This document describes how to configure an upstream port channel on Cisco UCS Servers.
Cisco recommends that you have knowledge of port channels before you attempt this configuration.
The information in this document is based on Cisco Unified Computing Systems (UCS).
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
UCS port channel configuration is statically set to Link Aggregation Control Protocol (LACP) mode active. This configuration cannot be modified; therefore, all upstream port-channel configurations must adhere to LACP mode active as well. Alternatively, you can configure the upstream switchports for LACP mode passive.
Here is a sample of the UCS interface configuration that cannot be modified:
UCS1-B(nxos)# show run interface eth1/19
!Command: show running-config interface Ethernet1/19 !Time: Fri Oct 12 20:25:59 2012
You can run the show interface command on the port channel in order to show the port-channel members:
UCS1-B(nxos)# show interface po100 port-channel100 is up Hardware: Port-Channel, address: 000d.eccd.665a (bia 000d.eccd.665a) Description: U: Uplink MTU 1500 bytes, BW 20000000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA Port mode is trunk full-duplex, 10 Gb/s Beacon is turned off Input flow-control is off, output flow-control is off Switchport monitor is off EtherType is 0x8100 Members in this channel: Eth1/19, Eth1/20
The upstream port channel must be LACP to match the UCS configuration. Other configurations can be present, but (at a minimum) you should see this configuration:
5k# show run int eth1/3
!Command: show running-config interface Ethernet1/3 !Time: Sat Oct 13 00:30:51 2012
interface Ethernet1/3 switchport mode trunk spanning-tree port type edge trunk channel-group 100 mode active
Notice spanning-tree port type edge trunk on NXOS devices. This configuration ensures that, if a link flaps, the port immediately comes back up. In a failure situation, it is important that the upstream switch ports do not move through STP states, which prolong downtime. For more information on this command, refer to spanning-tree port type edge.
The Cisco IOS equivalent of this command is spanning-tree portfast trunk.