I have a very simple gateway running a minimal Linux which is serving as an IP router with NAT and DHCP on the LAN, and a static IP on the WAN. The gateway router from the LAN side goes to a big switch from which about 200 users gain access (DHCP assigns them NAT addresses). Of these 200 hosts on the LAN I have one which (call it Argon) that I'd like to access at a fixed static IP address from both within the LAN and from the WAN. Let's say my NAT is 192.168.1.0/24, the LAN address on my gateway is 192.168.1.1, Boron is a host on the LAN with IP 192.168.1.2, and Carbon is a host on the WAN with the IP 22.214.171.124.
Say that I own the IP 10.10.10.10. I'd like to assign 10.10.10.10 to Argon, and be able to send and receive both TCP and UDP traffic from both Boron (at 192.168.1.2) and from Carbon (at 126.96.36.199) where both Boron and Carbon would send messages to the IP address 10.10.10.10 to reach Argon.
I don't think my router has the capability to run DNS or VPN so I'd like to avoid these routes as solutions if possible. However if the constraints I've places make the problem unsolvable I'd prefer to set up a DNS as a solution rather than VPN so if anyone has a DNS solution for this problem (that isn't dynamic DNS) I'd appreciate those solutions too.
Apologies if the question is basic, or not on point; I'm definitely a networking novice.
Thank you for your help.