C6807-XL-S6T-BUN VSS-SSO-NSF and Dual Active detection releated info require.

[Ayub]

Hello All,

I am going to configure 2 Cisco 6807 XL core switches in VSS.. My questions are:

1- I read alot that SSO is coming pre configured on 6807 XL ?

2- In my enviorment there is no requirement for routing protocols like OSPF-EIGRP etc its simply switching requirement, so do i really need to configure NSF parrarel with SSO for VSS ? if i didnt configure NSF what will be the impact ?

3- I have two 32 and 16 port fiber modules on each core switch, for Dual active detection (fast hello) can i use two links (one link from each fiber module on each switch) for fast hello between two core switches in port-channel ? if yes then what benifit i will get ?

4- On supervisor engine side can i use any port for VSL between two core switches ? 

Thanks.

[Reza Sharifi]

Hi,

1- I read alot that SSO is coming pre configured on 6807 XL ?

If you configure both switch as VSS, SSO will be configured for you. So, no need to worry about it.

2-  didnt configure NSF what will be the impact ?

Since you are not running any routing protocols, you do not need NSF and there will be no impact.

3- I have two 32 and 16 port fiber modules on each core switch, for Dual active detection (fast hello) can i use two links (one link from each fiber module on each switch) for fast hello between two core switches in port-channel ? if yes then what benifit i will get ?

For fast-hello, all you need is ONE 1gig or 10Gig connection between the 2 devices.  There is no need for 2 connections or port-channel, etc..

4- On supervisor engine side can i use any port for VSL between two core switches ? 

Yes.

HTH

[Ayub · Accepted solution]

Thanks for the reply..

1 -  So you mean if i configure both switches in VSS.. then SSO will come automatically ? or shall i use

# redundancy

# mode SSO

before VSS configuration ?

2 - For Dual Active Detection i read in Cisco configuration guide that best practices are ..

Dual-Active Detection Restrictions (Fast Hello)

For dual-active detection link redundancy, configure at least two ports per switch for dual-active detection. For module redundancy, the two ports can be on different switching modules in each chassis, and should be on different modules than the VSL, if feasible.

really there is no need for Dual-Active Detection link redundancy ? just like port channel for VSL..

suppose if i use 1GIG port ( e.g from16 port module ) from one switch and same to other side .. what if my 32 port up-link module physically goes down ? Here i am confused.. 

and last thing is ..

3- what is the port-channel recommendation for VSL link .. should i enable first VSS under port-channel and then enable physical ports for channel-group ? or there is no such recommendation

[Reza Sharifi · Accepted solution]

1 -  So you mean if i configure both switches in VSS.. then SSO will come automatically ? or shall i use

# redundancy

# mode SSO

Mode sso is mainly use when you have 2 interfaces in the same chassis with no VSS.  In your case you should be fine.

2 - For Dual Active Detection i read in Cisco configuration guide that best practices are ..

Dual-Active Detection Restrictions (Fast Hello)

For dual-active detection link redundancy, configure at least two ports per switch for dual-active detection. For module redundancy, the two ports can be on different switching modules in each chassis, and should be on different modules than the VSL, if feasible. 

really there is no need for Dual-Active Detection link redundancy ? just like port channel for VSL..

You can always have 2 ports per Cisco document for fast-hello, but I have always used one and it works without any issue. For VSL links, I recommend 2 physical ports in port-channels. 

suppose if i use 1GIG port ( e.g from16 port module ) from one switch and same to other side .. what if my 32 port up-link module physically goes down ? Here i am confused..

If the 32 port up-link module physically goes down, you will lose the fast-hello link but VSS will still work fine until you use a different port/module and bring up the fast-hello port again.

and last thing is ..

3- what is the port-channel recommendation for VSL link .. should i enable first VSS under port-channel and then enable physical ports for channel-group ? or there is no such recommendation

for this question, just follow the config guide:

https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Campus/VSS30dg/campusVSS_DG/VSS-dg_appa-configs.pdf

HTH