CCIE Written: EtherChannel

Ether Channel

* Used to aggregate bandwidth of physical links

                - Same logic as PPP Multilink

* Consists of two parts

                - Port-channel interface

                   + Logical interface representing the link bundle

                - Members interfaces

                   + Physical links part of a link bundle

* Channel can be any type of interface

                - i.e. Layer 2 access, trunk, tunnel or layer 3 routed

EtherChannel Negotiation

* channel-group [number] mode [mode]

* Mode determines how negotiation occurs

                - On: No negotiation  and permanently enable

                - Desirable & Auto: Initiate or listen for PAgP

                - Active & Passive: Initiate or listen for LACP (802.3ad)

* PAgp vs LACP

                - Like ISL vs 802.1q

EtherChannel Mode Compatibility

* On – On

* Desirable – Desirable

* Desirable – Auto

* Active – Active

* Active – Passive

EtherChannel Load Balancing

* Load balancing between member interface based on

                - Source MAC Address

                - Destination MAC address

                - Source IP Address

                - Destination IP Address

                - Combinations of the four

* Modified with port-channel load-balance