Redundancy on Cisco Switch 6509

[sidcracker]

Hello,

This is just a quick question on understanding the redundancy features on the 6509 Switch. If we configure the switch using the following commands, would it configure high availability so that it auto syncs commands between the active and secondary 6500's

redundancy

main-cpu

  auto-sync running-config

mode sso

Do we still need to configure HSRP now that we have added this?

Thanks

[Thotsaphon Lueangwattanaphong · Accepted solution]

Hi,

   The following commands are used for a redundant supervisor engine on the chassis.

!

redundancy

main-cpu

  auto-sync running-config

mode sso

!

     If you have 2 chassises and want to do Active/Active or Active/Standby. You may think of HSRP , GLBP or VSS(If hardware supported).

   Ref HSRP:

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps9336/product_data_sheet0900aecd806ed759.html

   Ref VSS :

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps9336/product_data_sheet0900aecd806ed759.html

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps9336/prod_qas0900aecd806ed74b.html

HTH,

Toshi

[Joseph W. Doherty]

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Posting

As the others have already noted, using a virtual gateway protocol (HSRP, etc.) normally is only used when there's more than one chassis.  If you have a pair of 6500s that support VSS, then you wouldn't need a virtual gateway, just as you don't need it on a single chassis.

On the subject of SSO, which is a L2 redundancy features when there are two supervisors in the same 6500 chassis, if you're also routing on the 6500 chassis you may want to also enable NSF (if supported).

NSF:

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SXF/native/configuration/guide/nsfsso.html

Nonstop Forwarding with Stateful Switchover on the Cisco Catalyst 6500

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/prod_white_paper0900aecd801c5cd7.html

[Giuseppe Larosa · Accepted solution]

Hello Sidcracker,

>> Do we still need to configure HSRP now that we have added this?

HSRP can be still useful if you have two core / distribution switches but it is a different matter then SSO.

SSO builds a tight relationship between the two supervisors in a C6509 chassis. SSO messages are not exposed to outside world.

HSRP provides first hop redundancy: a VIP that can  be used by clients in a connected Vlan to reach the other IP subnets.

if you have only one C6509 box with no companion node (even of a different model) you don't need HSRP.

In old times in dual routing mode DRM an HSRP group encompassing both MSFCs on two boxes was used in some cases.

Now, we use SRM ( single routing mode) and only one MSFC speaks with outside world even with SSO enabled

Edit:

as noted by Toshi if you build a VSS pair you don't need HSRP or other FHRP like VRRP or GLBP on the connected client Vlans.

Hope to help

Giuseppe

[sidcracker]

Thanks Toshi and Giuseppe