Dell OS10 Port-Channels: LACP and Static Setup

Port-channels on Dell PowerSwitch OS10 are built the same way as on most NOS platforms, but the details trip people up: the port-channel has to exist before members are added, L2 versus L3 mode is decided by switchport / no switchport, and LACP members stay inactive until both ends agree on keys and modes. This guide covers both aggregation flavours (static and dynamic LACP), the VLT case, and the verification commands that tell you whether a member is truly forwarding.

Static versus dynamic port-channels

• Static (mode on) – members are forced into the bundle with no protocol negotiation. Faster to bring up, but a miswired or half-configured peer causes silent loops or black-holed traffic because nothing verifies the far end.
• Dynamic LACP (mode active / passive) – members negotiate with LACP. At least one side must be active; both sides passive will never form a bundle. This is the recommended default for anything facing a server, a fabric or another switch.

Creating a port-channel

OS10# configure terminal
OS10(config)# interface port-channel 1
OS10(conf-if-po-1)# no shutdown
OS10(conf-if-po-1)# switchport mode trunk
OS10(conf-if-po-1)# switchport trunk allowed vlan 10,20
OS10(conf-if-po-1)# exit

OS10(config)# interface range ethernet 1/1/33-1/1/34
OS10(conf-range-eth1/1/33-1/1/34)# no switchport
OS10(conf-range-eth1/1/33-1/1/34)# channel-group 1 mode active
OS10(conf-range-eth1/1/33-1/1/34)# end
OS10# write memory

For an L3 port-channel (a routed uplink), set no switchport on the port-channel instead of a VLAN, then assign the IP address to the port-channel interface – never to the members. Members should be configured as ranges; the channel-group command also enforces that the members are consistent in speed, MTU and L2/L3 mode.

Useful knobs

interface port-channel 1
 minimum-links 2            ! keep the bundle down unless 2 members are up
 lacp individual            ! keep individual member usable when LACP fails (VLT)
 lacp fallback              ! static fallback if LACP never converges

minimum-links prevents a degraded bundle from black-holing traffic during a partial failure. lacp individual exists mainly for VLT fabrics, where you want a member to keep carrying traffic individually rather than being dropped when the LACP peer stops negotiating.

Verification commands

OS10# show interface port-channel summary
OS10# show lacp port-channel interface port-channel 1
OS10# show running-configuration interface port-channel 1
OS10# show vlt detail

Flags in show interface port-channel summary are the fastest triage tool: P means the member is up and active, I means the member is physically up but inactive (LACP not agreed), D is down and F is fallback activated. A port-channel that is up with all members flagged I is a classic symptom of a mode mismatch (active/active missing) or a VLAN/MTU mismatch between the two ends.

Troubleshooting a bundle that will not come up

• Check that both ends use the same aggregation key – on OS10 that is the port-channel ID, so port-channel 1 must peer with port-channel 1.
• Compare MTU and flow control settings; mismatched MTU silently drops large frames rather than preventing the bundle.
• Verify the member list on the peer: one member cabled to the wrong switch (or a VLT peer mismatch) shows up as I forever.
• Confirm rate limiting or QoS policies are not dropping LACPDUs; link-local protocols must not be filtered by a control-plane policy.

For the redundancy layer above the bundle, see Dell OS10 VLT troubleshooting and Dell OS10 spanning-tree configuration. Linux servers that bond into these port-channels are covered in Linux bonding 802.3ad.

原文链接：https://www.dell.com/support/kbdoc/en-us/000204226/dell-emc-networking-os10-how-to-configure-port-channels