RE: summary route

From: Richard Dumoulin (richard.dumoulin@vanco.es)
Date: Tue Jun 01 2004 - 06:55:41 GMT-3

Yasser,

 I don't think it has anything to do with confederations. It's just the bgp
process advertising the summary route but I may be wrong. Let's wait for
your test when you have time,

--Richard

-----Original Message-----
From: Yasser Aly [mailto:blackyeyes00@hotmail.com]
Sent: martes, 01 de junio de 2004 11:50
To: Richard Dumoulin
Subject: RE: summary route

Hi Richard,

  I don't have access to my devices now. Possibly at night I can re-run the
test and post my config.
However, for your test scenario I noticed one thing that might be the reason

of this.
In your scenario you are using confedration peers. I am not aware of any
reason that can make output differ because it is inside a confedration but
this appears to me the only difference between my test and yours. I used
normal AS numbers not private ones and was not running confedrations.

If you have access to your devices now you can check with my scenario.
Anyway, I will simulate it again at night and post my config.

Cheers,
Yasser

>From: 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: Tue, 1 Jun 2004 08:59:00 +0100
>
>Yasser, can you post your test ? Here is mine:
>
>First I have this:
>
>r2#sh run | b bgp
>router bgp 65501
> no synchronization
> bgp router-id 2.2.2.2
> bgp log-neighbor-changes
> bgp confederation identifier 12345
> bgp confederation peers 65505
> neighbor 172.16.30.1 remote-as 65501
> neighbor 172.16.30.18 remote-as 65505
> no auto-summary
>
>
>r2#sh ip bgp
>BGP table version is 34, local router ID is 2.2.2.2 >Status codes: s
suppressed, d damped, h history, * valid, > best, i - >internal,
> r RIB-failure, S Stale
>Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
>r>i10.1.1.0/24 172.16.30.1 0 100 0 i
>r>i10.1.3.0/24 172.16.30.3 0 100 0 i
>*>i10.1.6.0/24 172.16.30.34 0 100 0 67 i
>*> 10.10.10.0/24 10.1.5.2 0 200 0 (65505)
10 i
>r>i10.40.4.0/24 172.16.30.22 0 100 0 (65504)
i
>r> 10.50.5.0/24 172.16.30.18 0 100 0 (65505)
i
>*>i10.70.7.0/24 172.16.30.34 0 100 0 67 i
>
>
>And I am going to summarize 10.0.0.0/8 into bgp:
>
>But first I advertise the classful and see if it appears in the bgp fib:
> >r2(config)#router bgp 65501 >r2(config-router)#netw
>r2(config-router)#network 10.0.0.0 >r2(config-router)#^Z > >
>But there is no way the network enters the table because the network
does
>not exist in the local table:
>
>r2#sh ip bgp
>BGP table version is 34, local router ID is 2.2.2.2 >Status codes: s
suppressed, d damped, h history, * valid, > best, i - >internal,
> r RIB-failure, S Stale
>Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
>r>i10.1.1.0/24 172.16.30.1 0 100 0 i
>r>i10.1.3.0/24 172.16.30.3 0 100 0 i
>*>i10.1.6.0/24 172.16.30.34 0 100 0 67 i
>*> 10.10.10.0/24 10.1.5.2 0 200 0 (65505)
10 i
>r>i10.40.4.0/24 172.16.30.22 0 100 0 (65504)
i
>r> 10.50.5.0/24 172.16.30.18 0 100 0 (65505)
i
>*>i10.70.7.0/24 172.16.30.34 0 100 0 67 i
>
>
>So I enter auto-summary in the bgp process:
>
>r2#conf t
>Enter configuration commands, one per line. End with CNTL/Z.
>r2(config)#router bgp 65501 >r2(config-router)#auto
>r2(config-router)#auto-summary
>r2(config-router)#^Z
>r2#
>r2#
>*Mar 1 18:11:33.762: %SYS-5-CONFIG_I: Configured from console by
consoles
>r2#sh deb
>IP routing:
> BGP debugging is on
>
>
>r2#
>*Mar 1 18:12:31.529: BGP: Applying map to find origin for 10.0.0.0/24
>r2#sh ip bgp >BGP table version is 35, local router ID is 2.2.2.2
>Status codes: s suppressed, d damped, h history, * valid, > best, i -
>internal,
> r RIB-failure, S Stale
>Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
>*> 10.0.0.0 0.0.0.0 0 32768 i
>r>i10.1.1.0/24 172.16.30.1 0 100 0 i
>r>i10.1.3.0/24 172.16.30.3 0 100 0 i
>*>i10.1.6.0/24 172.16.30.34 0 100 0 67 i
>*> 10.10.10.0/24 10.1.5.2 0 200 0 (65505)
10 i
>r>i10.40.4.0/24 172.16.30.22 0 100 0 (65504)
i
>r> 10.50.5.0/24 172.16.30.18 0 100 0 (65505)
i
>*>i10.70.7.0/24 172.16.30.34 0 100 0 67 i
>
>
>I even ran "debug ip bgp" so we can see what happens. I think
that I have
>confirmed the BGP faq
>http://www.cisco.com/en/US/tech/tk365/tk80/technologies_q_and_a_item0918
6a00
>800949e8.shtml#five
>
>Yasser could you please post your test ?
>
>Regards
>
>--Richard
>
>
>
>
>
>
>
>-----Original Message-----
>From: Yasser Aly [mailto:blackyeyes00@hotmail.com]
>Sent: martes, 01 de junio de 2004 0:37
>To: Richard Dumoulin; ahmed.mustafa@sbcglobal.net
>Cc: ccielab@groupstudy.com
>Subject: RE: summary route
>
>
>
>Richard,
>
> Just tested it before sending my mail to the list. auto-summary only
works
>with redistributed routes.
>
>Hope to hear others comments about this to confirm. >Yasser >
>>From: 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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