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PortFast on EtherChannel Ports ?

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chazk1

Technical User
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Sep 3, 2001
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I am configuring 4 ports on a Catalyst 4003 as an Etherchannel to a Catalyst 2970.

Can you confirm whether Portfast has to be disabled on these 4 ports ? What would be the effect if not disabled, loops ?
 
Don't turn portfast on these ports.

Portfast tell the switch to bring up the port, before it finishes the spanning-tree process.

If a switch connection comes up before the spanning-tree process, there could be a loop in your network. Spanning-tree allows you to have physical loops (one active and the rest disabled). If you bring the connection up, before spanning-tree knows about it you'll have a loop. When a loop happens, packets will ride the network mary-go-round. :)

It's good network design to have a physical network loop, but spanning-tree keeps the network loop free. Hope this makes sense.
 
Cheers. You've confirmed what I already thought.
 
Turn on uplinkfast if anything..

BuckWeet
 
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