[HCX] Cant enable MON on F5 VM

Products

• VMware HCX

Issue/Introduction

F5 load-balancers utilize a feature called "floating-ip". This is used by the F5 appliances in failover scenarios. 

This article will describe how to enable MON on an F5 VM's "floating-ip". 

 

When enabling MON on F5 LB vm you may see the VM status as "waiting for IP" in HCX UI under "network extension"

Environment

HCX

F5 Load Balancer

Cause

HCX relies on VMware tools to pull the IP address from the VM you are attempting to enable MON on. VMware tools can only see IPs attached to a VM network interface.

In the case of these F5 VMs this "floating-ip" is not attached to a VM interface therefore HCX cannot discover the IP. 

When enabling MON HCX expects that a VM that resides on a stretched network will have only NES-T segments attached to it.  It does not support having a combination of NSX-T segment and Distributed Port Group backed network adapters. 

 

Resolution

This issue is reported as fixed in 4.11 

Below workaround can be performed to enable MON:

1. Create a dummy VM with 2 NICs - Guest OS type does not matter as long as it has VMware tools installed.
2. One of the VM's nic's will be for mgmt. - so user can admin this vm. 
3. The second nic should have the floating IP assigned. 
   • Once floating IP is assigned to second nic - user should admin down the NIC within guest OS.
   • For Windows navigate to Device Manager, locate the specific network adapter, right-click on it and then select "Disable"
   • For Linux OS use the command sudo ip link set <interface_name> down
     • interface_name is the name of the network adapter you want to disable.
4. Edit dummy VM via vCenter and attach the network interface which is assigned floating IP to MON enabled network.
5. This will enable MON on said IP and push corresponding routes/configs to NSX edge.