VSS - Why use SXIx?

[avanzaadmin]

Hi folks

I'm about to implement a VSS using 6509-E. It's a fresh installation and I've got the hardware up and running and have started to read up on the two IOS versions. Some people say "always use the latest version" and some say "use the next newest version just to be sure". I will not need support for FWSM or IDSM, is there some reason for me to stick with SXH rather than SXI3? Both SXH and SXI are labeled as "OK" by Cisco and I see no apparent killer feature in SXI.

Regards

Fredrik Hofgren

[Ganesh Hariharan]

Hi folks
I'm
about to implement a VSS using 6509-E. It's a fresh installation and
I've got the hardware up and running and have started to read up on the
two IOS versions. Some people say "always use the latest version" and
some say "use the next newest version just to be sure". I will not need
support for FWSM or IDSM, is there some reason for me to stick with SXH
rather than SXI3? Both SXH and SXI are labeled as "OK" by Cisco and I
see no apparent killer feature in SXI.
Regards
Fredrik Hofgren

Hi Fredril Hofgren,

Cisco IOS Release 12.2(33)SXH supports a fast software upgrade (FSU) of the VSS using RPR. Cisco IOS Release 12.2(33)SXI and later releases support an enhanced fast software upgrade (eFSU) of the VSS using SSO.

Check out the below link for more information !!

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/vss.html#wp1053927

Hope to Help !!

Ganesh.H

Remember to rate the helpful post

[avanzaadmin]

That's one difference, thank you. How about stability issues, should SXI be considered a more stable release than SXH or is it the other way?

/Fredrik

[Reza Sharifi]

Hi Fredrik,

If you do side by side comparison using the feature navigator, SXI has a lot more features specially when it comes to IPv6 and MPLS then SXH.  Besides most future features ie dual sup support seem to be going into SXI.  I have always used SXI and there have been several nasty bugs in earlier releases ie SXI1 and 2, but since SXI2a and now SXI3 the image for VSS seems to be a lot more stable.

FYI, SXI4 is due to be released in June.

HTH

Reza

[Ganesh Hariharan]

That's one difference, thank you.
How about stability issues, should SXI be considered a more stable
release than SXH or is it the other way?
/Fredrik

SXI2 had at least one very significant bug (which can cause the chassis to crash because of a memory leak bug).  SXI has bugs with EIGRP tagging (amongst other things).  I wouldn’t typically recommend the SXH train as there are a lot of features that can be gained by going to the SXI train.  SXI2a offers a ton of features not found with SXI1, so if unicast IPv6, MPLS, etc. is needed, look at SXI2a and/or SXI3.

I can’t stress enough that the proper steps be followed when selecting an IOS image as should be taken without VSS.  Look at the release notes, search the bug toolkit, etc.

Hope to Help !!

Ganesh.H

Remember to rate the helpful post

[Hitesh Vinzoda]

I would suggest SXI as i had these code deployed on 8 nos. of 6509's with FWSM installed and also gives me luxury of ISSU In service software upgrades

Also all service modules are supported on it. as far as the bugs are concern you have to see that more you use the features more you are likely to hit a bug.

Give a try to bug toolkit to see high severity bugs or open bugs for the code.

PS : i got a nod from TAC to upgrade the switches to SXI.

HTH

Hitesh Vinzoda

[agugger]

Hi Fredrik

Our Motivation to change was the number of possibles MEC:

512 at SXI only 128 on all earlier see bellow:

Configuring Multichassis EtherChannels

Configure multichassis EtherChannels (MECs) as you would for a regular EtherChannel. The VSS will recognize that the EtherChannel is an MEC when ports from both chassis are added to the EtherChannel. You can verify the MEC configuration by entering the show etherchannel command.

One VSS supports a maximum of 512 port channels.

Note Releases earlier than Cisco IOS Release 12.2(33)SXI support a maximum of 128 port channels.

Found at:

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/vss.html#Configuring_Multichassis_EtherChannels

Regards

Andy