Autocreation Guidelines - Cisco Nexus 5500 Series NX-OS Configuration Manual

SAN Port Channel Protocol
User-Configured Channel Group
You can remove any channel group and add members
to a channel group.

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:
• 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.
• An autocreated SAN port channel is not persistent through a reboot. An autocreated SAN port channel
can be manually configured to appear the same as a persistent SAN port channel. Once the SAN port
channel is made persistent, the autocreation feature is disabled in all member ports.
• You can enable or disable the autocreation feature on a per-port basis or for all ports in the switch. When
this configuration is enabled, the channel group mode is assumed to be active. The default for this task
is disabled.
• If autocreation of channel groups is enabled for an interface, you must first disable autocreation before
downgrading to earlier software versions or before configuring the interface in a manually configured
channel group.
When enabling autocreation in any Cisco Nexus device, we recommend that you retain at least one
Tip
interconnected port between the switches without any autocreation configuration. If all ports between two
switches are configured with the autocreation feature at the same time, a possible traffic disruption may
occur between these two switches as ports are automatically disabled and reenabled when they are added
to an autocreated SAN port channel.
Cisco Nexus 5500 Series NX-OS SAN Switching Configuration Guide, Release 7.x
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◦ 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.
Configuring SAN Port Channels
Autocreated Channel Group
You cannot remove a channel group. You cannot add
members to the channel group or remove members.
The channel group is removed when no member ports
exist.
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