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ashirkar
Level 7
Level 7

 

Introduction

The Cisco Virtual Switching System is a clustering technology that pools two Cisco Catalyst 4500-E Series Switches with Cisco Catalyst Supervisor Engine 7-E or 7-LE or two Catalyst 4500-X Series Switches into a single virtual switch. In a VSS, the data plane of both clustered switches is active at the same time in both chassis. VSS members are connected by virtual switch links (VSLs) using standard Gigabit or 10 Gigabit Ethernet connections between the VSS members. VSLs can carry regular user traffic in addition to the control plane communication between the VSS members.

Physical vs Logical Topology in a VSS Configuration

 

vss.jpg

 

This document describes how to configure a virtual switching system (VSS) for the Catalyst 4500 series switch (Supervisor Engine 7-E, Supervisor Engine 7L-E).

Some key point to be remembered for Cisco 4500 VSS

1) Configuration/Capability Supported supervisors on Catalyst 4500-E: VSS support Supervisor Engine 7-E or 7-LE (identical pairs).For more information about hardware to support please refer 4500 VSS Hardware requirement

2) Software requirement: Cisco IOS XE 3.4.0SG and ROMMON IOS Version 15.0(1r) SG7 later released support VSS.(Also refer How to Upgrade Cisco 4500 SUP7-E & Sup7L-E ROMMON To support VSS).

3)license requirement : 

To know more on license requirement refer "Release Notes for the Catalyst 4500E Series Switch"

Feature

LAN Base

IP Base

Enterprise Service

  • Virtual Switching System (VSS

 

No

Yes
(SUP7E only)

Yes

  • Support for Layer 3 MEC—VSS with Layer 3 Multichassis EtherChannel (MEC) at the aggregation layer

  • Support for VSLP Fast Hello—With VSLP Fast Hello, the Catalyst 4500-X configured for VSS can now connect Access Switches that do not support the ePAgP protocol.

  • Support for VSL Encryption

  • Support for Asymmetrix chassis

No

Yes (SUP7E)

No (SUP7LE)

Yes (SUP7E)

Yes (SUP7LE)

 

For information about Software Activation Licensing please refer Cisco Catalyst 4500E Supervisor 7-E and 7L-E and Cisco Catalyst 4500-X Series Software Activation Licensing Deployment Guide.

4) Single-sup cross-chassis VSS support: Yes.

5) Quad-sup VSS configuration with in-chassis redundant sups: In-chassis redundant sups in rommon mode with active uplinks.

6) It also supports 10 Gigabit Ethernet Virtual Switch Link (VSL) and 1 Gigabit Ethernet VSL.

7) SSO and nonstop forwarding (NSF) must be configured on each switch. If a VSS does not meet the requirements for SSO redundancy; it will be incapable of establishing a relationship with the peer switch. Catalyst 4500/4500-X series switches' VSS does not support route processor redundancy (RPR) mode.

Prerequisite

Before configuring VSS on Cisco 4500 please verify hardware and software requirement.

SW1#sh ver | in IOS
Cisco IOS Software, IOS-XE Software, Catalyst 4500 L3 Switch Software (cat4500e-UNIVERSAL-M), Version 03.04.00.SG RELEASE SOFTWARE (fc3)
Cisco IOS-XE software, Copyright (c) 2005-2010, 2012 by cisco Systems, Inc.
All rights reserved. Certain components of Cisco IOS-XE software are
documentation or "License Notice" file accompanying the IOS-XE software,
or the applicable URL provided on the flyer accompanying the IOS-XE

SW1#sh ver | in ROM
ROM: 15.0(1r)SG7
System returned to ROM by power-on 

SW1#sh license image levels 
Module name       Image level Priority Configured Valid license
--------------------------------------------------------------------
WS-X45-SUP7-E     entservices  1         YES        entservices            
                  ipbase       2         NO         ipbase                
                  lanbase      3         NO         lanbase  
 
Module Name     Role           Current Level     Reboot Level
--------------------------------------------------------------------
WS-X45-SUP7-E  Active         entservices       entservices

 

SW2#sh ver | in IOS
Cisco IOS Software, IOS-XE Software, Catalyst 4500 L3 Switch Software (cat4500e-UNIVERSAL-M), Version 03.04.00.SG RELEASE SOFTWARE (fc3)
Cisco IOS-XE software, Copyright (c) 2005-2010, 2012 by cisco Systems, Inc.
All rights reserved. Certain components of Cisco IOS-XE software are
documentation or "License Notice" file accompanying the IOS-XE software,
or the applicable URL provided on the flyer accompanying the IOS-XE

SW2#sh ver | in ROM
ROM: 15.0(1r)SG7
System returned to ROM by power-on

SW2#sh license image levels
Module name       Image level Priority Configured Valid license
--------------------------------------------------------------------
WS-X45-SUP7-E     entservices  1         YES        entservices            
                  ipbase       2         NO         ipbase                
                  lanbase      3         NO         lanbase 

Module Name     Role           Current Level     Reboot Level
--------------------------------------------------------------------
WS-X45-SUP7-E   Active        entservices       entservices

 

Configuration Steps

STEP1: Assigning Virtual Switch Domain and Switch Numbers

First you have to configure the same virtual switch domain number on both switches of the VSS. The virtual switch domain is a number between 1 and 255.After domain number you must configure one switch to be switch number 1 and the other switch to be switch number 2.

SW1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
SW1(config)#switch virtual domain 10
Domain ID 10 config will take effect only
after the exec command 'switch convert mode virtual' is issued
SW1(config-vs-domain)#switch 1
SW1(config-vs-domain)#exit
SW1(config)#

 

SW2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
SW2(config)#switch virtual domain 10
Domain ID 10 config will take effect only
after the exec command 'switch convert mode virtual' is issued
SW2(config-vs-domain)#switch 2
SW2(config-vs-domain)#exit
SW2(config)#

 

STEP2: Configuring VSL Port Channel

Then you need to configure VSL with a unique port channel on each switch. During the conversion, the VSS configures both port channels on the VSS Active switch. If the VSS Standby switch VSL port channel number has been configured for another use, the VSS comes up in RPR mode. To avoid this situation, check that both port channel numbers are available on both of the switches.

SW1(config)#int port-channel 5
SW1(config-if)#switchport
SW1(config-if)#switch virtual link 1
SW1(config-if)#no shut
SW1(config-if)#exit
*Jan 24 05:19:57.092: %SPANTREE-6-PORTDEL_ALL_VLANS: Port-channel5 deleted from all Vlans

 

SW2(config)#int port-channel 10
SW2(config-if)#switchport
SW2(config-if)#switch virtual link 2
SW2(config-if)#no shut
SW2(config-if)#exit
SW2(config)#
*Jan 24 05:14:17.273: %SPANTREE-6-PORTDEL_ALL_VLANS: Port-channel10 deleted from all Vlans

 

STEP3: configure the VSL ports

You need to add the VSL physical ports to the port channel. In the following example, interfaces Gigabit Ethernet 7/3 and 7/4 on Switch 1 are connected to interfaces Gigabit Ethernet 4/45 and 4/46 on Switch 2.

SW1(config)#int range gig7/3 - 4
SW1(config-if-range)#switchport mode trunk
SW1(config-if-range)#channel-group 5 mode on
WARNING: Interface GigabitEthernet7/3 placed in restricted config mode. All extraneous configs removed!
WARNING: Interface GigabitEthernet7/4 placed in restricted config mode. All extraneous configs removed!
SW1(config-if-range)#exit

 

SW2(config)#int range gig4/45 - 46
SW2(config-if-range)#switchport mode trunk
SW2(config-if-range)#channel-group 10 mode on
WARNING: Interface GigabitEthernet4/45 placed in restricted config mode. All extraneous configs removed!
WARNING: Interface GigabitEthernet4/46 placed in restricted config mode. All extraneous configs removed!
SW2(config-if-range)#exit

 

Note: Once the interfaces are put into VSL port-channel with “channel-group" command, then the interfaces goes into “notconnect” status. Interface status will show UP, but the line protocol will be down. The interface will be in UP/down (not connect) status, till the switch is rebooted in step 4.

STEP4: Converting the Switch to Virtual Switch Mode:

You need to enter the “switch convert mode virtual” command on Switch 1 for Converting to Virtual Switch Mode .After you enter this command it will prompted to confirm the action. Enter yes. The system creates a converted configuration file, and saves the file to the bootflash:

SW1#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...
Compressed configuration from 6551 bytes to 2893 bytes[OK]
Saving converted configuration to bootflash: ...
Destination filename [startup-config.converted_vs-20130124-062921]?
Please stand by while rebooting the system...
Restarting system. 

Rommon (G) Signature verification PASSED  
Rommon (P) Signature verification PASSED  
FPGA   (P) Signature verification PASSED

Similarly you need to enter the “switch convert mode virtual” command on Switch 2 for converting to Virtual Switch Mode.

 

SW2#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...
Compressed configuration from 6027 bytes to 2774 bytes[OK]
Saving converted configuration to bootflash: ...
Destination filename [startup-config.converted_vs-20130124-052526]?
Please stand by while rebooting the system...
Restarting system. 

Rommon (G) Signature verification PASSED  

Rommon (P) Signature verification PASSED  

FPGA   (P) Signature verification PASSED 

************************************************************
*                                                          *
* Welcome to Rom Monitor for   WS-X45-SUP7-E System.       *
* Copyright (c) 2008-2012 by Cisco Systems, Inc.           *
* All rights reserved.                                     *
*                                                          *
************************************************************

 

After you confirm the above commands on both switches, the running configuration is automatically saved as the startup configuration and the switch reboots. After the reboot, the switch is in virtual switch mode, so you must specify interfaces with three identifiers (switch/module/port).

When switches are being converted to VSS, you should not set them to ignore startup-config. If done, the switch can be enabled to parse the startup-config at the rommon prompt. Ignoring startup-config in VSS mode causes a switch to boot in a semi-VSS mode, which can only be corrected by a reboot and by enabling the parsing of startup-config.

Verification

1) To displays the virtual switch domain number, and the switch number and role for each of the switches you can use “show switch virtual” command.

SW1#sh switch virtual 

Executing the command on VSS member switch role = VSS Active, id = 1 

Switch mode                  : Virtual Switch
Virtual switch domain number : 10
Local switch number          : 1
Local switch operational role: Virtual Switch Active
Peer switch number           : 2
Peer switch operational role : Virtual Switch Standby 

Executing the command on VSS member switch role = VSS Standby, id = 2  

Switch mode                  : Virtual Switch
Virtual switch domain number : 10
Local switch number          : 2
Local switch operational role: Virtual Switch Standby
Peer switch number           : 1
Peer switch operational role : Virtual Switch Active

 

2) Once both switches cluster in single virtual switch, you will only have Active switch console and your Standby switch console appears as follow:

SW2-standby> 
Standby console disabled

3) To displays the role, switch number, and priority for each of the switch in the VSS use “show switch virtual role” command.

SW1#sh switch virtual role 

Executing the command on VSS member switch role = VSS Active, id = 1 

RRP information for Instance 1 

--------------------------------------------------------------------
Valid Flags   Peer     Preferred Reserved
               Count     Peer       Peer  

--------------------------------------------------------------------
TRUE   V       1           1         1  

Switch Switch Status Preempt       Priority Role     Local   Remote
       Number         Oper(Conf)   Oper(Conf)         SID     SID
--------------------------------------------------------------------
LOCAL   1     UP     FALSE(N )     100(100) ACTIVE   0       0
REMOTE  2     UP     FALSE(N )     100(100) STANDBY 6834   6152  

Peer 0 represents the local switch  

Flags : V - Valid
In dual-active recovery mode: No  

Executing the command on VSS member switch role = VSS Standby, id = 2 

RRP information for Instance 2  

--------------------------------------------------------------------
Valid Flags   Peer     Preferred Reserved
               Count     Peer       Peer  

--------------------------------------------------------------------
TRUE    V       1           1         1  

Switch Switch Status Preempt       Priority Role     Local   Remote
       Number         Oper(Conf)   Oper(Conf)         SID     SID
--------------------------------------------------------------------
LOCAL   2     UP     FALSE(N )     100(100) STANDBY  0       0
REMOTE  1     UP     FALSE(N )     100(100) ACTIVE   6152   6834 

Peer 0 represents the local switch

Flags : V - Valid
In dual-active recovery mode: No

 

4) To Displays information about the VSL use “show switch virtual link” command.

SW1#sh switch virtual link  

Executing the command on VSS member switch role = VSS Active, id = 1 

VSL Status : UP
VSL Uptime : 3 minutes
VSL Control Link : Gi1/7/4  

Executing the command on VSS member switch role = VSS Standby, id = 2 

VSL Status : UP
VSL Uptime : 3 minutes
VSL Control Link : Gi2/4/45

 

5) You can also verify information about the VSL port channel using “show switch virtual link port-channel”command.

SW1#sh switch virtual link port-channel 

Executing the command on VSS member switch role = VSS Active, id = 1 

Flags: D - down       P - bundled in port-channel
       I - stand-alone s - suspended
       H - Hot-standby (LACP only)
       R - Layer3     S - Layer2
       U - in use     N - not in use, no aggregation
       f - failed to allocate aggregator         

       M - not in use, no aggregation due to minimum links not met
       m - not in use, port not aggregated due to minimum links not met
       u - unsuitable for bundling
       d - default port  
       
       w - waiting to be aggregated  

Group Port-channel Protocol   Ports
------+-------------+-----------+-------------------
5     Po5(SU)          -       Gi1/7/3(P) Gi1/7/4(P)
10    Po10(SU)         -       Gi2/4/45(P) Gi2/4/46(P)  

Executing the command on VSS member switch role = VSS Standby, id = 2  

Flags: D - down       P - bundled in port-channel
       I - stand-alone s - suspended
       H - Hot-standby (LACP only)
       R - Layer3     S - Layer2
       U - in use     N - not in use, no aggregation
       f - failed to allocate aggregator         
       
       M - not in use, no aggregation due to minimum links not met
       m - not in use, port not aggregated due to minimum links not met
       u - unsuitable for bundling
       d - default port  
       
       w - waiting to be aggregated 

Group Port-channel Protocol   Ports
------+-------------+-----------+-------------------
5     Po5(SU)          -       Gi1/7/3(P) Gi1/7/4(P)
10    Po10(SU)         -       Gi2/4/45(P) Gi2/4/46(P) 

SW1#

Reference

Comments
sepideh.ta
Level 1
Level 1

Hi

Is it possiable to define three switch 4500 for VSS technology?

tanks

ashirkar
Level 7
Level 7

Hello Sisily

Up to two physical Cisco switches allow operating as a VSS. You can also go through Virtual Switching System (VSS) Q&A for 6500.

Regards

Ashish Shirkar

sepideh.ta
Level 1
Level 1

hi Ashish

tanks alot for quick response.

Sisily

Feichti
Level 1
Level 1

Hi Ashish

I have got a question to:

5) Quad-sup VSS configuration with in-chassis redundant sups: In-chassis redundant sups in rommon mode with active uplinks.

I have got running 2x 4510R+E with 4x SUP7. But wen the active or standy sup failes the second sup in the chasis boots in standalone mode but not in the vss mode .

Is there anywhere a manual how to config a 4500 VSS with Quad Sup?

Kind Regards

Tobias

Shahid Mohsin
Level 1
Level 1

Hi

we have vrrp,hsrp,glbp redundancy protocol then why we use VSS.

ashirkar
Level 7
Level 7

Hello Shahid,

Please check Virtual Switching System (VSS) Q&A for your question and let me know if you have any doubt

Regards,

Ashish Shirkar

(Community Manager-NI)

Shahid Mohsin
Level 1
Level 1

Hi

Thanks for your  support but tellme this vss run for one instance for all vlan (or) single instance for single vlan,And vss does  support loadbalancing.

And I want BGP study meterial hope you help me..

Once again Thank you,

aurio.tenorio
Level 1
Level 1

My implementation, which is identical, is crashing. Not recommended.

4510R+E, Sup 7-e IOS 3.4.0 15.1.2, ROM SG7 (SG10).

Some ideas?

ashirkar
Level 7
Level 7

Hello Aurio,

Thanks for your feedback,

To run VSS on 4500 not only Software requirement must match also hardware should be check.

Older generation line cards are not supported in  the 3.4.0SG release with the VSS feature. These include all line cards  starting with the 'WS-X45xy' id, and lower. 'WS-X44xy' and 'WS-X42xy'  are some other examples of unsupported line cards. Please remove these  line cards from your system when converting from standalone to VSS mode.

Please also refer this document for your hardward requirement before configuring VSS on your  4500 .

Configuring VSS

Regrads,

Ashish Shirkar

(Community Manager-NI)

ashirkar
Level 7
Level 7

Hello Tobias,

Thanks for your feedback ,

Please refer Quad-Supervisor (In-chassis Standby Supervisor Engine) Support section of VSS configuration guide of 4500 .

Hope it help

Regrads,

Ashish Shirkar

(Community Manager-NI)

ashirkar
Level 7
Level 7

Hello Shahid,

Please refer Fundamentals of Cisco Virtual Switching System video to understand about VSS.

Hope it will clear you about VSS

Regrads,

Ashish Shirkar

(Community Manager-NI)

giovanni.costantini
Community Member

Dear Sirs,

   I need a clarification about that:

We have 2x 4503, with this configuration:

  • 1x ws-x45-sup7l-e
  • 1x ws-x4748-rj45-e

Can I use 10/100/1000 ports on the 4748 line card to create the VSL instead of the supervisor card ports?

this is because I want to use the supervisor port to perform optical fiber uplinks toward a couple of switch.

thanks you very much,

Giovanni

aurio.tenorio
Level 1
Level 1

Dear Ashish,

There is a bug in one variant of implementation, which causes the crashes of the switch 2. If you want, we can talk more about it.

I tried two variants, one always crashes. The other one, which is similar to the one described here, really works.

In the crashing implementation, parameters different are:

- priority configured in switch 1 to 200

- supervisor 10 gig ports used. This combination crashes. Try it.

This version crashed many, many times.

I then changed. Removed priority of switch 1, and moved the port-channels to gig ports, then, as magical, it worked.

There is a bug for sure, wanting Cisco admit or not.

I still recommend caution.

zulfiquar.l
Community Member

Hey Ashish.

Nice & usefull document. Will be a good reference during my implementation.

Cheers,

Zulfiquar.

s.ranjane
Level 1
Level 1

Hi Ashish,

Good reference for deployment of VSS...

way to go...

Regards,

Sachin Ranjane

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