PAgP, LACP, and Static

There are three methods of EtherChannel configuration on Cisco switches:

• PAgP (Port Aggregation Protocol)

  • Cisco proprietary protocol.

  • Dynamically negotiates the creation/maintenance of the EtherChannel.

• LACP (Link Aggregation Control Protocol)

  • Industry-standard protocol (IEEE 802.3ad).

  • Dynamically negotiates the creation/maintenance of the EtherChannel. (like DTP does for trunks).

• Static EtherChannel

  • A protocol isn't used to determine if an EtherChannel should be formed.

  • Interfaces are statically configured to form an EtherChannel.

Up to 8 interfaces can be formed into a single EtherChannel (LACP allows up to 16, but only 8 will be active, the other 8 will be in standby mode, waiting for an active interface to fail).