The short answer is that the 6500 platform spanning-tree scalability is limited by virtual ports and the complexity of your spanning-tree topology. If you only have a couple of trunks carrying all 4096 VLANs then you'll be fine. If you have a lot FastE ports trunking hundreds of VLANs then you will quickly run into the virtual port limits. The 12.2SXF release notes indicate the virtual port limits which can be checked against the "show vlan virtual-port" command output. The documentation isn't clear, but the 6500 spanning-tree limits are based upon virtual ports rather than logical ports (ex CatOS, 4500, ..). If you check that 12.2SXI release notes you'll see that Cisco included enhancements that increase the virtual port scalability numbers. Note, RST is listed as RPVST+ in the table.
http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SXF/native/release/notes/OL_4164.html#wp26366

Shine Joseph wrote:
Hi,

I searched in the archives if I could find the answer to my this query. =
The result was negative.

How many spanning-tree instances are possible in Rapid PVST+ and MST =
modes in Cisco 6500 series switches with Sup720?

The only documentation that I could see which says about total number of =
virtual ports per line card and total active logical ports. There is no =
reference to  number of instances.

The following netpro link mentions about 4096 instances, but this point =
is not validated.
http://forums.cisco.com/eforum/servlet/NetProf?page=3Dnetprof&forum=3DNet=
work%20Infrastructure&topic=3DLAN%2C%20Switching%20and%20Routing&topicID=3D=
.ee71a04&CommCmd=3DMB%3Fcmd%3Dpass_through%26location%3Doutline%40%5E1%40=
%40.2cc1484e/2#selected_message

Any links or pointers would be much appreciated.

Thanks in advance,
Shine
_______________________________________________
cisco-nsp mailing list  [email protected]
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/


--
==================================================================
Clinton Work
Airdrie, AB


_______________________________________________
cisco-nsp mailing list  [email protected]
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

Reply via email to