Citrix XenServer host in a pool showing "No interface present"

If a host in your pool is showing "No interface present", you can perform the following steps

1. Check if the host is in emergency mode

xe host-is-in-emergency-mode 

2. If the output is "True" then change it to "False" by running

xe pool-emergency-transition-to-master

3. Ensure host is no longer in emergency mode

4. Restart toolstack

xe-toolstack-restart