S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
16-9
Cisco MDS 9000 Family CLI Configuration Guide
OL-16184-01, Cisco MDS SAN-OS Release 3.x
Chapter 16 Configuring PortChannels
PortChannel Configuration
•
ON (default)—The member ports only operate as part of a PortChannel or remain inactive. In this
mode, the PortChannel protocol is not initiated. However, if a PortChannel protocol frame is
received from a peer port, the software indicates its nonnegotiable status. This mode is backward
compatible with the existing implementation of PortChannels in releases prior to Release 2.0(1b),
where the channel group mode is implicitly assumed to be ON. In Cisco MDS SAN-OS Releases
1.3 and earlier, the only available PortChannel mode was the ON mode. PortChannels configured in
the ON mode require you to explicitly enable and disable the PortChannel member ports at either
end if you add or remove ports from the PortChannel configuration. You must physically verify that
the local and remote ports are connected to each other.
•
ACTIVE—The member ports initiate PortChannel protocol negotiation with the peer port(s)
regardless of the channel group mode of the peer port. If the peer port, while configured in a channel
group, does not support the PortChannel protocol, or responds with a nonnegotiable status, it will
default to the ON mode behavior. The ACTIVE PortChannel mode allows automatic recovery
without explicitly enabling and disabling the PortChannel member ports at either end.
Table 16-1
compares ON and ACTIVE modes.
To configure active mode, follow these steps:
Table 16-1
Channel Group Configuration Differences
ON Mode
ACTIVE Mode
No protocol is exchanged.
A PortChannel protocol negotiation is performed
with the peer ports.
Moves interfaces to the suspended state if its
operational values are incompatible with the
PortChannel.
Moves interfaces to the isolated state if its
operational values are incompatible with the
PortChannel.
When you add or modify a PortChannel member
port configuration, you must explicitly disable
(shut) and enable (no shut) the PortChannel
member ports at either end.
When you add or modify a PortChannel interface,
the PortChannel automatically recovers.
Port initialization is not synchronized.
There is synchronized startup of all ports in a
channel across peer switches.
All misconfigurations are not detected as no
protocol is exchanged.
Consistently detect misconfigurations using a
PortChannel protocol.
Transitions misconfigured ports to the suspended
state. You must explicitly disable (shut) and
enable (no shut) the member ports at either end.
Transitions misconfigured ports to the isolated
state to correct the misconfiguration. Once you
correct the misconfiguration, the protocol ensures
automatic recovery.
This is the default mode.
You must explicitly configure this mode.
Command
Purpose
Step 1
switch#
config t
switch(config)#
Enters configuration mode.
Step 2
switch(config)#
interface port-channel 1
switch(config-if)#
Configures the specified PortChannel (1) using the
default ON mode.
Step 3
switch(config-if)#
channel mode active
Configures the ACTIVE mode.
switch(config-if)#
no
channel mode active
Reverts to the default ON mode.
