Re: BGP aggregate-address with advertise-map

That's exactly the solution I tried to achieve.
I tested your solution 1) and 2) and both work perfectly.
Thanks very much :-)

Config R6 and resulting routes on R4:
R6
router bgp 200
 aggregate-address 200.0.0.0 255.255.252.0 as-set *suppress-map ADVERTISE*

ip prefix-list EIGRP seq 5 permit 200.0.0.0/24
ip prefix-list EIGRP seq 10 permit 200.0.1.0/24

route-map ADVERTISE deny 10
 match ip address prefix-list EIGRP
!
route-map ADVERTISE permit 20

R4 (200.0.2.0 / 200.0.3.0 are not advertised) --> desired result :-)

* i200.0.0.0 158.5.3.3 2297856 100 0 200 ?
*> 158.5.46.6 2297856 0 200 ?
* i200.0.0.0/22 158.5.3.3 0 100 0 200 ?
*> 158.5.46.6 0 0 200 ?
* i200.0.1.0 158.5.3.3 2297856 100 0 200 ?

----------------------------------------------------------------------------------------------------------------------------------------------
R6
router bgp 200
  aggregate-address 200.0.0.0 255.255.252.0 *summary-only*

 neighbor 158.5.46.4 *unsuppress-map *UNSUPRESS
! snip
 neighbor 204.12.5.3 *unsuppress-map* UNSUPRESS

route-map UNSUPRESS permit 10
 match ip address prefix-list EIGRP

ip prefix-list EIGRP seq 5 permit 200.0.0.0/24
ip prefix-list EIGRP seq 10 permit 200.0.1.0/24

R4
* i200.0.0.0 158.5.3.3 2297856 100 0 200 ?
*> 158.5.46.6 2297856 0 200 ?
* i200.0.0.0/22 158.5.3.3 0 100 0 200 i
*> 158.5.46.6 0 0 200 i
* i200.0.1.0 158.5.3.3 2297856 100 0 200 ?
*> 158.5.46.6 2297856 0 200 ?

----------------------------------------------------------------------------------------------------------------------------------------------

On Mon, Sep 6, 2010 at 2:01 AM, karim jamali <karim.jamali_at_gmail.com> wrote:

> Dear Selamat,
>
> The advertise-map only has to do as per my knowledge with the Autonomous
> System Path manipulation let us say you have two sub-routes A/B part being
> aggregated as a major subnet X. A has its own as-path and B also has its own
> as-path, thus by default the autonomous system path of A & B will be in an
> AS-SET format and will both form the AS-Path for the aggregate X.
>
> Check this paragraph taken from Doc-CD:
>
> http://www.cisco.com/en/US/docs/ios/12_3/iproute/command/reference/ip2_a1g.html#wp1037074
>
> "Using the* advertise-map *keyword selects specific routes that will be
> used to build different components of the aggregate route, such as AS_SET or
> community. This form of the *aggregate-address *command is useful when the
> components of an aggregate are in separate autonomous systems and you want
> to create an aggregate with AS_SET, and advertise it back to some of the
> same autonomous systems. You must remember to omit the specific autonomous
> system numbers from the AS_SET to prevent the aggregate from being dropped
> by the BGP loop detection mechanism at the receiving router. IP access lists
> and autonomous system path access lists *match* clauses are supported. "
>
> Back to your example where you have a summary and 4 routes on R6 and you
> want the summary with only two routes to appear on R4
>
>
> *> 200.0.0.0 54.5.1.254 2297856 32768 ?
> *> 200.0.0.0/22 0.0.0.0 32768 i
> *> 200.0.1.0 54.5.1.254 2297856 32768 ?
> *> 200.0.2.0 54.5.1.254 2297856 32768 ?
> *> 200.0.3.0 54.5.1.254 2297856 32768 ?
>
> Well I guess it could be done with two solutions:
>
> 1)Keep the aggregate without-summary keyword and use a neighbor
> suppress-map and suppress the unneeded subnets (200.0.2.0, 200.0.3.0)
>
> 2)Put a summary-only keyword at the end of the aggregate and unsuppress the
> two routes the ones you need (200.0.0.0, 200.0.1.0) for this neighbor
> (neigbor a.b.c.d unsupress-map)
>
> HTH
>
> On Sun, Sep 5, 2010 at 2:56 PM, selamat pagi <ketimun_at_gmail.com> wrote:
>
>> Can this be achieved with an advertise-map ?
>>
>>
>> On R6 I receive 4 routes via EIGRP and redistribute them into BGP then
>> send
>> it via EBGP to R4.
>> On R4 I need to get a summary-route and the specific-routes for
>> 200.0.0.0/24and
>> 200.0.1.0/24.
>> I cannot change the aggregate-mask.
>>
>> R6
>> router bgp 200
>> aggregate-address 200.0.0.0 255.255.252.0 advertise-map ADVERTISE
>> redistribute eigrp 10
>> neighbor 158.5.46.4 remote-as 100 --> R4
>>
>> route-map ADVERTISE permit 10
>> match ip address prefix-list EIGRP
>> !
>> route-map ADVERTISE deny 20
>> !
>> ip prefix-list EIGRP seq 5 permit 200.0.0.0/24
>> ip prefix-list EIGRP seq 10 permit 200.0.1.0/24
>>
>>
>> --------------------------------------------------------------------------------
>> R6#sh ip bg
>> *> 200.0.0.0 54.5.1.254 2297856 32768 ?
>> *> 200.0.0.0/22 0.0.0.0 32768 i
>> *> 200.0.1.0 54.5.1.254 2297856 32768 ?
>> *> 200.0.2.0 54.5.1.254 2297856 32768 ?
>> *> 200.0.3.0 54.5.1.254 2297856 32768 ?
>>
>> R6#sh ip route eigrp
>> D 200.0.0.0/24 [90/2297856] via 54.5.1.254, 01:22:00, Serial0/0/0.101
>> D 200.0.1.0/24 [90/2297856] via 54.5.1.254, 01:22:00, Serial0/0/0.101
>> D 200.0.2.0/24 [90/2297856] via 54.5.1.254, 01:22:00, Serial0/0/0.101
>> D 200.0.3.0/24 [90/2297856] via 54.5.1.254, 01:22:00, Serial0/0/0.101
>>
>> --------------------------------------------------------------------------------
>>
>> R4#sh ip bgp vpn all
>> * i200.0.0.0 158.5.3.3 2297856 100 0 200 ?
>> *> 158.5.46.6 2297856 0 200 ?
>> * i200.0.0.0/22 158.5.3.3 0 100 0 200 i
>> *> 158.5.46.6 0 0 200 i
>> * i200.0.1.0 158.5.3.3 2297856 100 0 200 ?
>> *> 158.5.46.6 2297856 0 200 ?
>> * i200.0.2.0 158.5.3.3 2297856 100 0 200 ? -->
>> don't expect route here
>> *> 158.5.46.6 2297856 0 200 ?
>> * i200.0.3.0 158.5.3.3 2297856 100 0 200 ? -->
>> don't expect route here
>>
>>
>> thanks for your help,
>> keti
>>
>>
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>
>
> --
> KJ

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Received on Tue Sep 07 2010 - 08:01:59 ART