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Management traffic over native VLAN and double-tagging concern on MS switches

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Here to help

Management traffic over native VLAN and double-tagging concern on MS switches

I've recently added some new MS-225-48FP switches to the dashboard and noticed that within the "LAN IP" settings pane of the switches, I'm unable to save any changes without specifying a VLAN ID in the VLAN field.

If I leave the field blank and click Save it states "VLAN required".

 

VLAN Required.png

 

If I remember correctly, it used to be the case that you could leave this field blank. Is anyone aware of a development change with this?

 

I'm concerned about the possibility of 'double-tagging' occurring when specifying a VLAN ID there. I've been advised that if I want a switch to be set with a management IP address in the subnet corresponding to the native VLAN used on trunk links between switches, I must leave the VLAN field in the LAN IP settings pane (management interface)  blank. Apparently, if I were to specify the native VLAN's VLAN ID in that field it will result in  traffic being double-tagged?

 

If we are now forced to specify a VLAN in the LAN IP pane, presumably all dashboard traffic cannot flow over the native VLAN on uplink trunk ports (given it will be 'tagged' traffic) and you must specify a VLAN ID in that LAN IP pane that is different to the native VLAN's VLAN ID?

5 REPLIES 5
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Kind of a big deal

Re: Management traffic over native VLAN and double-tagging concern on MS switches

Yeh that's odd. I seem to remember leaving it blank in the past too. Maybe try making the VLAN 0, which implies the native untagged VLAN?

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Kind of a big deal

Re: Management traffic over native VLAN and double-tagging concern on MS switches

You should be able to leave it blank as @jdsilva  says.  Make sure there isn't a hidden character in there or something.

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Head in the Cloud

Re: Management traffic over native VLAN and double-tagging concern on MS switches

When you leave it as blank It will use the management VLAN under switch settings. Maybe that value is missing. And don’t worry about double tagging. If you do fill in a VLAN number and that VLAN number is the native VLAN on the uplink Port. It will send mgmt traffic untagged.

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Kind of a big deal

Re: Management traffic over native VLAN and double-tagging concern on MS switches

I just gave it a try out of curiosity.

 

Blank is not/no longer allowed. Even if you have setup the management VLAN under switch settings. I made sure no blank characters were in there.

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Head in the Cloud

Re: Management traffic over native VLAN and double-tagging concern on MS switches

Good to know.
Btw this behavior is different from AP's.  There having no VLAN in the box is the norm since you usually leave the AP mgmt untagged on the switchport.

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