As one of our final validation points in an ongoing project has been enabling ESX to use a LAG on both the Management and VM Networks.  The last time we did this we were unable to get it to work, and it turns out the solution was actually very simple.  Basically the core of the issue was that we were attempting to use Dynamic LACP which ESX does not support, instead you are to use Static LACP.

Create New LAG

text 
(switch01)# configure
(switch01) (Config)# port-channel esxhost00-vmnet
(switch01) (Config)# exit

Show New LAG

text 
(switch01) #show port-channel

Logical Interface Group Id Port-Channel Name Link State Mbr Ports Active Ports
----------------- -------- ----------------- ---------- --------- ------------
0/1/11            11       esxhost00-vmnet   Down      

The above command gives us the Logical Interface, which we will need.  But if we look at it with a different command we can see the problem.

text 
(switch01) #show port-channel all

Port-                  Link
Log.       Channel            Adm. Trap  STP           Mbr      Port    Port
Intf        Name        Link  Mode Mode  Mode   Type   Ports    Speed   Active
------ --------------- ------ ---- ---- ------ ------- ------ --------- ------
lag 11 esxhost00-vmnet Up     En.  En.  En.    Dynamic

The problem here is that by default we create LAGs in dynamic mode.  ESX requires static mode.

Set the LACP Mode as Static

text 
(switch01)# configure
(switch01) (Config)#interface 0/1/11
(switch01) (Interface 0/1/11)#port-channel static
(switch01) (Interface 0/1/11)#exit

Down the Switchport for the Standby Vmnic

text 
(switch01)# configure
(switch01) (Config)#interface 2/0/2
(switch01) (Interface 2/0/2)#shutdown
(switch01) (Interface 2/0/2)#exit

Review Existing ESX Portgroup Configuration

bash 
esxcli network vswitch standard portgroup policy failover get --portgroup-name="VM Network"
Load Balancing: srcport
Network Failure Detection: link
Notify Switches: true
Failback: true
Active Adapters: vmnic4
Standby Adapters: vmnic6
Unused Adapters:
Override Vswitch Load Balancing: false
Override Vswitch Network Failure Detection: false
Override Vswitch Notify Switches: false
Override Vswitch Failback: false
Override Vswitch Uplinks: true
esxcli network vswitch standard portgroup policy failover get --portgroup-name="Management Network"
Load Balancing: srcport
Network Failure Detection: link
Notify Switches: true
Failback: true
Active Adapters: vmnic4
Standby Adapters: vmnic6
Unused Adapters:
Override Vswitch Load Balancing: false
Override Vswitch Network Failure Detection: false
Override Vswitch Notify Switches: false
Override Vswitch Failback: false
Override Vswitch Uplinks: true

Change Existing ESX Portgroup Configuration

bash 
esxcli network vswitch standard portgroup policy failover set --portgroup-name="VM Network" --load-balancing=iphash --failure-detection=link --notify-switches true --failback false --active-uplinks=vmnic4,vmnic6
esxcli network vswitch standard portgroup policy failover set --portgroup-name="Management Network" --load-balancing=iphash --failure-detection=link --notify-switches true --failback false --active-uplinks=vmnic4,vmnic6

Review New ESX Portgroup Configuration

bash 
esxcli network vswitch standard portgroup policy failover get --portgroup-name="VM Network"
Load Balancing: iphash
Network Failure Detection: link
Notify Switches: true
Failback: false
Active Adapters: vmnic4, vmnic6
Standby Adapters:
Unused Adapters:
Override Vswitch Load Balancing: true
Override Vswitch Network Failure Detection: true
Override Vswitch Notify Switches: true
Override Vswitch Failback: true
Override Vswitch Uplinks: true
esxcli network vswitch standard portgroup policy failover get --portgroup-name="Management Network"
Load Balancing: iphash
Network Failure Detection: link
Notify Switches: true
Failback: false
Active Adapters: vmnic4, vmnic6
Standby Adapters:
Unused Adapters:
Override Vswitch Load Balancing: true
Override Vswitch Network Failure Detection: true
Override Vswitch Notify Switches: true
Override Vswitch Failback: true
Override Vswitch Uplinks: true

Add Both Switchports to the LAG

text 
(switch01)# configure
(switch01) (Config)#interface 2/0/3
(switch01) (Interface 2/0/3)#addport 0/1/11
(switch01) (Interface 2/0/3)#exit
(switch01) (Config)#interface 2/0/2
(switch01) (Interface 2/0/2)#addport 0/1/11
(switch01) (Interface 2/0/2)#exit
(switch01) (Config)#exit

Review LAG Configuration

text 
(switch01) #show port-channel all

Port-                  Link
Log.       Channel            Adm. Trap  STP           Mbr      Port    Port
Intf        Name        Link  Mode Mode  Mode   Type   Ports    Speed   Active
------ --------------- ------ ---- ---- ------ ------- ------ --------- ------
lag 11 esxhost00-vmnet Up     En.  En.  En.    Static  2/0/3 Auto      True
2/0/2 Auto      False

Verify ESX Connectivity

So now that we have a LAG configured and operational albeit only on one port, the traffic will either work or not.  So if you have connectivity then you should be able to safely enable the disabled port (in my case 2/0/2) and not have any problems with your traffic.  Now if you do have problems with connectivity, then you probably have a problem with something like VLANs not being configured correctly on the LAG, we ran into that when we put this into production.

Up the Switchport for the Standby Vmnic

text 
(switch01) #configure
(switch01) (Config)#interface 2/0/2
(switch01) (Interface 2/0/2)#no shutdown
(switch01) (Interface 2/0/2)#exit
(switch01) (Config)#exit

Review Final LAG Configuration

text 
(switch01) #show port-channel all

Port-                  Link
Log.       Channel            Adm. Trap  STP           Mbr      Port    Port
Intf        Name        Link  Mode Mode  Mode   Type   Ports    Speed   Active
------ --------------- ------ ---- ---- ------ ------- ------ --------- ------
lag 11 vdihost00-vmnet Up     En.  En.  En.    Static  2/0/3 Auto      True
2/0/2 Auto      True  

Now notice here that we are showing the LAGs interface up with both ports Active, so assuming that you still have basic connectivity to each of your vswitches then you should be good to go.