VSS configuration Cisco Catalyst
24.09 2021 | by massimilianoUn sistema VSS opera via SSO (Stateful Switch-Over) tra peers attraverso le Supervisor Engine active e hot-standby ospitate nei rispettivi […]
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Un sistema VSS opera via SSO (Stateful Switch-Over) tra peers attraverso le Supervisor Engine active e hot-standby ospitate nei rispettivi chassis.
VSS Supervisor Engine active controlla le funzionalità layer 2 (switching) and layer 3 (routing) per entrambi gli chassis (single control-plane, single management point, dual active forwarding planes); Il piano di forwarding del traffico è performato da entrambi i peers VSS.
In caso di fault della Supervisor Engine active, quella in stato standby assume il suo ruolo (switchover)
VSL (Virtual Switch Link) è un collegamento tra i peers VSS per lo scambio di messaggi di controllo processati dalla Supervisor Engine active ma trasmessi e ricevuti su interface presenti nel peer VSS standby.
VSS opera in un contesto di Spanning Tree Protocol; il VSS standby redirige le BPDU STP via VSL verso il peer active.
Il STP bridge ID è un valore comune ed è calcolato sul MAC address chassis; non cambia a seguito di uno switchover peers.
LMP (Link Management Protocol) riferito come VSLP all’interno di un contesto VSL, verifica la bidirezionalità dei peers VSS, ne assicura il collegamento, trasmette e riceve keepalive (timers) per mantenere attivo e funzionante lo status VSL.
Il diagramma seguente evidenzia la configurazione fisica del C6807-XL in VSS:
Si riportano per completezza di informazioni alcuni output relativi ai LMP timers keepalive e virtual dual-active VSS:
VSS#show vslp lmp neighbors
Instance #1:
LMP neighbors
Peer Group info: # Groups: 1 (* => Preferred PG)
PG # MAC Switch Ctrl Interface Interfaces
—————————————————————
*1 002c.c825.0200 2 Te1/1/1 Te1/3/1, Te1/1/1
!
VSS#show vslp lmp timer
Instance #1:
LMP hello timer
Hello Tx (T4) ms Hello Rx (T5*) ms
Interface State Cfg Cur Rem Cfg Cur Rem
————————————————————————-
Te1/3/1 operational – 500 420 – 60000 59528
Te1/1/1 operational – 500 420 – 60000 59528
*T5 = min_rx * multiplier
Cfg : Configured Time
Cur : Current Time
Rem : Remaining Time
!
VSS#show switch virtual dual-active fast-hello
Fast-hello dual-active detection enabled: Yes
Fast-hello dual-active interfaces:
Port Local State Peer Port Remote State
—————————————————
Te1/1/2 Link up Te2/1/2 Link up
Te1/3/2 Link up Te2/3/2 Link up
LMP di defaul trasmette un valore di timer (T4) e riceve un min_rx pari a 500 msec; hold-timer conosciuto come (T5) deriva dal min_rx ed un valore di multiplier pari a 120; quindi di default il tempo limite per un peer VSL di detection è di 60 sec (1 minuto).
Cisco consiglia di mantenere i valori di default LMP (VSLP).
Configurazione VSS per i due peer switch:
VSS-1:
hostname VSS-SYSTEM
!
redundancy
main-cpu
auto-sync running-config
mode sso
!
switch virtual domain 106
switch mode virtual
switch 1 priority 110
mac-address use-virtual
Domain ID 106 config will take effect only
after the exec command ‘switch convert mode virtual’ is issued
switch1 local
exit
!
interface Port-channel1
description VSL Trunk
no switchport
no ip address
no platform qos channel-consistency
switch virtual link 1
!
interface TenGigabitEthernet1/1
description VSL Trunk
channel-group 1 mode on
!
interface TenGigabitEthernet1/2
description VSS Fast Hello
dual-active fast-hello
!
interface TenGigabitEthernet1/3
description VSL Trunk
channel-group 1 mode on
!
interface TenGigabitEthernet3/2
description VSS Fast Hello
dual-active fast-hello
!
!
switch convert mode virtual
This command will convert all interface names to naming convention “interface-type switch-number/slot/port”, save the running config to startup-config and reload the switch.
Do you want to proceed? [yes/no]: yes
Converting interface names
Building configuration…
[OK]
Saving converted configuration to bootflash: …
Destination filename [startup-config.converted_vs-2020xxxxxx-xxxxxx]?
AT THIS POINT SWITCH 1 WILL REBOOT…
VSS-2:
hostname VSS-SYSTEM
!
redundancy
main-cpu
auto-sync running-config
mode sso
!
switch virtual domain 106
switch mode virtual
switch 2 priority 90
mac-address use-virtual
Domain ID 106 config will take effect only
after the exec command ‘switch convert mode virtual’ is issued
switch2 local
exit
!
interface Port-channel2
description VSL Trunk
no switchport
no ip address
no platform qos channel-consistency
switch virtual link 2
!
interface TenGigabitEthernet1/1
description VSL Trunk
channel-group 2 mode on
!
interface TenGigabitEthernet/1/2
description VSS Fast Hello
dual-active fast-hello
!
interface TenGigabitEthernet3/1
description VSL Trunk
channel-group 2 mode on
!
interface TenGigabitEthernet3/2
description VSS Fast Hello
dual-active fast-hello
!
switch convert mode virtual
This command will convert all interface names to naming convention “interface-type switch-number/slot/port”, save the running config to startup-config and reload the switch.
Do you want to proceed? [yes/no]: yes
Converting interface names
Building configuration…
[OK]
Saving converted configuration to bootflash: …
Destination filename [startup-config.converted_vs-2020xxxxxx-xxxxxx]?
AT THIS POINT SWITCH 2 WILL REBOOT…
Config Finale VSS-SYSTEM:
switch virtual domain 106
switch mode virtual
switch 1 priority 110
switch 2 priority 90
mac-address use-virtual
!
redundancy
main-cpu
auto-sync running-config
mode sso
!
interface Port-channel1
description VSL Trunk
no switchport
no ip address
no platform qos channel-consistency
switch virtual link 1
!
interface Port-channel2
description VSL Trunk
no switchport
no ip address
no platform qos channel-consistency
switch virtual link 2
!
interface TenGigabitEthernet1/1/1
description VSL Trunk
no switchport
no ip address
no cdp enable
channel-group 1 mode on
!
interface TenGigabitEthernet1/1/2
description VSS Fast Hello
no switchport
no ip address
no cdp enable
dual-active fast-hello
!
interface TenGigabitEthernet1/3/1
description VSL Trunk
no switchport
no ip address
no cdp enable
channel-group 1 mode on
!
interface TenGigabitEthernet1/3/2
description VSS Fast Hello
no switchport
no ip address
no cdp enable
dual-active fast-hello
!
interface TenGigabitEthernet2/1/1
description VSL Trunk
no switchport
no ip address
no cdp enable
channel-group 2 mode on
!
interface TenGigabitEthernet2/1/2
description VSS Fast Hello
no switchport
no ip address
no cdp enable
dual-active fast-hello
!
interface TenGigabitEthernet2/3/1
description VSL Trunk
no switchport
no ip address
no cdp enable
channel-group 2 mode on
!
interface TenGigabitEthernet2/3/2
description VSS Fast Hello
no switchport
no ip address
no cdp enable
dual-active fast-hello
!