8000 vlans on 7600 interface??

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Mar 3rd, 2008
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I am finding references to SPA's with support up to 8000 vlans with restriction of 4000 for dot1q. I can't find any reference on how to use the range up to 8000. Everything says support for it, but how? Is it a new encapsulation?



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mheusing Thu, 03/06/2008 - 17:37
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A Shared Port Adapter (SPA) can have several ports. So on two dot1Q ports with 4000 VLANs each, you could have 8000 VLANs in total.

The data sheets state: "Up to 8000 VLANs per SPA and subject to a limit of 4000 VLANs per port for 802.1q".

This does not mean a different encapsulation has been invented, afaik.

Hope this helps!

Regards, Martin

GREGORY GEE Fri, 03/07/2008 - 06:54
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Thanks, that does clarify things. Can you point be in the right direction for documentation on how to setup SPA and configure vlans in this manner? I'm just not clear on how to focus the search.



mheusing Fri, 03/07/2008 - 11:00
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Hi Greg,

There is no SPA specific document for interface/VLAN configuration to my knowledge. The SPA will be detected automatically and IOS will place the respective interfaces in IDB.

As such you just have to look for the interface configuration guide of your platform and IOS version. There you will get the information on how to configure VLAN subinterfaces.

Hope this helps! Please use the rating system.

Regards, Martin

william.caban Fri, 03/07/2008 - 11:46
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It is my understanding that the 4K, 8K, etc, additional VLANs are based in the ability of the SPA (an other interfaces) of being able to define a vlan or a group of vlans from an interface directly to a Provider VLAN using QinQ (dot1q-tunnel)

For example, in ATM+VLAN, take a look at the "bridge-domain" command where you can map a group of vlan to a single provider vlan using dot1q-tunnel:

bridge-domain vlan-id [access | dot1q | dot1q-tunnel] [ignore-bpdu-pid] | {pvst-tlv CE-vlan} [increment] [split-horizon]


A similar approach is used in EVC ES-20 where "you can have" 32K vlans... well the truth is that at the switch your maximum will be 4094 *but* at the interface level you will have the ability to "use them":





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