Cisco Nexus 5000 Series Switch CLI Software Configuration Guide (OL-16597-01, July 2009)

Table 71: Channel Group Configuration Differences
Autocreated Channel GroupUser-Configured Channel Group
Created automatically when compatible links come
up between two compatible switches, if channel group
autocreation is enabled in all ports at both ends.
Manually configured by the user.
None of these ports are members of a user-configured
channel group.
Member ports cannot participate in autocreation of
channel groups. The autocreation feature cannot be
configured.
All ports included in the channel group participate in
the SAN port channel. No member port becomes
You can form the SAN port channel with a subset of
the ports in the channel group. Incompatible ports
isolated or suspended; instead, the member port isremain in a suspended or isolated state depending on
the On or Active mode configuration. removed from the channel group when the link is
found to be incompatible.
Any administrative configuration made to the SAN
port channel is applied to all ports in the channel
Any administrative configuration made to the SAN
port channel is applied to all ports in the channel
group, but the configurations are saved for thegroup, and you can save the configuration for the port
channel interface. member ports; no configuration is saved for the port
channel interface. You can explicitly convert this
channel group, if required.
You cannot remove a channel group. You cannot add
members to the channel group or remove members.
You can remove any channel group and add members
to a channel group.
The channel group is removed when no member ports
exist.
Autocreation Guidelines
When using the autocreation protocol, follow these guidelines:
• A port is not allowed to be configured as part of a SAN port channel when the autocreation feature is
enabled. These two configurations are mutually exclusive.
• Autocreation must be enabled in both the local and peer ports to negotiate a SAN port channel.
• Aggregation occurs in one of two ways:
◦ A port is aggregated into a compatible autocreated SAN port channel.
◦ A port is aggregated with another compatible port to form a new SAN port channel.
• Newly created SAN port channels are allocated from the maximum possible port channel number in a
decreasing order based on availability. If all port channel numbers are used up, aggregation is not allowed.
• You cannot change the membership or delete an autocreated SAN port channel.
• When you disable autocreation, all member ports are removed from the autocreated SAN port channel.
• Once the last member is removed from an autocreated SAN port channel, the channel is automatically
deleted and the number is released for reuse.
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
526 OL-16597-01
Configuring SAN Port Channels
Autocreation Guidelines