Blog SP: 2013

Setup BGP

Configurar sesiones iBGP y eBGP como muestra la figura. Utilice en iBGP las loopbacks0 para formar sesión en cada AS. Para NLRI dentro de cada AS con sesiones iBGP utilice OSPF.

R2 debe ser Route-Reflector para R1 y R2, además utilice peer-group.

interface FastEthernet0/0

ip ospf network point-to-point

ip ospf 1 area 0

interface Loopback0

ip ospf 1 area 0

interface FastEthernet0/0

ip ospf network point-to-point

ip ospf 1 area 0

interface FastEthernet0/1

ip ospf network point-to-point

ip ospf 1 area 0

interface Loopback0

ip ospf 1 area 0

interface FastEthernet0/1

ip ospf network point-to-point

ip ospf 1 area 0

interface Loopback0

ip ospf 1 area 0

R2#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

10.3.3.3 0 FULL/ - 00:00:37 10.1.23.3 FastEthernet0/1

10.1.1.1 0 FULL/ - 00:00:37 10.1.12.1 FastEthernet0/0

router bgp 10

no synchronization

bgp router-id 10.1.1.1

bgp log-neighbor-changes

neighbor 10.2.2.2 remote-as 10

neighbor 10.2.2.2 update-source Loopback0

neighbor 172.16.14.4 remote-as 20

no auto-summary

router bgp 10

no synchronization

bgp router-id 10.2.2.2

bgp log-neighbor-changes

neighbor AS10 peer-group

neighbor AS10 remote-as 10

neighbor AS10 update-source Loopback0

neighbor AS10 route-reflector-client

neighbor 10.1.1.1 peer-group AS10

neighbor 10.3.3.3 peer-group AS10

no auto-summary

router bgp 10

no synchronization

bgp router-id 10.3.3.3

bgp log-neighbor-changes

neighbor 10.2.2.2 remote-as 10

neighbor 10.2.2.2 update-source Loopback0

neighbor 172.16.34.4 remote-as 20

neighbor 172.16.36.6 remote-as 30

no auto-summary

interface FastEthernet0/0

ip ospf network point-to-point

ip ospf 1 area 0

interface Loopback0

ip ospf 1 area 0

interface FastEthernet0/0

ip ospf network point-to-point

ip ospf 1 area 0

interface Loopback0

ip ospf 1 area 0

R4#sh ip route ospf

20.0.0.0/8 is variably subnetted, 3 subnets, 2 masks

O 20.5.5.5/32 [110/2] via 20.1.45.5, 00:00:00, FastEthernet0/0

R4#ping 20.5.5.5 source loopback 0

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 20.5.5.5, timeout is 2 seconds:

Packet sent with a source address of 20.4.4.4

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 28/36/64 ms

router bgp 20

no synchronization

bgp router-id 20.4.4.4

bgp log-neighbor-changes

network 20.4.4.4 mask 255.255.255.255

neighbor 20.5.5.5 remote-as 20

neighbor 20.5.5.5 update-source Loopback0

neighbor 172.16.14.1 remote-as 10

neighbor 172.16.34.3 remote-as 10

neighbor 172.16.46.6 remote-as 30

no auto-summary

router bgp 20

no synchronization

bgp router-id 20.5.5.5

bgp log-neighbor-changes

neighbor 20.4.4.4 remote-as 20

neighbor 20.4.4.4 update-source Loopback0

neighbor 172.16.56.6 remote-as 30

no auto-summary

router bgp 30

no synchronization

bgp router-id 30.6.6.6

bgp log-neighbor-changes

neighbor 172.16.36.3 remote-as 10

neighbor 172.16.46.4 remote-as 20

neighbor 172.16.56.5 remote-as 20

neighbor 192.168.1.7 remote-as 65400

no auto-summary

router bgp 65400

no synchronization

bgp router-id 100.7.7.7

bgp log-neighbor-changes

neighbor 192.168.1.6 remote-as 30

no auto-summary

R2#show ip bgp summary

BGP router identifier 10.2.2.2, local AS number 10

BGP table version is 1, main routing table version 1

Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd

10.1.1.1 4 10 31 31 1 0 0 00:25:59 0

10.3.3.3 4 10 28 28 1 0 0 00:25:13 0

R6#show ip bgp summary

BGP router identifier 30.6.6.6, local AS number 30

BGP table version is 1, main routing table version 1

Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd

172.16.36.3 4 10 9 9 1 0 0 00:06:51 0

172.16.46.4 4 20 9 9 1 0 0 00:06:49 0

172.16.56.5 4 20 9 9 1 0 0 00:06:41 0

192.168.1.7 4 65400 29 29 1 0 0 00:01:22 0

Publique en BGP las loopbacks0 de los routers que participan en BGP
R2 y R3 deben publicar la red 23.0.0.0/24
R4 y R5 deben publicar la red 45.0.0.0/24

router bgp 10

network 23.0.0.0 mask 255.255.255.0

router bgp 10

network 23.0.0.0 mask 255.255.255.0

R3#show ip bgp

BGP table version is 4, local router ID is 10.3.3.3

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

*> 23.0.0.0/24 0.0.0.0 0 32768 i

* i 10.2.2.2 0 100 0 i

router bgp 20

network 45.0.0.0 mask 255.255.255.0

router bgp 20

network 45.0.0.0 mask 255.255.255.0

R5#show ip bgp regexp _$

BGP table version is 3, local router ID is 20.5.5.5

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

*> 45.0.0.0/24 0.0.0.0 0 32768 i

router bgp 10

network 10.1.1.1 mask 255.255.255.255

router bgp 10

network 10.2.2.2 mask 255.255.255.255

router bgp 10

network 10.3.3.3 mask 255.255.255.255

router bgp 20

network 20.4.4.4 mask 255.255.255.255

router bgp 20

network 20.5.5.5 mask 255.255.255.255

router bgp 30

network 30.6.6.6 mask 255.255.255.255

router bgp 65400

network 100.7.7.7 mask 255.255.255.255

R2#show ip bgp

BGP table version is 7, local router ID is 10.2.2.2

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,

r RIB-failure, S Stale

Network Next Hop Metric LocPrf Weight Path

r>i10.1.1.1/32 10.1.1.1 0 100 0 i

*> 10.2.2.2/32 0.0.0.0 0 32768 i

r>i10.3.3.3/32 10.3.3.3 0 100 0 i

* i20.4.4.4/32 172.16.14.4 0 100 0 20 i

* i 172.16.36.6 0 100 0 30 20 i

* i20.5.5.5/32 172.16.14.4 0 100 0 20 i

* i 172.16.36.6 0 100 0 30 20 i

* i23.0.0.0/24 10.3.3.3 0 100 0 i

*> 0.0.0.0 0 32768 i

* i30.6.6.6/32 172.16.14.4 0 100 0 20 30 i

* i 172.16.36.6 0 100 0 30 i

* i45.0.0.0/24 172.16.36.6 0 100 0 30 20 i

* i 172.16.14.4 0 100 0 20 i

* i100.7.7.7/32 172.16.14.4 0 100 0 20 30 65400 i

* i 172.16.36.6 0 100 0 30 65400 i

NEXT_HOP

Antes de que R2 pueda instalar las actualizaciones sobre cualquier red externa debemos tener en cuenta que los ASBRs publican las actualizaciones sin modificar el next-hop. Veamos la siguiente salida. Si observamos por ejemplo la red 60.0.0.0/24 veremos que R1 y R3 han publicado como next-hop las direcciones 172.16.14.4 y 172.16.36.3. R2 no sabe cómo alcanzar estas direcciones. Que podemos hacer para que R2 conozca estas direcciones? Redistribuirlas dentro de IGP, no recomendable o que cada ASBR se haga pasar como próximo salto. Veamos cómo.

router bgp 30

network 60.0.0.0 mask 255.255.255.0

R2#show ip bgp

BGP table version is 7, local router ID is 10.2.2.2

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>i10.1.1.1/32 10.1.1.1 0 100 0 i

*> 10.2.2.2/32 0.0.0.0 0 32768 i

r>i10.3.3.3/32 10.3.3.3 0 100 0 i

* i20.4.4.4/32 10.3.3.3 0 100 0 20 i

*>i 10.1.1.1 0 100 0 20 i

* i20.5.5.5/32 10.3.3.3 0 100 0 20 i

*>i 10.1.1.1 0 100 0 20 i

* i23.0.0.0/24 10.3.3.3 0 100 0 i

*> 0.0.0.0 0 32768 i

*>i30.6.6.6/32 10.3.3.3 0 100 0 30 i

* i45.0.0.0/24 10.3.3.3 0 100 0 20 i

*>i 10.1.1.1 0 100 0 20 i

*>i60.0.0.0/24 10.3.3.3 0 100 0 30 i

*>i100.7.7.7/32 10.3.3.3 0 100 0 30 65400 i

router bgp 10

neighbor 10.2.2.2 next-hop-self

router bgp 10

neighbor 10.2.2.2 next-hop-self

R2#show ip bgp

BGP table version is 16, local router ID is 10.2.2.2

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>i10.1.1.1/32 10.1.1.1 0 100 0 i

*> 10.2.2.2/32 0.0.0.0 0 32768 i

r>i10.3.3.3/32 10.3.3.3 0 100 0 i

*>i20.4.4.4/32 10.1.1.1 0 100 0 20 i

*>i20.5.5.5/32 10.1.1.1 0 100 0 20 i

* i23.0.0.0/24 10.3.3.3 0 100 0 i

*> 0.0.0.0 0 32768 i

*>i30.6.6.6/32 10.3.3.3 0 100 0 30 i

*>i45.0.0.0/24 10.1.1.1 0 100 0 20 i

* i60.0.0.0/24 10.1.1.1 0 100 0 20 30 i

*>i 10.3.3.3 0 100 0 30 i

*>i100.7.7.7/32 10.3.3.3 0 100 0 30 65400 i

WEIGHT

R4 debe acceder a las redes originadas en AS10 a través de R3. Utilice atributo Weight.

R4#show ip bgp regexp ^10$

BGP table version is 22, local router ID is 20.4.4.4

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

* 10.1.1.1/32 172.16.34.3 0 10 i

*> 172.16.14.1 0 0 10 i

* 10.2.2.2/32 172.16.34.3 0 10 i

*> 172.16.14.1 0 10 i

* 10.3.3.3/32 172.16.34.3 0 0 10 i

*> 172.16.14.1 0 10 i

* 23.0.0.0/24 172.16.34.3 0 0 10 i

*> 172.16.14.1 0 10 i

ip as-path access-list 5 permit ^10$

route-map PESO permit 10

match as-path 5

set weight 65535

route-map PESO permit 20

router bgp 20

neighbor 172.16.34.3 route-map PESO in

R4#show ip bgp regexp ^10$

BGP table version is 26, local router ID is 20.4.4.4

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

*> 10.1.1.1/32 172.16.34.3 65535 10 i

* 172.16.14.1 0 0 10 i

*> 10.2.2.2/32 172.16.34.3 65535 10 i

* 172.16.14.1 0 10 i

*> 10.3.3.3/32 172.16.34.3 0 65535 10 i

* 172.16.14.1 0 10 i

*> 23.0.0.0/24 172.16.34.3 0 65535 10 i

* 172.16.14.1 0 10 i

R4#traceroute 10.1.1.1 source loopback 0 probe 1

Type escape sequence to abort.

Tracing the route to 10.1.1.1

1 172.16.34.3 24 msec

2 10.1.23.2 116 msec

3 10.1.12.1 48 msec

LOCAL_PREFERENCE

En R5 crear y publicar la red 50.0.0.0/24.
AS10 debe acceder a esta red a través de R3. Utilizar atributo LP.

interface Loopback50

ip address 50.0.0.5 255.255.255.0

router bgp 20

network 50.0.0.0 mask 255.255.255.0

R2#show ip bgp regexp 20$

BGP table version is 24, local router ID is 10.2.2.2

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

* i20.4.4.4/32 10.3.3.3 0 100 0 20 i

*>i 10.1.1.1 0 100 0 20 i

* i20.5.5.5/32 10.3.3.3 0 100 0 20 i

*>i 10.1.1.1 0 100 0 20 i

* i45.0.0.0/24 10.3.3.3 0 100 0 20 i

*>i 10.1.1.1 0 100 0 20 i

*>i50.0.0.0/24 10.1.1.1 0 100 0 20 i

* i 10.3.3.3 0 100 0 20 i

access-list 1 permit 50.0.0.0

route-map LP permit 10

match ip address 1

set local-preference 101

route-map LP permit 20

router bgp 10

neighbor 172.16.34.4 route-map LP in

R2#show ip bgp regexp 20$

BGP table version is 25, local router ID is 10.2.2.2

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

* i20.4.4.4/32 10.3.3.3 0 100 0 20 i

*>i 10.1.1.1 0 100 0 20 i

* i20.5.5.5/32 10.3.3.3 0 100 0 20 i

*>i 10.1.1.1 0 100 0 20 i

* i45.0.0.0/24 10.3.3.3 0 100 0 20 i

*>i 10.1.1.1 0 100 0 20 i

*>i50.0.0.0/24 10.3.3.3 0 101 0 20 i

R1#show ip bgp regexp 20$

BGP table version is 25, local router ID is 10.1.1.1

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

*> 20.4.4.4/32 172.16.14.4 0 0 20 i

*> 20.5.5.5/32 172.16.14.4 0 20 i

*> 45.0.0.0/24 172.16.14.4 0 20 i

*>i50.0.0.0/24 10.3.3.3 0 101 0 20 i

* 172.16.14.4 0 20 i

AS_PATH

R4 debe crear y publicar la red 40.0.0.0/24.
R1 debe acceder a la red 40.0.0.0/24 a través de R3. Utilizar atributo AS_PATH

interface Loopback40

ip address 40.0.0.4 255.255.255.0

router bgp 20

network 40.0.0.0 mask 255.255.255.0

R1#show ip bgp regexp 20$

BGP table version is 29, local router ID is 10.1.1.1

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

*> 20.4.4.4/32 172.16.14.4 0 0 20 i

*> 20.5.5.5/32 172.16.14.4 0 20 i

* i40.0.0.0/24 10.3.3.3 0 100 0 20 i

*> 172.16.14.4 0 0 20 i

*> 45.0.0.0/24 172.16.14.4 0 20 i

*>i50.0.0.0/24 10.3.3.3 0 101 0 20 i

* 172.16.14.4 0 20 i

access-list 1 permit 40.0.0.0

route-map AS permit 10

match ip address 1

set as-path prepend 20 20 20 20

route-map AS permit 20

router bgp 20

neighbor 172.16.14.1 route-map AS out

R1#show ip bgp regexp 20$

BGP table version is 31, local router ID is 10.1.1.1

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

*> 20.4.4.4/32 172.16.14.4 0 0 20 i

*> 20.5.5.5/32 172.16.14.4 0 20 i

*>i40.0.0.0/24 10.3.3.3 0 100 0 20 i

* 172.16.14.4 0 0 20 20 20 20 20 i

*> 45.0.0.0/24 172.16.14.4 0 20 i

*>i50.0.0.0/24 10.3.3.3 0 101 0 20 i

* 172.16.14.4 0 20 i

MED

R4 y R5 deben publicar la red 45.0.0.0/24.
R6 debe acceder a la red 45.0.0.0/24 a través de R5. Utilice atributo MED

router bgp 20

neighbor 20.5.5.5 next-hop-self

router bgp 20

neighbor 20.4.4.4 next-hop-self

router bgp 20

network 45.0.0.0 mask 255.255.255.0

router bgp 20

network 45.0.0.0 mask 255.255.255.0

R6#show ip bgp regexp 20$

BGP table version is 13, local router ID is 30.6.6.6

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

* 20.4.4.4/32 172.16.36.3 0 10 20 i

*> 172.16.46.4 0 0 20 i

* 172.16.56.5 0 20 i

* 20.5.5.5/32 172.16.36.3 0 10 20 i

*> 172.16.46.4 0 20 i

* 172.16.56.5 0 0 20 i

* 40.0.0.0/24 172.16.36.3 0 10 20 i

*> 172.16.46.4 0 0 20 i

* 172.16.56.5 0 20 i

* 45.0.0.0/24 172.16.36.3 0 10 20 i

*> 172.16.46.4 0 0 20 i

* 172.16.56.5 0 0 20 i

* 50.0.0.0/24 172.16.36.3 0 10 20 i

*> 172.16.46.4 0 20 i

* 172.16.56.5 0 0 20 i

access-list 2 permit 45.0.0.0

route-map MED permit 10

match ip address 2

set metric 65535

route-map MED permit 20

router bgp 20

neighbor 172.16.46.6 route-map MED out

R6#show ip bgp regexp 20$

BGP table version is 14, local router ID is 30.6.6.6

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

* 20.4.4.4/32 172.16.36.3 0 10 20 i

*> 172.16.46.4 0 0 20 i

* 172.16.56.5 0 20 i

* 20.5.5.5/32 172.16.36.3 0 10 20 i

*> 172.16.46.4 0 20 i

* 172.16.56.5 0 0 20 i

* 40.0.0.0/24 172.16.36.3 0 10 20 i

*> 172.16.46.4 0 0 20 i

* 172.16.56.5 0 20 i

* 45.0.0.0/24 172.16.36.3 0 10 20 i

* 172.16.46.4 65535 0 20 i

*> 172.16.56.5 0 0 20 i

* 50.0.0.0/24 172.16.36.3 0 10 20 i

*> 172.16.46.4 0 20 i

* 172.16.56.5 0 0 20 i

AGGREGATE ADDRESS

R7 debe crear y publicar en BGP el rango de redes 100.0.0.0/24 a 100.0.7.0/24. Los demás routers solo deben ver el prefijo sumarizado.

interface Loopback100

ip address 100.0.1.7 255.255.255.0 secondary

ip address 100.0.2.7 255.255.255.0 secondary

ip address 100.0.3.7 255.255.255.0 secondary

ip address 100.0.4.7 255.255.255.0 secondary

ip address 100.0.5.7 255.255.255.0 secondary

ip address 100.0.6.7 255.255.255.0 secondary

ip address 100.0.7.7 255.255.255.0 secondary

ip address 100.0.0.7 255.255.255.0

R6#show ip bgp regexp 65400$

BGP table version is 23, local router ID is 30.6.6.6

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

*> 100.0.0.0/24 192.168.1.7 0 0 65400 i

*> 100.0.1.0/24 192.168.1.7 0 0 65400 i

*> 100.0.2.0/24 192.168.1.7 0 0 65400 i

*> 100.0.3.0/24 192.168.1.7 0 0 65400 i

*> 100.0.4.0/24 192.168.1.7 0 0 65400 i

*> 100.0.5.0/24 192.168.1.7 0 0 65400 i

*> 100.0.6.0/24 192.168.1.7 0 0 65400 i

*> 100.0.7.0/24 192.168.1.7 0 0 65400 i

*> 100.7.7.7/32 192.168.1.7 0 0 65400 i

router bgp 65400

aggregate-address 100.0.0.0 255.255.248.0

R6#show ip bgp regexp 65400$

BGP table version is 23, local router ID is 30.6.6.6

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

*> 100.0.0.0/24 192.168.1.7 0 0 65400 i

*> 100.0.0.0/21 192.168.1.7 0 0 65400 i

*> 100.0.1.0/24 192.168.1.7 0 0 65400 i

*> 100.0.2.0/24 192.168.1.7 0 0 65400 i

*> 100.0.3.0/24 192.168.1.7 0 0 65400 i

*> 100.0.4.0/24 192.168.1.7 0 0 65400 i

*> 100.0.5.0/24 192.168.1.7 0 0 65400 i

*> 100.0.6.0/24 192.168.1.7 0 0 65400 i

*> 100.0.7.0/24 192.168.1.7 0 0 65400 i

*> 100.7.7.7/32 192.168.1.7 0 0 65400 i

Por defecto BGP publica el resumen y las redes específicas, debemos incluir la palabra clave summary-only

router bgp 65400

aggregate-address 100.0.0.0 255.255.248.0 summary-only

R6#show ip bgp regexp 65400$

BGP table version is 51, local router ID is 30.6.6.6

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

*> 100.0.0.0/21 192.168.1.7 0 0 65400 i

*> 100.7.7.7/32 192.168.1.7 0 0 65400 i

Blog SP

sábado, 16 de marzo de 2013

Atributos BGP

Setup BGP

WEIGHT

LOCAL_PREFERENCE

AS_PATH

MED