Etherchannel

Two Negotiating Protocols

• Port Aggregation Protocol (PAGP)

  • Cisco Proprietary

  • Port Modes: Auto, Desirable, On

• Link Aggregatrion Control Protocol (LACP)

  • Industry standard (802.3ad)

  • Port modes: passive, active, on

Configuring EtherChannel

Layer 2 EtherChannel

int r g0/23 - 24
channel-protocol pagp
channel-group 1 mode desireable

show etherchannel 1 port

Layer 3 EtherChannel

int r g0/23 -24
no channel-group 1
no switchport
int port-channel 1
no switchport
ip address 10.1.1.1 255.255.255.0
channel-group 1 mode desireable

Best Practices

• All ports must use same speed and duplex (hard code!)

• Interfaces in a bundle are redundant

• No interfaces in bundle can be span ports

• Interfaces in a bundle must be in same VLAN / trunk

• Any changes to port-channel affects all bundled ports

• Any changes to individual ports affect only that port