System information

Link Aggregation Commands
4-131
4
Link Aggregation Commands
Ports can be statically grouped into an aggregate link (i.e., trunk) to increase the
bandwidth of a network connection or to ensure fault recovery. Or you can use the
Link Aggregation Control Protocol (LACP) to automatically negotiate a trunk link
between this switch and another network device. For static trunks, the switches have
to comply with the Cisco EtherChannel standard. For dynamic trunks, the switches
have to comply with LACP. This switch supports up to 26 trunks. For example, a
trunk consisting of two 1000 Mbps ports can support an aggregate bandwidth of
4 Gbps when operating at full duplex.
Guidelines for Creating Trunks
General Guidelines –
• Finish configuring port trunks before you connect the corresponding network
cables between switches to avoid creating a loop.
• A trunk can have up to 8 ports.
• The ports at both ends of a connection must be configured as trunk ports.
• All ports in a trunk must be configured in an identical manner, including
communication mode (i.e., speed and duplex mode), VLAN assignments, and
CoS settings.
• Any of the Gigabit ports on the front panel can be trunked together, including
ports of different media types.
• All the ports in a trunk have to be treated as a whole when moved from/to,
added or deleted from a VLAN via the specified port-channel.
• STP, VLAN, and IGMP settings can only be made for the entire trunk via the
specified port-channel.
Table 4-45 Link Aggregation Commands
Command Function Mode Page
Manual Configuration Commands
interface port-channel Configures a trunk and enters interface
configuration mode for the trunk
GC 4-120
channel-group Adds a port to a trunk IC (Ethernet) 4-132
Dynamic Configuration Commands
lacp Configures LACP for the current interface IC (Ethernet) 4-133
lacp system-priority Configures a port's LACP system priority IC (Ethernet) 4-134
lacp admin-key Configures a port's administration key IC (Ethernet) 4-135
lacp admin-key Configures an port channel’s administration key IC (Port Channel) 4-135
lacp port-priority Configures a port's LACP port priority IC (Ethernet) 4-136
Trunk Status Display Commands
show interfaces status
port-channel
Shows trunk information NE, PE 4-127
show lacp Shows LACP information PE 4-137