UDP Issues

Alright, well as of yesterday my dedicated server decided to crash, which is very normal every now and then, but what I didn’t expect was for it to not go back up, so I logged into RDP to see what was going down, and it seems the server startup was in abit of a loop. After abit of investigation it seemed my watchdog (Serverchecker) when going to ping the server to see if it was up, was returning false thus causing the loop.

So I had a look at the config and everything was fine but it still wouldnt go up, then I changed the port to 27016 and bingo, works first try. So I did abit more investigating and it seems nothing can connect on UDP Port 27015 on one of my IP addresses, but on any of the other 4 it works fine. I asked my datacenter about the issue, but they had no idea what-so ever to what was causing the issue as I disabled my firewalls and whatnot.


My server crashed and now it wont connect on port 27015, nothing else is using the port, have tried rebooting the dedi, have tried to run fresh installs of other games and no luck.

I would appreciate any help at all.

Your ISP may be blocking port 27015. Try calling them.

“Datacenter” sounds like a local tech support thing, if that’s your ISP, never mind then.

i highly think that the crash caused it maybe the ISP blocked that port And the crash was caused by the blocking of that port

But it shouldn’t matter if your server checking with the LAN ip

Open port 27015 in firewall. Client use UDP for the source engine. Most clients use 27005 for their client port. And most server use 27015 for there server port. Look if the packets are being denied with wire shark.

Yes but realize it happened all of a sudden. The only way the firewall would get changed is by hacking or him changing it

Yeah but listen if it’s a dedicated box the hosting company would no just block a port. So either he turned on the firewall or some how his magical host decide to block 27015 on ONE IP.

a datacenter is a place that stores comps for him for like his server http://en.wikipedia.org/wiki/Data_center


true but he said he turned off the firewall + the firewall that might block it might be out of his control Some ISP’s provide a firewall


anyway my friend said try running NetStat to see if anything else is using that port could be viral or just another process


Thanks for the help guys, my datacenter ended up finding the issue and corrected it for me.