Implications of creating a new VLAN?

[xxcaligulaxx]

Is it recommended to create a new VLAN within a switched environment, involving numerous switches with redundant links, during the normal working day. When the new VLAN is created am I correct in thinking that the trunk links will go through the listening, learning , forwarding/blocking etc. During this time data will not be passed through the trunks and therfore conenctivity between the switches will be impacted for up to 45 seconds?

Would good practise be to cover this with a CM and carry out the change outwith normal working hours.

Or am I worrying about nothing and it is perfectly acceptable to create vlans anytime?

[Kevin Dorrell]

Normally if your VTP domain is working correctly, you can add a VLAN without any impact. You should add the VLAN at a VTP server switch. The switches maintain a separate Spanning Tree for each VLAN, so the only VLAN that will go through the convergence process will be the new one.

I say "normally" just as a disclaimer, in case your architecture is unusual in any way. On my network, I can add and delete VLANs with impunity.

Kevin Dorrell

Luxembourg

[xxcaligulaxx]

Thanks for the info, I hoped that would be the consensus of opinion.

Cheers

[pflunkert]

Hi ,

when you configure the vlan for the first time in your network, the affect to the other vlans depends from the spanning tree. When you have for example a Per-Vlan-Spanning Tree only the new vlan will be affected. So you can add new vlans without problems.

Regards

Peter

[xxcaligulaxx]

Thanks for the info, I hoped that would be the consensus of opinion.

Thanks.