Wired Intelligent Edge

Hi guys,

 

I have a network which one 3810M core switch and many 2930F access switches. I use many VLANs, and my management VLAN is VLAN 100. I don't use VLAN 1. I wonder if I can remove VLAN 1 of my switches and my trunk links (with trunks I refer to links which support many tagged VLANs and not link aggregations), or I have to leave this VLAN because it is used for some management protocols or features such as LACP or STP, just to name a few.

 

Regards,
Julián

No it isnt possible to remove the default vlan1. Simple dont use it and dont tagged or untagged it to any interfaces.

Hi,

 

So it is not possible to delete VLAN 1 on the switches because it is the default VLAN. Currently I don't use this VLAN and travels untagged on my trunk links together with many tagged VLANs. So if I remove it on my trunk links (like vlan 1 no untagged trk1) everything will be OK? Is it not used for some protocols (LACP, STP, etc.)?

 

Regards,

Julián

Greetings!

 

As long as at least one other VLAN is assigned to a port or trunk (tagged or untagged), VLAN 1 can be removed from that port/trunk without issues.  Note that, if all other VLANs are removed from a port, it will automatically be moved back to VLAN 1 (untagged) as ports cannot be 'orphaned'.

 

As it is the 'default' VLAN, VLAN 1 cannot (as already mentioned) be removed from the switch entirely.

Hi Mathew,

 

That's clear, the question then if VLAN 1 is used for some protocols such as LACP or STP. I remember that Cisco uses the native VLAN for the messages of some protocols, I don't know if this happens in Aruba as well.

 

Regards,

Julián

Hi Julian,

 

Like you mentioned above that you want to use the VLAN100 as a management VLAN and wants to remove the VLAN1. 

As VLAN 1 is the default VLAN, which means that it cannot be removed or deleted. In your case you have to assign a new VLAN to the port you want, and set it as UNTAGGED. After this, only this new VLAN will be forwarded in the port. If you set the new VLAN as tagged, you will permit the VLAN 1 to pass untagged and the new VLAN to pass tagged. After this custom settings, the new VLAN will be the PVID of the port.

Now, if you will make any other VLAN as a management VLAN then in that case you cannot access the switch with anyother VLAN and this new management will not not pass any data traffic. 

We don't have any concept of native VLAN unless or untill the ports are assigned to a particular VLAN and the VLANS are up they will pass the traffic. If there is nothing connected or no ports assigned to a VLAN if will not work for any protocol.

 

Config to create a Management VLAN:

Switch(config)# management-VLAN (VLAN ID).// just make sure OOBM is disable on the switch as both will will not work simaultaneously//

 

Regards,

Sahil Raina

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@fjulianom wrote:

Hi Mathew,

 

That's clear, the question then if VLAN 1 is used for some protocols such as LACP or STP. I remember that Cisco uses the native VLAN for the messages of some protocols, I don't know if this happens in Aruba as well.

 

Regards,

Julián

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@fjulianom wrote:

Hi Mathew,

 

That's clear, the question then if VLAN 1 is used for some protocols such as LACP or STP. I remember that Cisco uses the native VLAN for the messages of some protocols, I don't know if this happens in Aruba as well.

 

Regards,

Julián

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Hi Sahil,

 

Thanks for your explanation. Right now VLAN 100 is my management VLAN because I use this VLAN for accessing the switches by CLI, but it is not configured as management-VLAN (I have to read about this feature).

Think of a situation as mine where two switches are connected each other with a LACP link aggregation, and this link aggregation has only tagged VLANs (100, 200, 300, etc.). What VLAN the switches will use to transmit the LACP messages?

 

Regards,

Julián

Think of a situation as mine where two switches are connected each other with a LACP link aggregation, and this link aggregation has only tagged VLANs (100, 200, 300, etc.). What VLAN the switches will use to transmit the LACP messages?

Answer:

If you will check the switch configure on VLAN if that Trk group is not assigned to any other VLAN then only above mentioned VLANs will pass the traffic. The moment you put the ports in a trunk group you will no longer be able to use the ports individually, you will have to use the trunk gruop. 

Note: If you will delete the trunk group the ports which were assigned to it will get removed from the other VLANs and get assigned to the VLAN1 as per the desgin of architecture.

when you will do "show VLAN port trk (trunk group no or interface no) detail if will give you the exact VLANS assigned to a trunk group or interface.

Regards,

Sahil Raina

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@fjulianom wrote:

Hi Sahil,

 

Thanks for your explanation. Right now VLAN 100 is my management VLAN because I use this VLAN for accessing the switches by CLI, but it is not configured as management-VLAN (I have to read about this feature).

Think of a situation as mine where two switches are connected each other with a LACP link aggregation, and this link aggregation has only tagged VLANs (100, 200, 300, etc.). What VLAN the switches will use to transmit the LACP messages?

 

Regards,

Julián

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Hi Sahil,

 

That's clear. My question is what VLAN the switches will use to transmit the LACP messages? In general, what VLAN the switches will use to transmit the protocol messages? For example, for LACP there are LACPDUs, for STP there are BPDUs. What VLAN these messages will travel over?

 

Regards,

Julián 

My question is what VLAN the switches will use to transmit the LACP messages? In general, what VLAN the switches will use to transmit the protocol messages? For example, for LACP there are LACPDUs, for STP there are BPDUs. What VLAN these messages will travel over?

 

Answer:

Like i mentioned there is no concept of native VLANS, if the ports the assigned to the VLANs it will pass the traffic and protocol messages. By default all the ports assigned to VLAN 1 and they will use this VLAN to pass the traffic and messages, if you have other VLANs as well on the same port the traffic and message will pass from all the VLANS.

Basically when the traffic come out from the switch it will either have untagg or tagg frame added to it.

Now if you do want to pass any traffic or message from VLAN 1 just do (no untagg port number or the trk group no ) on VLAN 1. 

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@fjulianom wrote:

Hi Sahil,

 

That's clear. My question is what VLAN the switches will use to transmit the LACP messages? In general, what VLAN the switches will use to transmit the protocol messages? For example, for LACP there are LACPDUs, for STP there are BPDUs. What VLAN these messages will travel over?

 

Regards,

Julián 

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Regards,

Sahil Raina

 

Hi Sahil,

 

Then in a situation as mine where two switches are connected each other with a LACP link aggregation (trk), and this link aggregation has only tagged VLANs, for example 100, 200 and 300, and there is no untagged VLANs assigned to it, does VLANs 100, 200 and 300 carry data traffic and also protocol messages?

 

Regards,

Julián

Then in a situation as mine where two switches are connected each other with a LACP link aggregation (trk), and this link aggregation has only tagged VLANs, for example 100, 200 and 300, and there is no untagged VLANs assigned to it, does VLANs 100, 200 and 300 carry data traffic and also protocol messages?

 

Answer:

Yes, it will carry both data traffic and protocol messages through these VLANS

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@fjulianom wrote:

Hi Sahil,

 

Then in a situation as mine where two switches are connected each other with a LACP link aggregation (trk), and this link aggregation has only tagged VLANs, for example 100, 200 and 300, and there is no untagged VLANs assigned to it, does VLANs 100, 200 and 300 carry data traffic and also protocol messages?

 

Regards,

Julián

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IEEE protocols like LLDP, STP and LACP are always transmitted untagged over a link regardless if you only have tagged VLANs assigned on the port. And those protocols have nothing to do with VLAN 1.

Hi Holger,

 

Thanks very much for the clarification. That makes much more sense than data VLANs are used to carry these protocols.

 

Regards,

Julián