Switches, Hubs, and Modems

Re: no untagged confusion

 
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Cameron Stephens
Occasional Contributor

no untagged confusion

Hello, I come from a Cisco background where access ports and trunk ports are fairly straight forward to understand. I am now working at a company with a HP 5406zl which has tagged and untagged ports configured. Unfortunately the confusion lies with some VLANs having ports configured as 'no untagged'.

I havent been able to find any info by searching the forums as all it brings up is people's sample configs. Can anyone explain what this command accomplishes?

Thanks!
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Jeff Carrell
Honored Contributor
Solution

Re: no untagged confusion

quick info:

cisco speak = procurve (most industry) speak
--------------------------------------------
access port = untagged port
trunk port = tagged port (802.1Q)
etherchannel/FEC = trunk or LACP

now to the answer to your q:

the 'no untagged x' in vlan 1 means that the port has been moved untagged into a different vlan...

at factory defaults, all ports start out untagged in the default vlan - vlan 1...

hth...jeff
Cameron Stephens
Occasional Contributor

Re: no untagged confusion

Thanks again Jeff for your help.

Cameron
RicN
Valued Contributor

Re: no untagged confusion


I can also agree with you that the "no untagged" is strange because it is very unlogical.

Default all ports are in VLAN1, like:

untagged a1-a24

Then when you create, say, VLAN2 and move some port there then VLAN2 is:

untagged a10

and what VLAN1 in my opinion SHOULD look like:

untagged a1-a9,a11-a24

This information is "really" complete.

But, which makes it confusing is the "double information" now in VLAN1:

untagged a1-a9,a11-a24
no untagged a10

which means the same, but the second line really has no logical use, but for some reason automaticly included. It is only seen in VLAN1.
GrogiGiant
New Member

Re: no untagged confusion

This double information comes from the simple fact - what the running config really is. Once that is understood, you'll get why the switch adds the "no untagged" line there.

The running config is simply a list of CLI commands the switch would execute during boot time to configure itself. 

In the default state each port is assocaited with untagged VLAN 1. If you want to associate a different untagged VLAN to a port, that's easy - you'd execute untagged portnumber command - and this command would appear in your running config. But what if you don't want to associate any untagged VLAN to said port? The untagged VLAN 1 is automatically associated with it at boot, and you will not assign different VLAN to it later. You'd have to remove that association by executing no untagged portnumber.