BGP VPNv4 Route Reflector

Posted: quinta-feira, 19 de fevereiro de 2015 by Wairisson Gomes in
0

Por padrão, a configuração BGP  que é feita no processo  bgp será aplicável para a Address Family Identifier - AFI IPv4 unicast . Na topologia abaixo, R2 e R4 atuam como PE routers com uma  VPN chamada COKE configurada. R3 atua como um Route reflector para R2 e R4.



As configurações :
R2 Configuration:
-----------------------
router bgp 100
no synchronization
bgp router-id 100.1.2.2
bgp log-neighbor-changes
neighbor 100.1.3.3 remote-as 100
neighbor 100.1.3.3 update-source Loopback0
neighbor 150.1.12.1 remote-as 200
no auto-summary
!
address-family vpnv4
neighbor 100.1.3.3 activate
neighbor 100.1.3.3 send-community extended
exit-address-family
!
address-family ipv4 vrf COKE
redistribute ospf 1 vrf COKE match internal external 1 external 2
no synchronization
exit-address-family

R4 Configuration:
---------------------
router bgp 100
no synchronization
bgp router-id 100.1.4.4
bgp log-neighbor-changes
neighbor 100.1.3.3 remote-as 100
neighbor 100.1.3.3 update-source Loopback0
no auto-summary
!
address-family vpnv4
neighbor 100.1.3.3 activate
neighbor 100.1.3.3 send-community both
exit-address-family
!
address-family ipv4 vrf COKE
redistribute ospf 1 vrf COKE match internal external 1 external 2
no synchronization
exit-address-family

R3 Configuration:
---------------------
router bgp 100
no synchronization
bgp router-id 100.1.3.3
bgp log-neighbor-changes
neighbor 100.1.2.2 remote-as 100
neighbor 100.1.2.2 update-source Loopback0
neighbor 100.1.2.2 route-reflector-client
neighbor 100.1.4.4 remote-as 100
neighbor 100.1.4.4 update-source Loopback0
neighbor 100.1.4.4 route-reflector-client
no auto-summary
!
address-family vpnv4
neighbor 100.1.2.2 activate
neighbor 100.1.2.2 send-community both
neighbor 100.1.4.4 activate
neighbor 100.1.4.4 send-community both
exit-address-family

A configuração acima mostra que  R3 está configurado como router reflector com  R2 e R4 como clientes. Pode ser notado que, o router reflector não é configurado no modo VPNv4 AFI. Então R3 refletirá apenas rotas IPv4 BGP a partir de  R4 e R2 e não rotas VPNv4.

R4#
R4#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R4(config)#router bgp 100
R4(config-router)#network 100.1.4.4 mask 255.255.255.255
R4(config-router)#end
R4# sh ip bgp
BGP table version is 2, local router ID is 100.1.4.4
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
*> 100.1.4.4/32 0.0.0.0 0 32768 i
R4#
R2#sh ip bgp
BGP table version is 3, local router ID is 100.1.2.2
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>i100.1.4.4/32 100.1.4.4 0 100 0 i
R2#

As rotas VPNv4 não estarão presentes na tabela BGP de R2.

R4#show ip bgp vpnv4 all 10.1.58.0
BGP routing table entry for 100:1:10.1.58.0/24, version 11
Paths: (1 available, best #1, table COKE)
Advertised to update-groups:
1
Local
10.1.46.6 (via COKE) from 0.0.0.0 (100.1.4.4)
Origin incomplete, metric 97, localpref 100, weight 32768, valid, sourced, best
Extended Community: RT:100:1 OSPF DOMAIN ID:0x0005:0x000000010200
OSPF RT:0.0.0.0:2:0 OSPF ROUTER ID:10.1.46.4:512
mpls labels in/out 22/nolabel
R4#
R2#show ip bgp vpnv4 all 10.1.58.0
% Network not in table
R2#

Agora configurando a reflexão de rotas dentro do modo VPNv4 fará com o que o router reflector reflita ou propague os prefixos recebidos via VPNv4 para seus demais clientes para os quais esta address family esteja ativa.

R3#
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#router bgp 100
R3(config-router)#address-family vpnv4
R3(config-router-af)#neighbor 100.1.2.2 route-reflector-client
R3(config-router-af)#neighbor 100.1.4.4 route-reflector-client
R3(config-router-af)#end
R3#
R4#show ip bgp vpnv4 all 10.1.58.0
BGP routing table entry for 100:1:10.1.58.0/24, version 11
Paths: (1 available, best #1, table COKE)
Advertised to update-groups:
1
Local
10.1.46.6 (via COKE) from 0.0.0.0 (100.1.4.4)
Origin incomplete, metric 97, localpref 100, weight 32768, valid, sourced, best
Extended Community: RT:100:1 OSPF DOMAIN ID:0x0005:0x000000010200
OSPF RT:0.0.0.0:2:0 OSPF ROUTER ID:10.1.46.4:512
mpls labels in/out 22/nolabel
R4#
R2#show ip bgp vpnv4 all 10.1.58.0
BGP routing table entry for 100:1:10.1.58.0/24, version 30
Paths: (1 available, best #1, table COKE)
Flag: 0x820
Not advertised to any peer
Local
100.1.4.4 (metric 30) from 100.1.3.3 (100.1.3.3)
Origin incomplete, metric 97, localpref 100, valid, internal, best
Extended Community: RT:100:1 OSPF DOMAIN ID:0x0005:0x000000010200
OSPF RT:0.0.0.0:2:0 OSPF ROUTER ID:10.1.46.4:512
Originator: 100.1.4.4, Cluster list: 100.1.3.3
mpls labels in/out nolabel/22
R2#

 Traduzido do link: http://nagendrakumar-nagendra.blogspot.com.br/2009/05/bgp-vpnv4-route-reflector.html 

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