LACP port channel does not coming up on one VLT peer with physical port in "Inactive" state

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• LACP NICs are down
• Host using LAG for management cannot be managed anymore
• On Physical switch, LACP port-channel does not come on one VLT peer with physical port in "Inact" state

Example of LAG mode status on physical switch:

LAG Mode Status Uptime Ports
1 L2-HYBRID up 02:33:49 Eth 1/71/5 (Up)
2 L2-HYBRID up 02:33:43 Eth 1/71/6 (Up)
. . .
. . .
23 L2-HYBRID up 02:36:51 Eth 1/75/6 (Up)
27 L2-HYBRID down 00:00:00 Eth 1/78/4 (Inact)
32 L2-HYBRID up 02:34:31 Eth 1/74/6 (Up)
. . .
. . .
86 L2-HYBRID down 00:00:00 Eth 1/79/8 (Inact)


Example of Nic Status on ESXi host:

Name PCI Device Driver Admin Status Link Status Speed Duplex MAC Address MTU Description
------------------------------------------------------------------------------------------------------------
vmnic0 0000:17:00.0 i40en Up Up 25000 Full e4:43:4b:1d:fc:9a 1500 Intel(R) Ethernet Controller XXV710 for 25GbE backplane
vmnic1 0000:17:00.1 i40en Up Up 25000 Full e4:43:4b:1d:fc:9b 1500 Intel(R) Ethernet Controller XXV710 for 25GbE backplane
vmnic2 0000:6d:00.0 i40en Up Up 25000 Full e4:43:4b:1d:f9:22 9000 Intel(R) Ethernet Controller XXV710 for 25GbE backplane
vmnic3 0000:6d:00.1 i40en Up Up 25000 Full e4:43:4b:1d:f9:23 9000 Intel(R) Ethernet Controller XXV710 for 25GbE backplane
vmnic4 0000:85:00.0 i40en Up Up 25000 Full e4:43:4b:1d:fc:b4 9000 Intel(R) Ethernet Controller XXV710 for 25GbE backplane
vmnic5 0000:85:00.1 i40en Up Up 25000 Full e4:43:4b:1d:fc:b5 9000 Intel(R) Ethernet Controller XXV710 for 25GbE backplane
vmnic6 0000:c5:00.0 i40en Up Up 25000 Full e4:43:4b:1d:fb:2e 9000 Intel(R) Ethernet Controller XXV710 for 25GbE backplane
vmnic7 0000:c5:00.1 i40en Up Up 25000 Full e4:43:4b:1d:fb:2f 9000 Intel(R) Ethernet Controller XXV710 for 25GbE backplane


localcli network vswitch dvs vmware lacp config get
DS-165 lag1 502434942 vmnic4,vmnic5 true Active Src and dst ip, port, vlan

localcli network vswitch dvs vmware lacp stats get
DVSwitch LAG ID NIC Rx Errors Rx LACPDUs Tx Errors Tx LACPDUs
-------------------------------------------------------------------------
DS-165 502434942 vmnic4 0 875 0 847
DS-165 502434942 vmnic5 0 38 0 38

Environment

VMware ESXi 6.7.x
VMware ESXi 6.5.x
VMware vSphere ESXi 7.0.0

Cause

The LACP PDUs from ESXi host does not send actor sync flag true regardless of its partner sync flag. Hence the Lag mode is inact in physical switch.

Resolution

To work around this issue, toggle the LACPActorSystemPriority to 1 on ESXi host.
Log into ESXi shell and execute the below commands to achieve this :

1. Run this command to know the current LACPActorSystemPriority :

esxcfg-advcfg -g /Net/LACPActorSystemPriority

 2. Run this command to toggle the LACPActorSystemPriority to 1 :
esxcfg-advcfg -s 1 /Net/LACPActorSystemPriority
3. To verify the above settings are changed, execute below command & ensure the value set is reflected :
esxcfg-advcfg -g /Net/LACPActorSystemPriority
4. Reboot the ESXi host from DCUI or restart the lacp deamon after the above commands are executed.