Need to hook a 3550-12G and 3560g together over 3 links

[william.hostetler]

The 3550-12g is my core switch and I have 3 fibers going to my server switch which is the 3560g. Do I etherchannel both sides and if I used the command line do I set them to "desirable"? I have read the literature but wading through that can be overwhelming.

thanks

Gary

[Jon Marshall]

Gary

If you are connecting them with a L2 trunk or L2 access link then yes i would recommend using etherchannel to do this as the etherchannel is then seen as just one link by STP.

Cisco recommendation is to set both ends to desirable.

Cisco also recommend to use the "spanning-tree etherchannel guard       misconfig"  command in global config mode to prevent a misconfigured etherchannel creating an STP loop.

Jon

[william.hostetler]

Jon

Thanks, I'm not a layer 2, layer 3 expert but this is just a standard plain vanilla setup in a school with no vlans etc. I will have to look up the spanning port.

Gary

[william.hostetler]

While we're at it what is the difference between Lacp and Pgap? Which one should I be using?

thanks

gary

[Jon Marshall]

PaGP is Cisco proprietary and LACP is not. Personally if you are creating an etherchannel between 2 cisco switches i would use PaGP.

Jon