Troubleshoot IP pool issues in NSX
First, let’s reference Creating IP Pools in NSX. The only configuration of an IP Pool is the Name, Gateway, Prefix Length, DNS, and Static IP Pool as shown below. The first thing to confirm, is that you have the gateway, prefix length, and IP Pool settings correct.
If everything looks good, ensure that there are enough IPs in the pool. If you look at my configuration below, you will see that my VXLAN pool has used all 4 IPs in the pool.
If you click the used link you will see what IPs are allocated.
If I tried to install another host and configure VXLAN, I would get an error about insufficient IPs in my pool. Ensure that the pool is big enough, and if it needs more IPs, you can edit the pool by clicking the penil icon and increase the pool.