Port forwarding

[:cat_bot_creep:]

Hello.

I have no experience with web programming, but would want to set up a server on my PC just to play with a few people. However, I have a problem with port forwarding. All useful info about port forwarding for tf2 amounts to "open service port 27015 for UDP and TCP". However, the port forwarding menu on my router's firmware requieres me to put in service ports, as well as an IP and another port. However, while it's quite easy to guess that the IP is my PC's local one, I do not know what the heck am I supposed to put into the port field after the IP. I tried putting "27015" into the second field but it didn't work. So well, I'm asking what should I put in the 2nd IP field.

My router is D-link DWR-921.

INB4 I TRIED GOOGLE.

[Veni vidi vici]

its port range not a single port on that d-link haven't looked at steams at what port range steam uses but try 27015-27010

[OLDMAN🎅]

Ports 27000 to 27040 are typically used by some online games.

Steam (Valve gaming platform) uses these ports:
27000-27015 udp (Steam client game client traffic)
27015-27030 tcp/udp (typically matchmaking and HLTV, also used to download Steam content)
27031 udp, 27036 tcp/udp, and 27037 tcp (incoming for in-home streaming)
3478 udp, 4379 udp, 4380 udp (outbound - Steamworks P2P networking and voice chat)
4380 udp (Steam client)

Games:
Half-Life and its mods, such as Counter-Strike.
Empire: Total War (The Creative Assembly)
Left 4 Dead (Valve Corporation)
Team Fortress 2 (Valve Corporation)
https://www.speedguide.net/port.php?port=27015

[Ashref]

I have the same problem expect my IP doesn't have a default gate so i can't access my router. F