Does your firewall have this to allow inbound traffic at that port? Run nmap from another machine or try an online service to see if the port is being open.
Please note the IPs that you blotted out is unnecessary and actually imposes on troubleshooting if it’s not being forwarded to the right IP.
Those IPs are what’s know as private IPs. This includes the networks of 192.168.0.0/16,10.0.0.0/8,172.16.0.0/12
Everyone can use these IPs for LANs, and cannot be reached over the Internet. You have a different IP for that purpose. If you post those IPs and some wise kid thinks he can boot 192.168.0.1, they’ll end up booting themselves off. In short; it’s perfectly safe for you not to censor that out.
If the IP does not belong to those networks, do censor it.
Actually no, I didn’t add a rule for that. I thought it not necessary, but that is probably the problem. It asks wether the rule is TCP or UDP. I still haven’t found out what Garry’s Mod uses. The topics about this are very split, and I have no option to allow both. Do I just add a rule for both TCP or UDP, or is Garry’s Mod only using one of them? Also for future reference how do I find out what a game uses?
Edit: So I ended up adding all the ports for both TCP and UDP. If I use a website like canyouseeme.org, the ports still appear closed. Do I have to add a rule in firewall for outgoing traffic on these ports as well?
Inbound, 27015 on both protocols (UDP/TCP); UDP/27020 i believe is HLTV.
Outbound, you can whitelist the application, but according to the Valve wiki the outbound ports are UDP/27005, UDP/51840.
Sites like canyouseeme are going to be checking inbound, so outbound isn’t a problem still. If you are using a residential connection and within the US, you may want to look into using a different port than 27015 as its not unusual for an ISP to block this port for residential customers. Heres some troubleshooting methods you can do to isolate this issue. If you’re still lost at any of these, please post anyy images that may help us troubleshoot this issue. Images are worth a 1000 words. If you are worrried about private information, feel free to send me a PM.
What you can do is:
A) Make sure that ports are forwarded on both any routers, and the modem that you use to connect.
B) Using a separate computer on the same network, use nmap and scan for ports UDP & TCP 27015 to make sure they come back as open. Additionally, you can turn off windows firewall temporarily to make sure its not a local firewall issue, and not a port forwarding one.
If you can make contact with the port on your local network, the problem is going to be with port forwarding.
Outbound rules do not apply, NAT will pass them out. Inbound will be the focal point. Make sure that both UDP & TCP 27015 are enabled for inbound, pointing to your servers IP. You can also make a DHCP IP “sticky”, depending on your routers you can find this under LAN management, it is highly recommended to set this option if available.
If all elsle fails, your ISP may be blocking the port from connecting to the internet. For this, yyou can always set other ports to use. The link I provided earlier will help you out on doing that.