From: Victor Cappuccio (cvictor@protokolgroup.com)
Date: Mon Apr 24 2006 - 00:36:45 GMT-3
Yeap Thank you so much
Rack1R2#show ip bgp
88.88.88.0
BGP routing table entry for 88.88.88.0/24, version
219
Paths: (1 available, best #1, table
Default-IP-Routing-Table)
Flag:
0x820
Advertised to
update-groups:
1
300
164.1.12.1 from 164.1.12.1
(10.1.1.1)
Origin IGP, metric 200, localpref 100, valid, external,
best
Rack1R1#show run | b bgp
router bgp 300
no synchronization
bgp router-id 10.1.1.1
bgp log-neighbor-changes
network 164.1.13.0 mask 255.255.255.0 route-map SETCOM
neighbor 164.1.12.2 remote-as 200
neighbor 164.1.12.2 route-map TOR2-SETMED out
neighbor 164.1.13.3 remote-as 200
neighbor 164.1.13.3 route-map TOR3-SETMED out
neighbor 164.1.13.3 advertise-map EXISTE non-exist-map NOEXOSTE
neighbor 164.1.18.8 remote-as 300
neighbor 164.1.18.8 default-originate
neighbor 164.1.18.8 route-map FILTRO out
no auto-summary
Rack1R1#show route
route-map SETCOM, permit, sequence 10
Match clauses:
Set clauses:
community no-advertise
Policy routing matches: 0 packets, 0 bytes
route-map FILTRO, permit, sequence 10
Match clauses:
ip address prefix-lists: FILTRO
Set clauses:
Policy routing matches: 0 packets, 0 bytes
route-map NOEXOSTE, permit, sequence 10
Match clauses:
ip address prefix-lists: 88
Set clauses:
Policy routing matches: 0 packets, 0 bytes
route-map EXISTE, permit, sequence 10
Match clauses:
ip address prefix-lists: EXISTE?
Set clauses:
Policy routing matches: 0 packets, 0 bytes
route-map TOR2-SETMED, permit, sequence 10
Match clauses:
ip address prefix-lists: 88
Set clauses:
metric 200
Policy routing matches: 0 packets, 0 bytes
route-map TOR2-SETMED, permit, sequence 1000
Match clauses:
Set clauses:
Policy routing matches: 0 packets, 0 bytes
route-map TOR3-SETMED, permit, sequence 10
Match clauses:
ip address prefix-lists: 88
Set clauses:
metric 100
as-path prepend 300 301
Policy routing matches: 0 packets, 0 bytes
route-map TOR3-SETMED, permit, sequence 1000
Match clauses:
Set clauses:
Policy routing matches: 0 packets, 0 bytes
Brian McGahan escribis:
You can use BGP conditional advertisement on R1 to accomplish
this.
HTH,
Brian McGahan, CCIE #8593 bmcgahan@internetworkexpert.com
Internetwork Expert, Inc. http://www.InternetworkExpert.com Toll Free: 877-224-8987 x 705
Outside US: 775-826-4344 x 705
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-----Original Message-----
From: nobody@groupstudy.com [ mailto:nobody@groupstudy.com ] On Behalf
Of
Victor Cappuccio
Sent: Sunday, April 23, 2006 6:11 PM
To: CCIE LAB
Subject: How to override the BGP Decision Process if possible?
Hello All
R1 in an AS 300 that is a dual homed system, lets say
Router 1 in Remote-as 300
Router 1 neighbor R2 in remote-as 200
Router 1 neighbor R3 in remote-as 200
Now the link between R1 and R3 is very slow, but the administrator of
AS
200 had set a Local Pref to 400 in R3 and 200 in R2.. Just for
example. -
Not real world situation. - but it could happen ;)
Is there any way I could override this situation??
Rack1R2#show ip bgp 88.88.88.0
BGP routing table entry for 88.88.88.0/24, version 43
Paths: (2 available, best #1, table Default-IP-Routing-Table)
Flag: 0x820
Advertised to update-groups:
1
300 300 301, (Received from a RR-client)
164.1.23.3 from 164.1.23.3 (10.3.3.3)
Origin IGP, metric 100, localpref 400, valid, internal, best
300
164.1.12.1 from 164.1.12.1 (10.1.1.1)
Origin IGP, metric 200, localpref 100, valid, external
Ok the BGP decision process goes like this Next Hop Reachable? ->
Weight
-> Local Pref -> AS-PATH -> MED -> External (EBGP) is better than
confederation external, which is better than IBGP
But … lets look it this way, I’m the customer of As 200
and
the administrators are very busy. is there any way to deal with this
issue ? (beside shutting down my neighbor relation to R3) Also for
other
good reasons the internal network of AS 200 (which I do not concern)
is
using more Links to get to my AS 300
Thanks
Victor.-
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