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New Member


The scenario is as follows:

Wap is connect to port 18 on the switch,and when i check the WAP gui for the forwarding state it is showing me blocking.

The error which i see on pot 18 on the switch is

Sep 19 03:01:04.640: %LINK-3-UPDOWN: Interface FastEthernet0/18, changed state to up

*Sep 19 03:01:07.208: %SPANTREE_VLAN_SW-2-MAX_INSTANCE: Platform limit of 64 STP instances exceeded.

No instance created for VLAN961 (port Fa0/18).

*Sep 19 03:01:08.220: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/18, changed stat

e to up

PVST is running on the switch and i have command

spanning-tree extend system-id

no spanning-tree vlan 961

on the switch.

Could any one figure out what the problem is.

Because as far as i think since no STP is running for vlan 961 i should not be getting this error.



Some switches can't run more than 64 STP instances. Is this a 2900 series switch. Are you running VTP where the server may be advertising more than 64 VLANs to this switch? See the workaround below.

Error Message SPANTREE_VLAN_SW-2-MAX_INSTANCE: Platform limit of [dec] STP instances

exceeded. No instance created for [chars] (port [chars]).

Explanation This message means that the number of currently-active VLAN spanning tree instances has reached a platform-specific limit. No additional VLAN instances will be created until the number of existing instances drops below the platform limit. This message shows the smallest number of those VLANs that are unable to have STP instances created.

Recommended Action Reduce the number of currently active spanning-tree instances by either disabling some of the currently active spanning-tree instances or by deleting the VLANs associated with currently active spanning-tree instances. You need to manually enable the spanning-trees that could not be created due to limited STP instances.



New Member


Ya what you are saying is true ,but if you see i am not running spanning tree for 961,and more over the port 18 on switch is in vlan 500

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