In Catalyst 6500/6000 switches that run Catalyst OS (CatOS), EtherChannel aggregates the bandwidth of up to eight compatibly configured ports into a single logical link. With software releases 6.2(1) and earlier, the six- and nine-slot Catalyst 6500 series switches support a maximum of 128 EtherChannels. In software release 6.2(2) and later releases, the spanning tree feature handles the port ID. Therefore, the maximum number of EtherChannels with support is 126 for a six- or nine-slot chassis and 63 for a 13-slot chassis. All Ethernet ports on all modules, which include those on a standby Supervisor Engine, support EtherChannel with no requirement that ports be contiguous or on the same module. All ports in each EtherChannel must be the same speed. You can base the load-balance policy (frame distribution) on a MAC address (Layer 2 [L2]), an IP address (Layer 3 [L3]), or a port number (Layer 4 [L4]). You can activate these policies, respectively, if you issue the set port channel all distribution {ip | mac| session | ip-vlan-session} [source | destination | both] command. The session keyword is supported on the Supervisor Engine 2 and Supervisor Engine 720. The ip-vlan-session keyword is only supported on the the Supervisor Engine 720. Use this keyword in order to specify the frame distribution method, with the IP address, VLAN, and Layer 4 traffic.
