Space Engineers Server is not Responding

[RyuKyu567]

-Network Routing-
I have a very unique problem here which I believe has been narrowed down, however I could use all the help I can get. I am currently in the process of creating a dedicated server of Space Engineers and it runs perfectly on the local network. The catch is, I can not figure out why external users are unable to connect. That in a nut shell is the issue. Now for the details.....

The reason for this being a unique issue is I am not using a standard router for my network, instead I am using a DHCP server which has RRAS enabled to be utilized as a NAT router on a Windows Server 2008 R2 platform. All firewall ports have been forwarded via port proxy to the correct destination and are listening on the correct address, I have tested it out even with the firewall off just for the heck of it and still no connections can be made.

I have spent countless hours on researching this, but all answers seem to be based on a standard home network. The list below are things I have tried (or at least can remember off the top of my head due to lack of sleep) so if anyone has any ideas or thoughts of what could be blocking or incorrectly routing the signal I would be ever so grateful!

1: Ensured ports for Steam and SE were correctly added to Windows Firewall on SE Server and DHCP Server

2: Forwarded correct ports for Steam and SE

3: Turned off Firewalls on SE server and DHCP server

4: Port checked all ports involved with both servers to ensure they are open from ISP

5: Verified that hardware is to spec to run application (just in case you are wondering)

6: Attempted to utilize different port on SE server to ensure that port was the issue

7: Took SE Server to friends house across the street to verify that it is indeed an internal networking issue and not machine/application issue

8: Verified that NAT/RRAS was configured to access internet on all other machines (vague I know, but all machines in the house are able to access internet and host other games without issue through the DHCP Server)

There are probably others but I can't recall them all. Thanks in advance, if you can think of anything it would be amazing...

 

[bill001g]

You really only have 2 things that you have to verify. 1. That the data really gets to the server, 2. That the server actually responds to the data.

To a point it is lucky you are not running a dumb router...then again it may be complexity causing the problem. Load wireshark on every device you can hopefully your server that is doing the routing function and the actual end server.

You should now be able to actually see the data. Try to keep as little traffic as possible so it does not get buried, there are capture filters in wireshark but its easier not to have to learn too much.

What you should see are SYN packets coming to the ports you want to use. You should see your server convert the ip and send them out and your other server should see them coming in with this new ip. If things were working you should see a syn ack sent back though all the devices. If you see this it means you actually have a function connection and something else at the software level is causing issues.

 

[RyuKyu567]

You really only have 2 things that you have to verify. 1. That the data really gets to the server, 2. That the server actually responds to the data.

To a point it is lucky you are not running a dumb router...then again it may be complexity causing the problem. Load wireshark on every device you can hopefully your server that is doing the routing function and the actual end server.

You should now be able to actually see the data. Try to keep as little traffic as possible so it does not get buried, there are capture filters in wireshark but its easier not to have to learn too much.

What you should see are SYN packets coming to the ports you want to use. You should see your server convert the ip and send them out and your other server should see them coming in with this new ip. If things were working you should see a syn ack sent back though all the devices. If you see this it means you actually have a function connection and something else at the software level is causing issues.

Ill give that a shot, but from what I can tell so far is the data doesn't even get past the DHCP server, then again I didn't have a tool at the time to figure out where it was going. One of the bad things about getting such a vague error of "Server Not Responding". It is very possible due to the complexity of this network that it would limit some of the traffic, would explain the issue that I had with TeamSpeak3. I had to move it just so clients could connect. Unfortunately I don't have the resources on the DHCP server to run a dedicated SE server.

If you don't mind, Ill post my results using wireshark as you suggested if you would like to review it.. Since I've been banging my head against the desk reviewing this entire squabble i'm sure I missed something.

 

[bill001g]

The wireshark posts maybe messy, even with little traffic running you are going to get quite a bit of junk traffic. You can do all kinds of fancy things with wireshark but what I would do is run the capture and then stop it. Manually scroll though the file looking for syn packets in the info field. You can then click on the packet to get the port numbers to be sure this is or is not the packet you are interest in.

It would be very hard to post anything useful there generally is way to much data. If you have issue finding what you need you can try a display filer but this quickly gets messy for someone without strong knowledge of packet formats.

There is a bar just above the capture that lets you put in display filters. Type in tcp.flags.syn==1

 

[RyuKyu567]

So after briefly messing with wireshark the first test shows that at least the signal is reaching the modem and DHCP server, however the route does not complete to the destination point shown in the figure.

To give you a rough explanation on what we are looking at, the information on the left is the local interface to the entire network that has no trace routes, while the right is the public interface which all network traffic flows through to the internet. So, there is definitely something either blocking the connection or the DHCP server does not have something configured correctly to bridge the information from one interface to the other.

 

[mjslakeridge]

I am not seeing a figure below your first sentence.

Edit: I see it now.

 

[RyuKyu567]

So I figured out the issue on why the connection could not be made. After looking into all of the firewall rules and port forwarding values I stumbled on a solution on a different site. By using this cmd I was able to successfully have user connect.

netsh routing ip nat add portmapping external udp 0.0.0.0 27016 10.7.5.136 27016.

This allowed the connection perfectly. Thanks for your help everyone!