Adding another link with etherchannel-PAGP

[Shibu1978]

Hi all,

I have a 10g trunk link between my two 4510 coreswitches.   Now the utilization on this link is shooting up to 9.5gb which is forcing us to put another 10g link  between these two switches.

We are planning to configure Etherchannel-PAGP. There should be any sort of downtime on the current link while adding another link to it.

How do i add another link with etherchannel -PAGP with out having downtime on the current link?  could you please guide me on this?

Thanks

Shibu

[Jon Marshall]

Do you already have the current link configured in a port channel or is it simply a trunk link ?

If it is not already part of an etherchannel then you will need downtime because it will take the existing link down before forming an etherchannel with the new link.

Jon

[Shibu1978]

Thanks Jon

no its not part of a etherchannel.

Its only a trunk link. so we while configuring there will be a downtime on the existing link right ?

What is the best way to configure etherchannel with existing and new link?

[Jon Marshall · Accepted solution]

Not sure what you mean by best way ?

You are going to have to schedule an outage to do this if the existing link is not part of an etherchannel already.

So just make sure ports at both ends have same settings, configure the etherchannel and it should come up fine.

Jon

[JohnTylerPearce · Accepted solution]

Shibu,

Jon is 100% correct, that since this is not already and Etherchannel, there will be downtime, but it should be minimal. Now, what you could do, is depending on your physical topology, you should connect these two switches together with a GigbitEthernet link in the meatnime, it will be blocked by spanning tree (if it's a L2 port), since the 10G link will be give priority by default. Then you could afford downtime on the 10 gig link, while you create an etherchannel, If these two links are L2, you could configure UplinkFast, so the switchover is VERY fast.

I've done this same setup before when making changes, but it all depends on if you can acutally physically do that. If not, you will have some downtime involved.

You can also, just configure all this on notepad, and copy and paste.