11-11
Optimizing Port Usage Through Traffic Control and Port Trunking
Port Trunking
Ports: Traffic Control
and Trunking
Port Connections and Configuration: All port trunk links must be point-
to-point connections between the Switch 4108GL and another switch, router,
server, or workstation configured for port trunking. No intervening, non-
trunking devices are allowed. It is important to note that ports on both ends
of a port trunk group must have the same mode (speed and duplex) and flow
control settings.
Note Link Connections. The switch does not support port trunking through an
intermediate, non-trunking device such as a hub, or using more than one media
type in a port trunk group. Similarly, all links in the same trunk group must
have the same speed, duplex, and flow control.
Port Security Restriction. Port security does not operate on a trunk group.
If you configure port security on one or more ports that are later added to a
trunk group, the switch will reset the port security parameters for those ports
to the factory-default configuration.
Caution To avoid broadcast storms or loops in your network while configuring a
trunk, first disable or disconnect all ports you want to add to or rem ove from
the trunk. After you finish configuring the trunk, enable or re-connect the
ports.
Switch 4108GL Port Trunk Features and Operation
The Switch 4108GL offers these options for port trunking:
■LACP (IEEE 802.3ad—page 11-25)
■Trunk (non-protocol—page 11-28)
■FEC (Fast EtherChannel®—page 11-29)
The switch supports six trunk groups of up to four ports each. ( Using the Link
Aggregation Control Protocol—LACP—option, you can include standby
trunked ports in addition to the maximum of four actively trunking ports.)
LACP Note LACP op eration requires full-duplex (FDx) links. For most installations, HP
recommends that you leave the port Mode setti ngs at Auto (the default). LACP
also operates with Auto-10, Auto-100, and Auto-1000 (if negotiation selects FDx);
10FDx, 100FDx, and 1000FDx settings.
Fault Tolerance: If a link in a port trunk fails, the switch redistributes
traffic originally destined for that link to the remaining links in the trunk. The
trunk remains operable as long as there is at least one link in operation. If a