LACP: Why should I use passive-active mode instead active-active mode?

[marioguido93]

Hello guys,

i'm studying etherchannel for my CCNP exam and would like to know in which scemario it could be useful to use an active-passive configuration.

Regards

Mario

[Rajeev Sharma]

Hey Mario,

Active-Passive would be required if you want one device (Active) to control LACP negotiation.

HTH.

Regards,
RS.

[marioguido93]

Hi Rajeev,

Thank you for the answer, but, why I should have just one device to control LACP negotiation? Why not both? What are the advantages?

Are there any scenarios where you MUST have a port channel with LACP active-passive mode? (Maybe for security reasons?)

Thank you

Regars,

Mario

[Reza Sharifi · Accepted solution]

Hi Mario,

You don't have to run active/passive. There is no issue with running LACP as active/active.  As a matter of fact, when you connect Nexus 2ks to 5ks or 7ks active/active should be configured.

In active/passive active side negotiate and the passive side minimizes transmission of LACP packets (less noise).

HTH

[paul driver]

Hello

Also setting one side to passive and the other to active   would be beneficial if your not sure if LACP is supported  on the link

res

Paul

[marioguido93]

Hi Paul,

Passive mode is just for LACP protocol, so when you use it, you have to be sure that is supported on the other side of the link.

Right?

res

M

[masoomsidd]

how to know other link is supported.

[Georg Pauwen]

Hello,

as a rule of thumb, since LACP is open standard and supported by most vendors, if the other side is not a Cisco device, LACP is supported. If both sides are Cisco devices, PAGP (Cisco proprietary) and LACP are both supported.