VLAN IDs in the Extended Range

Routing & Switching
1

So I have run across Cisco documentation that states the Extended range IDs can be numbered from 1006 to 4094, but have also run across Cisco documentation that states the range goes from 1006 to 4096! Here is what I have learned in the process of working towards CCNP R&S: the VLAN ID field has 12 bits in it. Two to the twelfth power = 4096 and that would be the total number of VLAN IDs that SHOULD be available. Accounting for VLAN ID 0 and 4095 not being usable, that makes the viable range from 1 - 4094, and the extended range should be 1006 - 4094. So why the discrepancy between several Cisco documents that list both ranges as viable? I cannot seem to find the answer anywhere, originally thinking that the document I was looking at had a typo. When I discovered other documents stating the same range (1006-4096) AND finding yet other documents stating 1006-4094 I became truly perplexed. Can someone explain to me what the issue might be please?

2

Hello Brad

Your explanation is correct, the range of VLAN IDs for extended VLANs should indeed be 1006-4094. Doing a small search for this topic in Cisco documentation, all of the documents I found stated this correct range. I believe that the majority of Cisco documentation gets this right, and the documents you found that show an incorrect range are the exception, even if you’ve seen it more than once.

I hope this has been helpful!

Laz

3

Yes, thank you Laz. I firmly believe that my explanation is correct but here are two documents that state otherwise (just for clarification that I am not crazy!):

Thanks!

Brad

4

Hi Brad

Thanks for sharing that. I’m amazed that Cisco didn’t catch that, and it’s on two documents too! It’s good you pointed it out for anyone else who is wondering as well…

Thanks once again!

Laz