It depends on the SDM template in use.  You can use the following to check
but 1024 is the default.
This output is from a 3560
Cat1#show sdm prefer ?
  access              Access bias
  default             Default bias
  dual-ipv4-and-ipv6  Support both IPv4 and IPv6
  ipe                 IPe bias
  routing             Unicast bias
  vlan                VLAN bias
  |                   Output modifiers
  <cr>
Cat1#show sdm prefer 
 The current template is "desktop default" template.
 The selected template optimizes the resources in
 the switch to support this level of features for
 8 routed interfaces and 1024 VLANs. 
  number of unicast mac addresses:                  6K
  number of IPv4 IGMP groups + multicast routes:    1K
  number of IPv4 unicast routes:                    8K
    number of directly-connected IPv4 hosts:        6K
    number of indirect IPv4 routes:                 2K
  number of IPv4 policy based routing aces:         0
  number of IPv4/MAC qos aces:                      0.5K
  number of IPv4/MAC security aces:                 1K
 
Cat1#
Regards,
 
Tyson Scott - CCIE #13513 R&S, Security, and SP
Technical Instructor - IPexpert, Inc.
Mailto: tscott_at_ipexpert.com
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-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
manoj nanda
Sent: Tuesday, February 09, 2010 9:03 PM
To: CCIE Groupstudy
Subject: SPT question
Folks:I am wandering regarding the maximum number of  per vlan spaning tree
instances  supported while runnig RSTP on a cisco switch say 2900 series!!
Any help!
thanks
Manoj
Blogs and organic groups at http://www.ccie.net
Received on Tue Feb 09 2010 - 22:15:52 ART
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