Este documento describe cómo configurar el switch de peer en los switches Nexus de Cisco serie 7000 para permitir que las conexiones de canal de puerto no virtual (que no sean vPC) equilibren la carga entre VLAN.
Cuando se habilita el switch peer, cada switch Nexus 7000 comparte un ID de puente virtual, que permite que ambos switches actúen como root para la VLAN. Para los dispositivos con una conexión a cada switch Nexus 7000 en el dominio vPC que no son capaces de canalizar puertos, la topología de capa 2 (L2) se basa en el protocolo de árbol de extensión (STP) para bloquear los enlaces redundantes. La función de switch peer permite que las configuraciones pseudo-STP permitan que las conexiones que no son de vPC equilibren la carga de los estados STP entre los dos switches Nexus 7000. Este documento explica en detalle la razón de las configuraciones pseudo-STP y cómo afectan a los links que no son vPC y vPC.
Una combinación de enlaces vPC y no vPC se denomina configuración híbrida.
Las direcciones MAC para cada switch utilizado en el ejemplo de configuración en este documento son:
Cisco recomienda que tenga conocimiento sobre estos temas:
La información de este documento se basa en los switches Nexus de Cisco serie 7000 con el módulo Supervisor 1.
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Este es un diagrama de red de una configuración híbrida sin par-switch habilitado. Ambos switches Nexus 7000 se configuran con una prioridad de 8192 para todas las VLAN. N7K-1 gana la elección del puente porque tiene el ID del puente inferior. Por lo tanto, espera que SW-1 bloquee el link de N7K-2. SW-2 se conecta a los switches Nexus 7000 a través de un vPC y se encuentra en estado de reenvío. SW-2 recibe las unidades de datos de protocolo de puente (BPDU) sólo del switch principal en el vPC, que es N7K-1 en este ejemplo.
SW-1# show span vlan 1VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 8193
Address 0024.986f.3b41
Cost 4
Port 295 (Ethernet2/39)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 0024.986f.3b44
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Eth2/39 Root FWD 4 128.295 P2p
Eth2/40 Altn BLK 4 128.296 P2p
SW-1# show span vlan 1 detail
VLAN0001 is executing the rstp compatible Spanning Tree protocol
Bridge Identifier has priority 32768, sysid 1, address 0024.986f.3b44
Configured hello time 2, max age 20, forward delay 15
Current root has priority 8193, address 0024.986f.3b41
Root port is 295 (Ethernet2/39), cost of root path is 4
Topology change flag not set, detected flag not set
Number of topology changes 4 last change occurred 0:29:13 ago
from Ethernet2/39
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15
Timers: hello 0, topology change 0, notification 0
Port 295 (Ethernet2/39) of VLAN0001 is root forwarding
Port path cost 4, Port priority 128, Port Identifier 128.295
Designated root has priority 8193, address 0024.986f.3b41
Designated bridge has priority 8193, address 0024.986f.3b41
Designated port id is 128.260, designated path cost 0, Topology change is set
Timers: message age 16, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
BPDU: sent 4, received 898
Port 296 (Ethernet2/40) of VLAN0001 is alternate blocking
Port path cost 4, Port priority 128, Port Identifier 128.296
Designated root has priority 8193, address 0024.986f.3b41
Designated bridge has priority 8193, address 0024.986f.3b42 <-- Although same priority,
Designated port id is 128.272, designated path cost 2 advertising Bridge ID is higher
Timers: message age 16, forward delay 0, hold 0 and therefore this link is BLK
Number of transitions to forwarding state: 2
Link type is point-to-point by default
BPDU: sent 6, received 895
Este es un diagrama de red de una configuración híbrida con el switch de par activado. Cuando se habilita el switch peer, cada switch Nexus 7000 comparte un ID de puente virtual que permite que ambos switches actúen como root para la VLAN. El enlace de par vPC siempre está en estado de reenvío y ejecuta L2 Gateway Interconnection Protocol (L2GIP) para evitar loops de conexión en puente.
Cada switch Nexus 7000 envía BPDU con un puente raíz identificado por el ID de puente virtual. En los links vPC, el ID de puente designado también utiliza el ID de puente virtual. Para los links que no son de vPC, el ID de puente designado es el ID de puente físico del switch Nexus 7000 correspondiente. Esto permite al switch que no es vPC (SW-1) tomar una decisión raíz basada en los anuncios de BPDU en lugar de en la prioridad de puerto.
Con el switch de peer habilitado, cada switch Nexus 7000 genera BPDU con el bridge raíz configurado en el ID de puente virtual y el bridge designado configurado en el ID de puente físico. Dado que las prioridades son las mismas, todas las conexiones que no son de vPC siempre se reenvían en el enlace conectado al switch Nexus 7000 con el ID de puente inferior (N7K-1 en este ejemplo) y bloquean los enlaces conectados al switch Nexus 7000 con el ID de puente más alto (N7K-2 en este ejemplo).
SW-1# show span vlan 1
VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 8193
Address 0023.04ee.be01
Cost 4
Port 295 (Ethernet2/39)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 0024.986f.3b44
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Eth2/39 Root FWD 4 128.295 P2p
Eth2/40 Altn BLK 4 128.296 P2p
SW-1# show span vlan 1 detail
VLAN0001 is executing the rstp compatible Spanning Tree protocol
Bridge Identifier has priority 32768, sysid 1, address 0024.986f.3b44
Configured hello time 2, max age 20, forward delay 15
Current root has priority 8193, address 0023.04ee.be01
Root port is 295 (Ethernet2/39), cost of root path is 4
Topology change flag not set, detected flag not set
Number of topology changes 6 last change occurred 0:25:38 ago
from Ethernet2/39
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15
Timers: hello 0, topology change 0, notification 0
Port 295 (Ethernet2/39) of VLAN0001 is root forwarding
Port path cost 4, Port priority 128, Port Identifier 128.295
Designated root has priority 8193, address 0023.04ee.be01 <---Root Bridge = virtual ID
Designated bridge has priority 8193, address 0024.986f.3b41 <---Designated Bridge ID = N7K-1
Designated port id is 128.260, designated path cost 0, Topology change is set
Timers: message age 16, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
BPDU: sent 4, received 2280
Port 296 (Ethernet2/40) of VLAN0001 is alternate blocking
Port path cost 4, Port priority 128, Port Identifier 128.296
Designated root has priority 8193, address 0023.04ee.be01 <---Root Bridge = virtual ID
Designated bridge has priority 8193, address 0024.986f.3b42 <---Designated Bridge ID = N7K-2
Designated port id is 128.272, designated path cost 0
Timers: message age 15, forward delay 0, hold 0
Number of transitions to forwarding state: 2
Link type is point-to-point by default
BPDU: sent 7, received 2278
Con el switch de peer habilitado, las conexiones vPC reciben BPDU con el puente raíz y el puente designado establecidos en el ID de puente virtual.
SW-2# show span vlan 1
VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 8193
Address 0023.04ee.be01
Cost 3
Port 4105 (port-channel10)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 0024.986f.3b43
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po10 Root FWD 3 128.4105 P2p
SW-2# show span vlan 1 detail
VLAN0001 is executing the rstp compatible Spanning Tree protocol
Bridge Identifier has priority 32768, sysid 1, address 0024.986f.3b43
Configured hello time 2, max age 20, forward delay 15
Current root has priority 8193, address 0023.04ee.be01
Root port is 4105 (port-channel10), cost of root path is 3
Topology change flag not set, detected flag not set
Number of topology changes 5 last change occurred 0:21:40 ago
from port-channel10
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15
Timers: hello 0, topology change 0, notification 0
Port 4105 (port-channel10) of VLAN0001 is root forwarding
Port path cost 3, Port priority 128, Port Identifier 128.4105
Designated root has priority 8193, address 0023.04ee.be01 <--- Virtual Bridge ID
Designated bridge has priority 8193, address 0023.04ee.be01 <--- Virtual Bridge ID
Designated port id is 128.4105, designated path cost 0, Topology change is set
Timers: message age 15, forward delay 0, hold 0
Number of transitions to forwarding state: 2
Link type is point-to-point by default
BPDU: sent 96, received 2804
En la configuración predeterminada del switch de peer, todas las VLAN del switch que no es vPC se reenvían en un único link. Para equilibrar la carga entre las VLAN, las prioridades designadas y raíz anunciadas pueden configurarse manualmente mediante el uso de configuraciones de información de pseduo del árbol de expansión. Cisco recomienda que la prioridad raíz en la información de pseduo sea inferior a la mejor prioridad del árbol de expansión para evitar las notificaciones de cambio de topología (TCN) en condiciones de failover. Las prioridades designadas se pueden equilibrar de carga entre los dos switches Nexus 7000 en el dominio vPC.
En este ejemplo, las prioridades del árbol de expansión global en ambos switches Nexus 7000 se han establecido en 8192. Bajo la pseudo-información, la prioridad raíz se ha configurado como 4096, que es menor que la mejor prioridad de 8192. Por lo tanto, el switch que participa con el switch de peer habilitado se convierte en la raíz para la VLAN. Para equilibrar la carga entre los dos switches, las prioridades designadas se alternan para VLAN 9 y VLAN 10. Para las conexiones que no son de vPC a SW-1, la VLAN 9 se reenvía en el link a N7K-1 y la VLAN 10 se reenvía en el link a N7K-2.
Para la VLAN 9, SW-1 ve la prioridad del puente de pseudo raíz y el ID del puente como el mismo valor de N7K-1 y N7K-2. Sin embargo, tanto N7K-1 como N7K-2 envían sus prioridades pseudo designadas configuradas. Por lo tanto, SW-1 ve la prioridad de puente designada de 8201 (8192 + 9) de N7K-1 y la prioridad de puente designada de 12297 (12288 + 9) de N7K-2; SW-1 elige el link hacia N7K-1 como el link de reenvío en la VLAN 9.
SW-1# show span vlan 9
VLAN0009
Spanning tree enabled protocol rstp
Root ID Priority 4105
Address 0023.04ee.be01
Cost 4
Port 295 (Ethernet2/39)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32777 (priority 32768 sys-id-ext 9)
Address 0024.986f.3b44
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Eth2/39 Root FWD 4 128.295 P2p
Eth2/40 Altn BLK 4 128.296 P2p
SW-1# show span vlan 9 detail
VLAN0009 is executing the rstp compatible Spanning Tree protocol
Bridge Identifier has priority 32768, sysid 9, address 0024.986f.3b44
Configured hello time 2, max age 20, forward delay 15
Current root has priority 4105, address 0023.04ee.be01
Root port is 295 (Ethernet2/39), cost of root path is 4
Topology change flag not set, detected flag not set
Number of topology changes 16 last change occurred 0:06:56 ago
from Ethernet2/39
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15
Timers: hello 0, topology change 0, notification 0
Port 295 (Ethernet2/39) of VLAN0009 is root forwarding
Port path cost 4, Port priority 128, Port Identifier 128.295
Designated root has priority 4105, address 0023.04ee.be01 <--- Root Virtual Bridge ID
Designated bridge has priority 8201, address 0024.986f.3b41 <--- Designated N7K-1, 8201
Designated port id is 128.260, designated path cost 0
Timers: message age 15, forward delay 0, hold 0
Number of transitions to forwarding state: 3
Link type is point-to-point by default
BPDU: sent 31, received 3486
Port 296 (Ethernet2/40) of VLAN0009 is alternate blocking
Port path cost 4, Port priority 128, Port Identifier 128.296
Designated root has priority 4105, address 0023.04ee.be01 <--- Root Virtual Bridge ID
Designated bridge has priority 12297, address 0024.986f.3b42 <--- Designated is N7K-2, 12297
Designated port id is 128.272, designated path cost 0
Timers: message age 15, forward delay 0, hold 0
Number of transitions to forwarding state: 4
Link type is point-to-point by default
BPDU: sent 31, received 3496
De manera similar para la VLAN 10, SW-1 ve la prioridad del puente de pseudo raíz y el ID del puente como el mismo valor de N7K-1 y N7K-2. De nuevo, tanto N7K-1 como N7K-2 envían sus prioridades pseudo designadas configuradas. Para VLAN 10, SW-1 ve la prioridad de puente designada de 12298 (12288 + 10) de N7K-1 y la prioridad de puente designada de 8202 (8192 + 10) de N7K-2; SW-1 elige el link hacia N7K-2 como el link de reenvío para VLAN 10. De esta manera, los switches no conectados a vPC pueden equilibrar la carga del estado de VLAN STP entre N7K-1 y N7K-2.
SW-1# show span vlan 10 detail
VLAN0010 is executing the rstp compatible Spanning Tree protocol
Bridge Identifier has priority 32768, sysid 10, address 0024.986f.3b44
Configured hello time 2, max age 20, forward delay 15
Current root has priority 4106, address 0023.04ee.be01
Root port is 296 (Ethernet2/40), cost of root path is 4
Topology change flag not set, detected flag not set
Number of topology changes 7 last change occurred 0:07:13 ago
from Ethernet2/40
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15
Timers: hello 0, topology change 0, notification 0
Port 295 (Ethernet2/39) of VLAN0010 is alternate blocking
Port path cost 4, Port priority 128, Port Identifier 128.295
Designated root has priority 4106, address 0023.04ee.be01 <--- Root Virtual Bridge ID
Designated bridge has priority 12298, address 0024.986f.3b41 <--- Designated N7K-1, 12298
Designated port id is 128.260, designated path cost 0, Topology change is set
Timers: message age 16, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
BPDU: sent 4, received 3497
Port 296 (Ethernet2/40) of VLAN0010 is root forwarding
Port path cost 4, Port priority 128, Port Identifier 128.296
Designated root has priority 4106, address 0023.04ee.be01 <--- Root Virtual Bridge ID
Designated bridge has priority 8202, address 0024.986f.3b42 <--- Designated N7K-2, 8202
Designated port id is 128.272, designated path cost 0
Timers: message age 16, forward delay 0, hold 0
Number of transitions to forwarding state: 3
Link type is point-to-point by default
BPDU: sent 10, received 3492
Para los links vPC, los campos raíz y designado utilizan la prioridad pseudo root y el ID de puente virtual, respectivamente.
SW-2# show span vlan 9
VLAN0009
Spanning tree enabled protocol rstp
Root ID Priority 4105
Address 0023.04ee.be01
Cost 3
Port 4105 (port-channel10)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32777 (priority 32768 sys-id-ext 9)
Address 0024.986f.3b43
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po10 Root FWD 3 128.4105 P2p
SW-2# show span vlan 10
VLAN0010
Spanning tree enabled protocol rstp
Root ID Priority 4106
Address 0023.04ee.be01
Cost 3
Port 4105 (port-channel10)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32778 (priority 32768 sys-id-ext 10)
Address 0024.986f.3b43
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po10 Root FWD 3 128.4105 P2p
SW-2#show span vlan 9 detail
VLAN0009 is executing the rstp compatible Spanning Tree protocol
Bridge Identifier has priority 32768, sysid 9, address 0024.986f.3b43
Configured hello time 2, max age 20, forward delay 15
Current root has priority 4105, address 0023.04ee.be01
Root port is 4105 (port-channel10), cost of root path is 3
Topology change flag not set, detected flag not set
Number of topology changes 12 last change occurred 0:04:29 ago
from port-channel10
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15
Timers: hello 0, topology change 0, notification 0
Port 4105 (port-channel10) of VLAN0009 is root forwarding
Port path cost 3, Port priority 128, Port Identifier 128.4105
Designated root has priority 4105, address 0023.04ee.be01 <--- Root Virtual Bridge ID
Designated bridge has priority 4105, address 0023.04ee.be01 <--- Root Virtual Bridge ID
Designated port id is 128.4105, designated path cost 0, Topology change is set
Timers: message age 15, forward delay 0, hold 0
Number of transitions to forwarding state: 2
Link type is point-to-point by default
BPDU: sent 119, received 4867
SW-2# show span vlan 10 detail
VLAN0010 is executing the rstp compatible Spanning Tree protocol
Bridge Identifier has priority 32768, sysid 10, address 0024.986f.3b43
Configured hello time 2, max age 20, forward delay 15
Current root has priority 4106, address 0023.04ee.be01
Root port is 4105 (port-channel10), cost of root path is 3
Topology change flag not set, detected flag not set
Number of topology changes 6 last change occurred 0:04:36 ago
from port-channel10
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15
Timers: hello 0, topology change 0, notification 0
Port 4105 (port-channel10) of VLAN0010 is root forwarding
Port path cost 3, Port priority 128, Port Identifier 128.4105
Designated root has priority 4106, address 0023.04ee.be01 <--- Root Virtual Bridge ID
Designated bridge has priority 4106, address 0023.04ee.be01 <--- Root Virtual Bridge ID
Designated port id is 128.4105, designated path cost 0, Topology change is set
Timers: message age 17, forward delay 0, hold 0
Number of transitions to forwarding state: 2
Link type is point-to-point by default
BPDU: sent 96, received 5179
Consulte Cisco bug ID CSCub74914: Prioridades Pseudo STP configuradas incorrectamente en links vPC en la configuración del switch peer
Actualmente, no hay un procedimiento de verificación disponible para esta configuración.
Actualmente, no hay información específica de troubleshooting disponible para esta configuración.
Revisión | Fecha de publicación | Comentarios |
---|---|---|
1.0 |
09-Aug-2013 |
Versión inicial |