LACP interface priority - default value

[Marcogiraldo86]

Hi guys

I am studying CCNP-ENCOR book.

I have a doubt, which is the priority default value of interface partecipate to LACP?

In book example, it set G1/0/2 with command "lacp port-priority 1" and G1/0/2 become active

If i look for documentation, default value should be 1 and range should be (1 to 65535)

In my opinion it should change G1/0/1 port priority higher value than 1 to become G1/0/2 active, isn't it?

[aleabrahao]

The default value is 32768 and Lower value = higher priority.

But to be quite honest, in practice I've never seen anyone change the default priority.

[Marcogiraldo86]

From cisco documentation, default value is 1

I know that anyone change default priority, it's to find correct info.

[Htonieto · Accepted solution]

Hello @Marcogiraldo86 

From my C9500 agg switch.

Also cisco guide

Default EtherChannel Configuration

[aleabrahao]

No, the documentation shows how to set the priority, the default value is 32768.

[Giuseppe Larosa]

Hello @Marcogiraldo86 ,

other colleagues are right the default value should be 32768.

The lowest priority is preferred.

The use case is when you have one member link that should be used only when one of the primary links fail.

To make an example to create a protection link for a 2 x 10 GE links bundle we added a third 10 GE that was actually an EoMPLS running ove the MAN network.

To avoid to have this protection link used in normal conditions we configured the port lacp priority to the highest possible value on both sides.

This can combined with port channel command about minimal links that should be active to decide when the "backup" link is triggered in use.

Hope to help

Giuseppe