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vlan internal allocation


what is vlan internal allocation policy?

whats the use of it?

Cisco Employee

Re: vlan internal allocation

Hello Vishal,

The default of "vlan internal allocation policy ascending" allocates  internal VLANs starting at 1006 up to 4094. When "vlan internal  allocation policy descending" is configured internal VLANs are allocated  from 4094 down to 1006. Ultimately it all depends on how you assign  VLANs in the extended range. If you use VLANs starting are the lower side of the extended range, then you will need to  change the internal allocation policy to descending.

You can configure internal VLAN allocation to be from 1006 and up or from 4094 and down. The internal VLANs and user-configured VLANs share the 1006 to 4094 VLAN spaces. A "first come, first served" policy is used in allocating these spaces. The vlan internal allocation policy command allows you to configure the allocation direction of the internal VLAN.

During system bootup, the internal VLANs that are required for features in the startup-config file are allocated first. The user-configured VLANs in the startup-config file are configured next. If you configure a VLAN that conflicts with an existing internal VLAN, the VLAN that you configured is put into a nonoperational status until the internal VLAN is freed and becomes available.

After you enter the write mem command and the system reloads, the reconfigured allocation scheme is used by the port manager.



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