HP Cisco MDS 9124 Cisco MDS 9000 Family Fabric Manager Configuration Guide, Re - Page 469

Chapter 23 Configuring PortChannels PortChannel Protocol Send documentation comments to [email protected] The PortChannel protocol uses two sub-protocols: • Bringup protocol-Automatically detects misconfigurations so you can correct them. This protocol synchronizes the PortChannel 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 like write acceleration work for PortChannels over FCIP links. • Autocreation protocol-Automatically aggregates compatible ports into a PortChannel. This section describes how to configure the PortChannel protocol and includes the following sections: • About Channel Group Creation, page 23-17 • About Autocreation, page 23-18 • Enabling and Configuring Autocreation, page 23-19 • About Manually Configured Channel Groups, page 23-19 • Converting to Manually Configured Channel Groups, page 23-19 About Channel Group Creation Note Channel groups are not supported on internal ports in the Cisco Fabric Switch for HP c-Class BladeSystem and the Cisco Fabric Switch for IBM BladeSystem. Assuming link A1-B1 comes up first in Figure 23-15, that link is operational as an individual link.When the next link, say A2-B2 comes up, the PortChannel protocol identifies if this link is compatible with link A1-B1 and automatically creates channel groups 10 and 20 in the respective switches. If link A3-B3 can join the channel groups (and hence, the PortChannels), the respective ports have compatible configurations. If link A4-B4 operates as an individual link, it is because of the incompatible configuration of the two end ports with the other member ports in this channel group. Figure 23-15 Autocreating Channel Groups Channel Group 10 Channel Group 20 1 po10 po20 1 2 Cisco MDS Switch A 3 2 Cisco MDS 3 Switch B 4 4 120489 The channel group numbers are selected dynamically, and as such, the administrative configuration of the ports forming the channel group at either end are applicable to the newly created channel group. The channel group number being chosen dynamically may be different across reboots for the same set of PortChannels based on the order of ports that are initialized in the switch. Table 23-2 identifies the differences between user-configured and auto-configured channel groups. OL-16184-01, Cisco MDS SAN-OS Release 3.x Cisco MDS 9000 Family CLI Configuration Guide 23-17