Verificación de la Conectividad de Extremo a Extremo a través de un SP de Segment Routing
Contenido
Introducción
Este documento describe el proceso para verificar la conectividad de extremo a extremo a través de un proveedor de servicios (SP) de ruteo de segmentos con el software Cisco IOS®XR.
Prerequisites
Requirements
Cisco recomienda que tenga conocimiento sobre estos temas:
- Conocimiento del ruteo IP básico
- Conocimiento de la línea de comandos de Cisco IOS y Cisco IOS XR
Componentes Utilizados
La información que contiene este documento se basa en las siguientes versiones de software y hardware.
- Router con software Cisco IOS XR
- Router con software Cisco IOS
La información que contiene este documento se creó a partir de los dispositivos en un ambiente de laboratorio específico. Todos los dispositivos que se utilizan en este documento se pusieron en funcionamiento con una configuración verificada (predeterminada). Si tiene una red en vivo, asegúrese de entender el posible impacto de cualquier comando.
Antecedentes
El propósito de este documento es demostrar la configuración básica para crear una nube de Segment Routing y cómo verificar la conectividad de extremo a extremo en los routers Cisco IOS XR.
Topología
Topología de red
Verificación inicial
Configuración de BGP
CE-1
Loopback55 simula el lado LAN del router CE-1. Puede anunciar este prefijo a través de eBGP al vecino PE-1:
CE-1#show run | section r b
router bgp 65535
bgp router-id 10.1.1.1
bgp log-neighbor-changes
redistribute connected
redistribute eigrp 10
neighbor 172.16.20.2 remote-as 8181
CE-1#show ip bgp neighbors 172.16.20.2 advertised-routes
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, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
t secondary path,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
*> 10.1.1.1/32 0.0.0.0 0 32768 ?
*> 10.11.11.11/32 192.168.1.1 10880 32768 ?
*> 10.55.55.55/32 0.0.0.0 0 32768 ?
*> 172.16.20.0/30 0.0.0.0 0 32768 ?
*> 192.168.1.0 0.0.0.0 0 32768 ?
Total number of prefixes 5PE-1
Este router recibió el prefijo 10.55.55.55/32 y tiene conectividad, ahora puede anunciarlo en la nube del proveedor de servicios:
RP/0/RP0/CPU0:PE-1#show run vrf
Fri Jan 27 15:07:10.465 UTC
vrf Yellow
address-family ipv4 unicast
import route-target
200:200
!
export route-target
200:200
!
RP/0/RP0/CPU0:PE-1#show run router bgp
Fri Jan 27 14:54:33.488 UTC
router bgp 8181
bgp router-id 10.2.2.2
address-family ipv4 unicast
!
address-family vpnv4 unicast
!
neighbor 10.3.3.3
remote-as 8181
update-source Loopback0
address-family vpnv4 unicast
route-policy PASS in
route-policy PASS out
!
!
vrf Yellow
rd 200:200
address-family ipv4 unicast
!
neighbor 172.16.20.1
remote-as 65535
address-family ipv4 unicast
route-policy PASS in
route-policy PASS out
as-override
!
RP/0/RP0/CPU0:PE-1#show bgp vrf Yellow ipv4 unicast neighbors 172.16.20.1 routes
Fri Jan 27 14:54:48.433 UTC
BGP VRF Yellow, state: Active
BGP Route Distinguisher: 200:200
VRF ID: 0x60000001
BGP router identifier 10.2.2.2, local AS number 8181
Non-stop routing is enabled
BGP table state: Active
Table ID: 0xe0000001 RD version: 73
BGP main routing table version 73
BGP NSR Initial initsync version 2 (Reached)
BGP NSR/ISSU Sync-Group versions 0/0
Status codes: s suppressed, d damped, h history, * valid, > best
i - internal, r RIB-failure, S stale, N Nexthop-discard
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 200:200 (default for vrf Yellow)
*> 10.1.1.1/32 172.16.20.1 0 0 65535 ?
*> 10.11.11.11/32 172.16.20.1 10880 0 65535 ?
*> 10.55.55.55/32 172.16.20.1 0 0 65535 ?
*> 172.16.20.0/30 172.16.20.1 0 0 65535 ?
*> 192.168.1.0/24 172.16.20.1 0 0 65535 ?
Processed 5 prefixes, 5 paths
RP/0/RP0/CPU0:PE-1#ping vrf Yellow 10.55.55.55
Fri Jan 27 14:55:06.077 UTC
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.55.55.55, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/5/7 msCE-2
Loopback66 simula el lado LAN del router CE-2. De manera similar a CE-1, este router anuncia el prefijo vía eBGP al router vecino PE-2.
CE-2#show run | section r b
router bgp 65535
bgp router-id 10.5.5.5
bgp log-neighbor-changes
redistribute connected
redistribute eigrp 10
neighbor 172.16.50.1 remote-as 8181
CE-2#show ip bgp neighbors 172.16.50.1 advertised-routes
BGP table version is 15, local router ID is 10.5.5.5
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
t secondary path,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
*> 10.5.5.5/32 0.0.0.0 0 32768 ?
*> 10.22.22.22/32 192.168.4.1 10880 32768 ?
*> 10.66.66.66/32 0.0.0.0 0 32768 ?
*> 172.16.50.0/30 0.0.0.0 0 32768 ?
*> 192.168.4.0 0.0.0.0 0 32768 ?
Total number of prefixes 5PE-2
Este router recibió el prefijo 10.66.66.66/32 y ahora puede anunciarse en la nube del proveedor de servicios:
RP/0/RP0/CPU0:PE-2#show run vrf
Fri Jan 27 15:07:51.117 UTC
vrf Yellow
address-family ipv4 unicast
import route-target
200:200
!
export route-target
200:200
!
RP/0/RP0/CPU0:PE-2#show run router bgp
Fri Jan 27 14:59:56.957 UTC
router bgp 8181
bgp router-id 10.4.4.4
address-family ipv4 unicast
!
address-family vpnv4 unicast
!
neighbor 10.3.3.3
remote-as 8181
update-source Loopback0
address-family vpnv4 unicast
route-policy PASS in
route-policy PASS out
!
!
vrf Yellow
rd 200:200
address-family ipv4 unicast
!
neighbor 172.16.50.2
remote-as 65535
address-family ipv4 unicast
route-policy PASS in
route-policy PASS out
as-override
!
RP/0/RP0/CPU0:PE-2#show bgp vrf Yellow ipv4 unicast neighbors 172.16.50.2 routes
Fri Jan 27 15:00:10.383 UTC
BGP VRF Yellow, state: Active
BGP Route Distinguisher: 200:200
VRF ID: 0x60000001
BGP router identifier 10.4.4.4, local AS number 8181
Non-stop routing is enabled
BGP table state: Active
Table ID: 0xe0000001 RD version: 64
BGP main routing table version 64
BGP NSR Initial initsync version 2 (Reached)
BGP NSR/ISSU Sync-Group versions 0/0
Status codes: s suppressed, d damped, h history, * valid, > best
i - internal, r RIB-failure, S stale, N Nexthop-discard
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 200:200 (default for vrf Yellow)
*> 10.5.5.5/32 172.16.50.2 0 0 65535 ?
*> 10.22.22.22/32 172.16.50.2 10880 0 65535 ?
*> 10.66.66.66/32 172.16.50.2 0 0 65535 ?
*> 172.16.50.0/30 172.16.50.2 0 0 65535 ?
*> 192.168.4.0/24 172.16.50.2 0 0 65535 ?
Processed 5 prefixes, 5 paths
RP/0/RP0/CPU0:PE-2#ping vrf Yellow 10.66.66.66
Fri Jan 27 15:00:26.020 UTC
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.66.66.66, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 3/26/120 msEstado de información de enrutamiento de PE-1, proveedor y PE-2
Para esta demostración, OSPF se configura como IGP e iBGP.
PE-1
El vecino OSPF está ACTIVO y la sesión iBGP a 10.3.3.3 que es Reflector de Ruta.
RP/0/RP0/CPU0:PE-1#show run router ospf
Fri Jan 27 15:09:23.910 UTC
router ospf 1
router-id 10.2.2.2
area 0
!
interface GigabitEthernet0/0/0/1
!
!
!
RP/0/RP0/CPU0:PE-1#show ospf neighbor
Fri Jan 27 15:09:31.435 UTC
* Indicates MADJ interface
# Indicates Neighbor awaiting BFD session up
Neighbors for OSPF 1
Neighbor ID Pri State Dead Time Address Interface
10.3.3.3 1 FULL/BDR 00:00:37 172.16.30.2 GigabitEthernet0/0/0/1
Neighbor is up for 16:59:30
Total neighbor count: 1
RP/0/RP0/CPU0:PE-1#show bgp vpnv4 unicast summary
Fri Jan 27 15:09:37.760 UTC
BGP router identifier 10.2.2.2, local AS number 8181
BGP generic scan interval 60 secs
Non-stop routing is enabled
BGP table state: Active
Table ID: 0x0 RD version: 0
BGP main routing table version 73
BGP NSR Initial initsync version 2 (Reached)
BGP NSR/ISSU Sync-Group versions 0/0
BGP scan interval 60 secs
BGP is operating in STANDALONE mode.
Process RcvTblVer bRIB/RIB LabelVer ImportVer SendTblVer StandbyVer
Speaker 73 73 73 73 73 0
Neighbor Spk AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down St/PfxRcd
10.3.3.3 0 8181 1010 997 73 0 0 16:24:45 5Router del proveedor
En este dispositivo podemos confirmar que actúa como reflector de ruta y que la sesión IBGP se establece con los vecinos 10.2.2.2 y 10.4.4.4
RP/0/RP0/CPU0:Provider#show run router ospf
Fri Jan 27 15:19:33.250 UTC
router ospf 1
router-id 10.3.3.3
area 0
!
interface GigabitEthernet0/0/0/1
!
interface GigabitEthernet0/0/0/2
!
RP/0/RP0/CPU0:Provider#show run router bgp
Fri Jan 27 15:11:08.321 UTC
router bgp 8181
bgp router-id 10.3.3.3
address-family ipv4 unicast
!
address-family vpnv4 unicast
!
neighbor-group IBGP
remote-as 8181
update-source Loopback0
!
neighbor 10.2.2.2
use neighbor-group IBGP
address-family vpnv4 unicast
route-policy PASS in
route-reflector-client
route-policy PASS out
next-hop-self
!
!
neighbor 10.4.4.4
use neighbor-group IBGP
address-family vpnv4 unicast
route-policy PASS in
route-reflector-client
route-policy PASS out
next-hop-self
!
RP/0/RP0/CPU0:Provider#show bgp vpnv4 unicast summary
Fri Jan 27 15:11:19.263 UTC
BGP router identifier 10.3.3.3, local AS number 8181
BGP generic scan interval 60 secs
Non-stop routing is enabled
BGP table state: Active
Table ID: 0x0 RD version: 0
BGP main routing table version 25
BGP NSR Initial initsync version 1 (Reached)
BGP NSR/ISSU Sync-Group versions 0/0
BGP scan interval 60 secs
BGP is operating in STANDALONE mode.
Process RcvTblVer bRIB/RIB LabelVer ImportVer SendTblVer StandbyVer
Speaker 25 25 25 25 25 0
Neighbor Spk AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down St/PfxRcd
10.2.2.2 0 8181 998 1011 25 0 0 16:26:27 5
10.4.4.4 0 8181 997 1009 25 0 0 16:24:25 5PE-2
El vecino OSPF está activo y la sesión IBGP a 10.3.3.3 es el Reflector de Ruta.
RP/0/RP0/CPU0:PE-2#show run router ospf
Fri Jan 27 15:12:47.741 UTC
router ospf 1
router-id 10.4.4.4
area 0
!
interface GigabitEthernet0/0/0/2
!
RP/0/RP0/CPU0:PE-2#show ospf neighbor
Fri Jan 27 15:12:55.229 UTC
* Indicates MADJ interface
# Indicates Neighbor awaiting BFD session up
Neighbors for OSPF 1
Neighbor ID Pri State Dead Time Address Interface
10.3.3.3 1 FULL/DR 00:00:35 172.16.40.1 GigabitEthernet0/0/0/2
Neighbor is up for 17:01:21
Total neighbor count: 1
RP/0/RP0/CPU0:PE-2#show bgp vpnv4 unicast summary
Fri Jan 27 15:13:01.911 UTC
BGP router identifier 10.4.4.4, local AS number 8181
BGP generic scan interval 60 secs
Non-stop routing is enabled
BGP table state: Active
Table ID: 0x0 RD version: 0
BGP main routing table version 64
BGP NSR Initial initsync version 2 (Reached)
BGP NSR/ISSU Sync-Group versions 0/0
BGP scan interval 60 secs
BGP is operating in STANDALONE mode.
Process RcvTblVer bRIB/RIB LabelVer ImportVer SendTblVer StandbyVer
Speaker 64 64 64 64 64 0
Neighbor Spk AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down St/PfxRcd
10.3.3.3 0 8181 1011 998 64 0 0 16:26:08 5
RP/0/RP0/CPU0:PE-2#ping 10.2.2.2 source loopback0
Fri Jan 27 15:13:09.728 UTC
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.2.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 9/21/67 ms
RP/0/RP0/CPU0:PE-2#ping 10.3.3.3 source loopback0
Fri Jan 27 15:13:16.696 UTC
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.3.3.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 5/6/7 msConfiguración de Segment Routing
PE-1
RP/0/RP0/CPU0:PE-1#show run router ospf
Fri Jan 27 16:15:56.479 UTC
router ospf 1
router-id 10.2.2.2
segment-routing mpls
area 0
segment-routing mpls
interface Loopback0
prefix-sid index 15
! Proveedor
RP/0/RP0/CPU0:Provider#show run router ospf
Fri Jan 27 16:17:09.471 UTC
router ospf 1
router-id 10.3.3.3
segment-routing mpls
area 0
segment-routing mpls
interface Loopback0
prefix-sid index 16
!PE-2
RP/0/RP0/CPU0:PE-2#show run router ospf
Fri Jan 27 16:18:11.090 UTC
router ospf 1
router-id 10.4.4.4
segment-routing mpls
area 0
segment-routing mpls
interface Loopback0
prefix-sid index 17
!
Verificaciones finales
CE-1 puede alcanzar la interfaz loopback66 ubicada en el router CE-2. El siguiente resultado de Traceroute muestra que el paquete toma la trayectoria del switch de etiqueta cuando está destinado al prefijo 10.66.66.66. También se puede observar que la etiqueta utiliza el prefijo-sid 16017 cuando pasa a través del router PE-2:
CE-1#ping 10.66.66.66 source loopback0 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10.66.66.66, timeout is 2 seconds: Packet sent with a source address of 10.1.1.1 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 9/13/32 ms CE-1#traceroute 10.66.66.66 source loopback0 Type escape sequence to abort. Tracing the route to 10.66.66.66 VRF info: (vrf in name/id, vrf out name/id) 1 172.16.20.2 6 msec 5 msec 5 msec 2 172.16.30.2 [MPLS: Labels 16017/24003 Exp 0] 12 msec 13 msec 16 msec 3 172.16.40.2 [MPLS: Label 24003 Exp 0] 15 msec 13 msec 12 msec 4 172.16.50.2 [AS 8181] 13 msec 11 msec *
Dado que la configuración no utilizó la opción absolute, las etiquetas comenzaron en valores 16000 y agregaron el prefijo-sid configurado para Segment Routing.
RP/0/RP0/CPU0:PE-1#show cef 10.3.3.3/32
Fri Jan 27 21:32:42.813 UTC
10.3.3.3/32, version 43, labeled SR, internal 0x1000001 0x8110 (ptr 0xe3f6a00) [1], 0x600 (0xe593918), 0xa20 (0xee6e4b8)
Updated Jan 26 23:21:30.314
remote adjacency to GigabitEthernet0/0/0/1
Prefix Len 32, traffic index 0, precedence n/a, priority 1
gateway array (0xe3fbda8) reference count 3, flags 0x68, source rib (7), 0 backups
[3 type 4 flags 0x8401 (0xeeb1648) ext 0x0 (0x0)]
LW-LDI[type=1, refc=1, ptr=0xe593918, sh-ldi=0xeeb1648]
gateway array update type-time 1 Jan 26 23:21:30.314
LDI Update time Jan 26 23:21:30.315
LW-LDI-TS Jan 26 23:21:30.315
via 172.16.30.2/32, GigabitEthernet0/0/0/1, 8 dependencies, weight 0, class 0 [flags 0x0]
path-idx 0 NHID 0x0 [0xf427148 0xf4271e0]
next hop 172.16.30.2/32
remote adjacency
local label 16016 labels imposed {ImplNull}
Load distribution: 0 (refcount 3)
Hash OK Interface Address
0 Y GigabitEthernet0/0/0/1 remote
RP/0/RP0/CPU0:PE-1#show cef 10.4.4.4/32
Fri Jan 27 21:29:36.990 UTC
10.4.4.4/32, version 45, labeled SR, internal 0x1000001 0x8110 (ptr 0xe3f65c0) [1], 0x600 (0xe593e70), 0xa28 (0xee6e508)
Updated Jan 26 23:21:47.181
remote adjacency to GigabitEthernet0/0/0/1
Prefix Len 32, traffic index 0, precedence n/a, priority 1
gateway array (0xe3fbe90) reference count 3, flags 0x68, source rib (7), 0 backups
[2 type 5 flags 0x8401 (0xeeb16a8) ext 0x0 (0x0)]
LW-LDI[type=5, refc=3, ptr=0xe593e70, sh-ldi=0xeeb16a8]
gateway array update type-time 1 Jan 26 23:21:47.182
LDI Update time Jan 26 23:21:47.182
LW-LDI-TS Jan 26 23:21:47.182
via 172.16.30.2/32, GigabitEthernet0/0/0/1, 6 dependencies, weight 0, class 0 [flags 0x0]
path-idx 0 NHID 0x0 [0xf4271e0 0x0]
next hop 172.16.30.2/32
remote adjacency
local label 16017 labels imposed {16017}
Load distribution: 0 (refcount 2)
Hash OK Interface Address
0 Y GigabitEthernet0/0/0/1 remote Desde el otro lado, CE-2 también puede alcanzar el loopback55 ubicado en el router CE-1:
CE-2#ping 10.55.55.55 source loopback66
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.55.55.55, timeout is 2 seconds:
Packet sent with a source address of 10.66.66.66
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 11/12/15 ms
CE-2#traceroute 10.55.55.55 source loopback66
Type escape sequence to abort.
Tracing the route to 10.55.55.55
VRF info: (vrf in name/id, vrf out name/id)
1 172.16.50.1 6 msec 5 msec 4 msec
2 172.16.40.1 [MPLS: Labels 16015/24003 Exp 0] 9 msec 16 msec 10 msec
3 172.16.30.1 [MPLS: Label 24003 Exp 0] 10 msec 13 msec 8 msec
4 172.16.20.1 [AS 8181] 11 msec 7 msec * Etiquetas MPLS
En la siguiente salida podemos confirmar que las etiquetas de ruteo de segmentos se utilizan para conmutar el tráfico de extremo a extremo.
RP/0/RP0/CPU0:PE-1#show mpls forwarding
Fri Jan 27 20:32:13.697 UTC
Local Outgoing Prefix Outgoing Next Hop Bytes
Label Label or ID Interface Switched
------ ----------- ------------------ ------------ --------------- ------------
16016 Pop SR Pfx (idx 16) Gi0/0/0/1 172.16.30.2 126880
16017 16017 SR Pfx (idx 17) Gi0/0/0/1 172.16.30.2 17292
24000 Pop SR Adj (idx 0) Gi0/0/0/1 172.16.30.2 0
24001 Aggregate 172.16.20.0/30[V] Yellow 11384
24002 Unlabelled 192.168.1.0/24[V] Gi0/0/0/0 172.16.20.1 0
24003 Unlabelled 10.55.55.55/32[V] Gi0/0/0/0 172.16.20.1 0
24004 Unlabelled 10.11.11.11/32[V] Gi0/0/0/0 172.16.20.1 0
24005 Unlabelled 10.1.1.1/32[V] Gi0/0/0/0 172.16.20.1 0 RP/0/RP0/CPU0:Provider#show mpls forwarding Fri Jan 27 20:33:14.878 UTC Local Outgoing Prefix Outgoing Next Hop Bytes Label Label or ID Interface Switched ------ ----------- ------------------ ------------ --------------- ------------ 16015 Pop SR Pfx (idx 15) Gi0/0/0/1 172.16.30.1 151687 16017 Pop SR Pfx (idx 17) Gi0/0/0/2 172.16.40.2 147701 24000 Pop SR Adj (idx 0) Gi0/0/0/1 172.16.30.1 0 24001 Pop SR Adj (idx 0) Gi0/0/0/2 172.16.40.2 0
RP/0/RP0/CPU0:PE-2#show mpls forwarding
Fri Jan 27 20:33:49.201 UTC
Local Outgoing Prefix Outgoing Next Hop Bytes
Label Label or ID Interface Switched
------ ----------- ------------------ ------------ --------------- ------------
16015 16015 SR Pfx (idx 15) Gi0/0/0/2 172.16.40.1 25304
16016 Pop SR Pfx (idx 16) Gi0/0/0/2 172.16.40.1 128619
24000 Pop SR Adj (idx 0) Gi0/0/0/2 172.16.40.1 0
24001 Aggregate 172.16.50.0/30[V] Yellow 1200
24002 Unlabelled 192.168.4.0/24[V] Gi0/0/0/3 172.16.50.2 0
24003 Unlabelled 10.66.66.66/32[V] Gi0/0/0/3 172.16.50.2 0
24004 Unlabelled 10.5.5.5/32[V] Gi0/0/0/3 172.16.50.2 0
24005 Unlabelled 10.22.22.22/32[V] Gi0/0/0/3 172.16.50.2 0 Historial de revisiones
| Revisión | Fecha de publicación | Comentarios |
|---|---|---|
1.0 |
30-Jan-2023 |
Versión inicial |
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