Cisco Nexus 5000 Series Switch Fabric Manager Software Configuration Guide, NX-OS 4.0 (OL-16598-01, June 2008)

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14-15
Nexus 5000 Series Switch Fabric Manager Software Configuration Guide
OL-16598-01
Chapter 14 Configuring SAN Port Channels
Port Channel Protocol
Step 2 Click the Channels tab and find the switch and SAN port channel that you want to edit.
Step 3 Remove the interface or list of interfaces that you want deleted in the Members the Admin column.
Step 4 Click the Apply Changes icon to save any modifications.
Port Channel Protocol
The switch software provides robust error detection and synchronization capabilities. You can manually
configure channel groups, or they can be automatically created. In both cases, the channel groups have
the same capability and configurational parameters. Any change in configuration applied to the
associated port channel interface is propagated to all members of the channel group.
Cisco SAN switches support a protocol to exchange port channel configurations, which simplifies port
channel management with incompatible ISLs. An additional autocreation mode enables ISLs with
compatible parameters to automatically form channel groups without manual intervention.
The port channel protocol is enabled by default.
The port channel protocol expands the port channel functional model in Cisco SAN switches. It uses the
exchange peer parameters (EPP) services to communicate across peer ports in an ISL. Each switch uses
the information received from the peer ports along with its local configuration and operational values to
decide if it should be part of a SAN port channel. The protocol ensures that a set of ports are eligible to
be part of the same SAN port channel. They are only eligible to be part of the same port channel if all
the ports have a compatible partner.
The port channel protocol uses two subprotocols:
• Bringup protocol—Automatically detects misconfigurations so you can correct them. This protocol
synchronizes the SAN port channel at both ends so that all frames for a given flow (as identified by
the source FC ID, destination FC ID and OX_ID) are carried over the same physical link in both
directions. This helps make applications such as write acceleration work for SAN port channels over
FCIP links.
• Autocreation protocol—Automatically aggregates compatible ports into a SAN port channel.
This section describes how to configure the port channel protocol and includes the following sections:
• About Channel Group Creation, page 14-15
• Autocreation Guidelines, page 14-17
• Enabling and Configuring Autocreation, page 14-17
• About Manually Configured Channel Groups, page 14-18
• Converting to Manually Configured Channel Groups, page 14-18
About Channel Group Creation
If channel group autocreation is enabled, ISLs can be configured automatically into channel groups
without manual intervention. Figure 14-14 shows an example of channel group autocreation.
The first ISL comes up as an individual link. In the example shown in Figure 14-14, this is link A1-B1.
When the next link comes up (A2-B2 in the example), the port channel protocol determines if this link
is compatible with link A1-B1 and automatically creates channel groups 10 and 20 in the respective