VSS configuration Cisco Catalyst

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VSS configuration Cisco Catalyst

24.09 2021 | by massimiliano

Un 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:

 

VSS SYSTEM

 

  

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

!

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