11-14
Optimizing Port Usage Through Traffic Control and Port Trunking
Port Trunking
Ports: Traffic Control
and Trunking
Table 11-5. General Operating Rules for Port Trunks
Media: All ports on both ends of a trunk group must have the same media type and mode (speed and duplex). The switch
blocks any trunked links that do not conform to this rule. (For t he Switch 4108GL, HP recommends leaving the port Mode
setting at Auto or, in networks using Cat 3 cabling, Auto-10.)
Port Configuration: The default port configuration on the Switch 4108GL is Auto, which enables a port to sense speed
and negotiate duplex with an Auto-enabled port on another dev ice. HP recommends that you use the Auto setting for al l
ports you plan to use for trunking. Otherwi se, you must manually ensure that the mode sett ing for each port in a trunk is
compatible with the other ports in the trunk.
All of the following operate on a per-port basis, regardless of trunk mem bership:
•Enable/Disable
•Flow control (Flow Ctrl)
LACP is a full-duplex protocol. See “Trunk Group Operation Usi ng LACP” on page 11-25.
Trunk Configuration: All ports in the same trunk group must be the same trunk type (LACP, Trunk, or FEC). All LACP ports
in the same trunk group must be either all static LACP or all dyna mic LACP.
A trunk appears as a single port labeled Dyn1 (for an LACP dynamic trunk) or Trk1 (for a static trunk of any type:
LACP, Trunk, or FEC) on various menu and CLI screens. For a listing of which screens show which trunk types, see “How
the Switch Lists Trunk Data” on page 11-29.
For STP or VLAN operation, configurati on for all ports in a t runk is done at the trunk level. (You cannot separately configure
individual ports within a trunk for STP or VLAN ope ration.)
Traffic Distribution: All of the switch trunk protocols use the SA/DA (Source Address/Destination Address) metho d of
distributing traffic across the trunked links. See “Outbound Traffic Distribution Across Trunked Links” on page 11-30.
Recommended Port Mode Setting for LACP