said that the
classful network had also to be entered. This is how I understood it from
the BGP faq.
Do you see anything strange in my test ? I am asking you this because there
seems to be many people doubting. I don0t want to miss anything :)))
Regards
--Richard
-----Original Message-----
From: Georg Pauwen [mailto:pauwen@hotmail.com]
Sent: martes, 01 de junio de 2004 9:51
To: Richard Dumoulin; blackyeyes00@hotmail.com; ahmed.mustafa@sbcglobal.net
Cc: ccielab@groupstudy.com
Subject: RE: summary route
Hello Richard,
BGP would need the summary route in the routing table, and just turning on
auto-summary will not put it there. You could put a static route to null in
your config for the summarized network...
Can you post your test configuration and the output of show ip route from
the router where you have tested this ?
Regards,
Georg
>From: Richard Dumoulin <richard.dumoulin@vanco.es>
>Reply-To: Richard Dumoulin <richard.dumoulin@vanco.es>
>To: Yasser Aly <blackyeyes00@hotmail.com>, ahmed.mustafa@sbcglobal.net
>CC: ccielab@groupstudy.com
>Subject: RE: summary route
>Date: Mon, 31 May 2004 23:15:53 +0100
>
>Yasser, here I have to disagree. Did you read the BGP faq and did you
>test it ? I did and auto-summary contrary to what the majority of
>people think not only works with redistribution,
>
>--Richard
>
>-----Original Message-----
>From: Yasser Aly [mailto:blackyeyes00@hotmail.com]
>Sent: martes, 01 de junio de 2004 0:11
>To: Richard Dumoulin; ahmed.mustafa@sbcglobal.net
>Cc: ccielab@groupstudy.com
>Subject: RE: summary route
>
>
>Hello,
>
>Possibility #2 will not work.
>
>Auto-summary inside BGP acts only on redistributed routes not on routes
>entered in the BGP via the network command. You will need to
>redistribute the route into BGP and turn on auto-summary. This will
>summarize it to its classful boundary.
>
>Regards,
>Yasser
>===================
>But I already explained !
>
>Let's say R2 is connected to R1 and they run an igp like RIP. On R2,
>configure "ip summary-address rip 156.1.0.0 255.255.0.0". So now R1 has
>the network in his routing table right ? You just injected the summary
>through the igp. Now just redistribute RIP into BGP with filters if you
>wish and you will be advertising the network.
>
>
>2) Another possibility as explained is :
>
>router bgp 1234
>auto-summary
>network 156.1.0.0
>
>
>And that's it. But it might not be the solution as per the requirements
>
>--Richard
>
>
>
>-----Original Message-----
>From: Ahmed Mustafa [mailto:ahmed.mustafa@sbcglobal.net]
>Sent: lunes, 31 de mayo de 2004 7:01
>To: Richard Dumoulin
>Subject: Re: summary route
>
>
>Richard,
>
>I have confused you with my question. I completely understand the BGP
>rules
>for advertising networks. What i was asking is let say that
>
>I have R1 connected to backbone via BGP. on R1 I have subnets of
>network 156.1.0.0 per se
>
>156.1.1.0
>156.1.2.0
>156.1.3.0
>156.1.4.0 and so on.
>
>I know just want to advertise the summary route to B1. The network
>between BB and R1 is on 204.12.1.0/24.
>
>Is there any other solution besides using aggregate to advertise a
>network 156.1.0.0/16 to BB.
>
>Regards,
>
>Ahmed
>
>----- Original Message -----
>From: Richard Dumoulin <mailto:richard.dumoulin@vanco.es>
>To: Ahmed Mustafa <mailto:ahmed.mustafa@sbcglobal.net>
>Cc: ccielab@groupstudy.com <mailto:ccielab@groupstudy.com>
>Sent: Sunday, May 30, 2004 8:38 PM
>Subject: RE: summary route
>
>Ahmed, auto-summary is not only used when redistributing igp into bgp.
>Suppose you have the subnet 156.1.2.0/24 in your local routing table.
>If you enable auto-summary and configure network 156.1.0.0 under BGP,
>you will advertise this route as a classful network.
>
>Attaching a prefix-list is only policing traffic. This is not a way to
>advertise a network. There 4 ways to advertise:
>
>redistribute
>network
>aggregate
>bgp inject-map
>
>So you solution should come from one of these four ways,
>
>HTH,
>
>
>--Richard
>
>
>
>-----Original Message-----
>From: Ahmed Mustafa [mailto:ahmed.mustafa@sbcglobal.net]
>Sent: lunes, 31 de mayo de 2004 4:58
>To: Richard Dumoulin
>Subject: Re: summary route
>
>
>Richard,
>
>I am confused. Under BGP process, the auto-summary keyword is only
>used if I redistribute the route. CCIE labs don't allow to create a
>static route, so that option is no permittable.
>
>2nd option to use aggregate address with the summary-only keyword.
>That is also restricted by the task I am currently doing
>
>3rd option, I thought I could use prefix-list of 156.1.0.0/16 and
>attach it with the neighbor command under the BGP process, but you are
>saying it won't work.
>
>Is it because that I have to have a same route 156.1.0.0/16 in my
>routing table, and then prefix-list can allow only this route to be
>advertiseable to the backbone, and then implicit deny will deny all the
>subnets of 156.1.0.0 network.
>
>Now the question is how to do that.
>
>May be I could just advertise the network 156.1.0.0 under bgp process,
>that will create a 156.1.0.0 route in a BGP table though, not routing
>table.
>
>I am lost.
>
>Any clue.
>
>Ahmed
>
>----- Original Message -----
>From: Richard Dumoulin <mailto:richard.dumoulin@vanco.es>
>To: Ahmed Mustafa <mailto:ahmed.mustafa@sbcglobal.net> ;
>ccielab@groupstudy.com <mailto:ccielab@groupstudy.com>
>Sent: Sunday, May 30, 2004 7:04 PM
>Subject: RE: summary route
>
>
>I don't see how you would end up advertising the route. With the
>prefix-list
>you are just allowing it. I can see three options: --Aggregate command
>--"auto-summary" + "network 156.1.0.0" under the bgp process. --you
>summarise in igp and redistribute it into bgp ,
>
>As the first two options use bgp summary features I would do the last
>one,
>
>HTH,
>
>--Richard
>
>-----Original Message-----
>From: Ahmed Mustafa [mailto:ahmed.mustafa@sbcglobal.net
><mailto:ahmed.mustafa@sbcglobal.net> ]
>Sent: lunes, 31 de mayo de 2004 3:44
>To: ccielab@groupstudy.com
>Subject: summary route
>
>
>If I want to announce a summary route of my internal network towards
>the Backbone router, and not allowed to use the route-summary in BGP.
>
>
>Will the following solution work:
>
>
>ip prefix-list TOBB permit 156.1.0.0/16 -------------------> Assuming
>my internal network is comprise of 156.1.0.0/16 network, and scattered
>throughout the netowork with /24 bit mask.
>
>
>
>router bgp 100
>neighbor 1.1.1.1 remote-as 230
>neighbor 1.1.1.1 prefix-list TOBB out
>
>
>I didn't use the command aggregate-address. I am assuming by saying
>not
>use
>route-summary means I can't use aggregation.
>
>
>The implicit deny at the end should block all the longer routes.
>
>Please advise
>
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