Solved: Can the same native vlan be used ??

AndyGB5150 · ‎02-02-2011

Each connection is trunked.

Native vlan is 2.

Each switch has 2 ports dedicated for etherchannel.

Also negatioation is setup for non.

The top two switches on either side will be trunking 5 vlans.

The below two switches will only be trunking etc.. 1 vlan

Could the above be used.

If not would this couse any problems.

Latchum Naidu · ‎02-02-2011

Hi,

Firstly, a native VLAN is nothing else than a default VLAN given that any port in a (CISCO) switch has to assigned to one VLAN.
And By default all ports (access links) belong to VLAN 1 or native VLAN.

VLAN 1 is also used for management purposes (assigning an IP to the SW) when you need to configure your device remotly.

With regard to trunking, you need to use it to carry traffic for more than one VLAN over one physical link. This is where IEEE 802.1Q comes into play (switch to switch / switch to router).

To sum up:

VLAN 1 = Native VLAN
VLAN 1 is usually used for management purposes, however you can chose another VLAN.

A trunk link carries mutli VLAN traffic. Depending on the vendor a trunk link is either automatically configured or you will need manually to configure both ends as trunk ports as well as the protocol used (ISL, 802.1Q, etc)

Hope this cleare you...

Regards,
Naidu.

View solution in original post

Shashank Singh · ‎02-02-2011

Hi,

Everything looks fine but I just had a few remarks. Having vlan 2 as native vlan is not a problem but please be informed that on an 802.1Q trunk, all VLAN packets except the native VLAN are tagged. You must configure the native VLAN in the same way on each side of the trunk. By default the native vlan is 1 so make sure you change it across all the switches in the network, to avoid native vlan mismatch.

Make sure you have exactly the same config on all interfaces on both sides of the etherchannel. It should not be like on one end, 5 vlans are allowed on the trunk and on the other end just one vlan is allowed.

Cheers,

Shashank

P.S. Please rate the helpful post.

View solution in original post

Latchum Naidu · ‎02-02-2011

Hi,

Firstly, a native VLAN is nothing else than a default VLAN given that any port in a (CISCO) switch has to assigned to one VLAN.
And By default all ports (access links) belong to VLAN 1 or native VLAN.

VLAN 1 is also used for management purposes (assigning an IP to the SW) when you need to configure your device remotly.

With regard to trunking, you need to use it to carry traffic for more than one VLAN over one physical link. This is where IEEE 802.1Q comes into play (switch to switch / switch to router).

To sum up:

VLAN 1 = Native VLAN
VLAN 1 is usually used for management purposes, however you can chose another VLAN.

A trunk link carries mutli VLAN traffic. Depending on the vendor a trunk link is either automatically configured or you will need manually to configure both ends as trunk ports as well as the protocol used (ISL, 802.1Q, etc)

Hope this cleare you...

Regards,
Naidu.

AndyGB5150 · ‎02-02-2011

Thanks I thought that every thing would be okay.

Just needed a fresh pair of eyes.

Thanks again

Best regards

Shashank Singh · ‎02-02-2011

Hi,

Everything looks fine but I just had a few remarks. Having vlan 2 as native vlan is not a problem but please be informed that on an 802.1Q trunk, all VLAN packets except the native VLAN are tagged. You must configure the native VLAN in the same way on each side of the trunk. By default the native vlan is 1 so make sure you change it across all the switches in the network, to avoid native vlan mismatch.

Make sure you have exactly the same config on all interfaces on both sides of the etherchannel. It should not be like on one end, 5 vlans are allowed on the trunk and on the other end just one vlan is allowed.

Cheers,

Shashank

P.S. Please rate the helpful post.

AndyGB5150 · ‎02-02-2011

Thanks for the reply.

I thought that everything would be okay.

Just need another fresh pair of eyes.

Thanks again

best regards