Default Etherchannel Configuration; Hardware Support For Etherchannel; Etherchannel Configuration Guidelines And Restrictions - Cisco WS-C4003 - Catalyst 4000 Chassis Switch Software Configuration Manual

Default EtherChannel Configuration

Default EtherChannel Configuration
Table 6-2
Table 6-2
Feature
Fast EtherChannel
Gigabit EtherChannel
Frame-distribution method

Hardware Support for EtherChannel

EtherChannel support is hardware-dependent. In general, you can use the show port capabilities
command to determine whether your hardware supports EtherChannel, and to confirm which ports you
can bundle into a single EtherChannel.
An EtherChannel bundle can consist of any two to eight ports. Ports in an EtherChannel bundle do not
have to be continuous, and they do not have to be on the same module.
Due to the port ID handling by the spanning tree feature, the maximum supported number of channels
is 126 for a 6-slot chassis.

EtherChannel Configuration Guidelines and Restrictions

If improperly configured, some EtherChannel ports are disabled automatically to avoid network loops
and other problems. Use the following guidelines to avoid configuration problems:
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Software Configuration Guide—Catalyst 4000 Family, Catalyst 2948G, Catalyst 2980G, Releases 6.3 and 6.4
6-4
shows the Fast EtherChannel and Gigabit EtherChannel default configuration.
Fast EtherChannel and Gigabit EtherChannel Default Configuration
Assign all ports in an EtherChannel to the same VLAN, or configure them as trunk ports.
If you configure the EtherChannel as a trunk, configure the same trunk mode on all the ports in the
EtherChannel, on both ends of the link. Configuring ports in an EtherChannel in different trunk
modes can have unexpected results.
Configure all ports in an EtherChannel to operate at the same speed and duplex mode (full or half
duplex).
If the EtherChannel is composed of trunk ports, you must configure the same allowed VLAN range
on all the ports. When the allowed VLAN range is not the same for all trunks in a channel, trunk
ports on which a particular VLAN is not allowed will drop the packets for that VLAN while ports
on which the VLAN is allowed will transmit the traffic. If the allowed VLAN range is not the same
on all ports in the channel, the ports do not form a channel when set to the auto or desirable mode
with the set port channel command.
Configure all ports in an EtherChannel with the same GARP VLAN Registration Protocol (GVRP),
GARP Multicast Registration Protocol (GMRP), and quality of service (QoS) parameters.
Do not configure the ports in an EtherChannel as dynamic VLAN ports. You can adversely affect
switch performance.
Make sure port security is disabled on channeled ports. If you enable port security on a channeled
port, the port shuts down when it receives packets with source addresses that do not match the secure
address of the port.
Chapter 6 Configuring Fast EtherChannel and Gigabit EtherChannel
Default Value
auto silent mode on all Fast Ethernet ports
auto silent mode on all Fast Ethernet ports
Source and destination MAC
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