Often while configuring or troubleshooting network equipment you may require your computer to have an IP address in more than one subnet. This is how to do that using Windows 10.
1. Right click on the network status icon in the system tray then click Open Network & Internet settings.
2. Under Change your network settings click Change adapter options.
3. Right click the network adapter that's connected to the ethernet cable going to the AP's PoE source and click Properties.
4. Double click the Internet Protocol Version 4 (TCP/IPv4) item.
Set the IP address to be in your primary range, in this case 192.168.1.99 with a suitable subnet in this example we use the default of 255.255.255.0, enter the gateway and DNS settings if you require internet access on this interface otherwise leave the gateway and DNS settings empty then click Advanced...
Add one or more of the new IP addresses and subnets that you wish your computer to belong to, in this example we've used 172.17.2.99 with a subnet of 255.255.255.0 then OK or Close each of the properties windows.
5. Confirm that the IP address settings have applied by running ipconfig at the command prompt.
Your computer should now have an IP address in both subnets ready to configure and test the equipment on the same physical network on those other subnets.
Cleaning up after yourself
When you've completed testing or configuration, if you have no need to still have multiple IP addresses on your network interface be sure to set your IP address back to its usual fixed IP address or DHCP. This is done by following the same steps above but at step 4 remove the additional IP addresses and enter the correct static IP address, subnet, gateway and DNS or simply select to Obtain an IP address automatically and Obtain DNS server address automatically then click OK.