Server disappearing from list

Kaltrip

I've been seeing a lot of posts about servers not appearing, or appearing and disappearing from the server list. I've been assuming this is down to firewall issues especially when the servers are running on private / dynamic addresses and NAT is involved. Well, now it is happening to me.

I'm running the Linux version of the nwserver software on a physical server, with a static address and no VM involved. There is a Linux firewall (iptables) which allows through UDP port 5121 inbound and allows all outbound traffic. The server was appearing in the list but now it isn't. There has been no change on the firewall and obviously the IP address has remained fixed. It was originally working without having to use the publicserver option set to 1 on the command line, but I have now tested with and without that setting without making any apparent difference.

I'm now trying to understand the process by which the server registers with the master server. I'm running a packet tracer and can see any traffic that I might want to look at, but would appreciate any clues about what I should be expecting. Looking at the server binary image I can see the string "nwmaster.beamdog.net" which resolves to 52.42.27.67. I was expecting some sort of communication to that address but I'm seeing nothing. Could that be the cause of my problem, and does anyone have ideas about what to try next?

Kaltrip

Additional info in case it might be useful. When I restart the server I see attempts every 10 seconds to target two specific addresses on UDP port 5121:

19:42:02.401664 IP A.B.C.D.5121 > 66.244.193.9.5121: UDP, length 6
19:42:12.410082 IP A.B.C.D.5121 > 209.5.183.137.5121: UDP, length 6
19:43:02.438275 IP A.B.C.D.5121 > 66.244.193.9.5121: UDP, length 6
19:43:12.443264 IP A.B.C.D.5121 > 209.5.183.137.5121: UDP, length 6
19:44:02.475698 IP A.B.C.D.5121 > 66.244.193.9.5121: UDP, length 6
19:44:12.483277 IP A.B.C.D.5121 > 209.5.183.137.5121: UDP, length 6

Does anyone know what these addresses are? I'm not seeing any responses to these requests. I should also probably mention that I can get to my server and play over the public internet if I use the entry in the history list put there when I was able to see the server in the main list.

Kaltrip

Further information. One of the mystery IP addresses seems to be part of Bioware's address space. If I trace to 66.244.193.9, the I see the trace bouncing off Bioware's network edge without going anywhere:

$ mtr 66.244.193.9 Packets Pings Host Loss% Snt Last Avg Best Wrst StDev 14. ra2ar-tge2-1.ed.shawcable.net 0.0% 34 187.6 191.2 187.3 312.2 21.4 15. gateway.bioware.com 0.0% 34 191.5 191.5 191.4 191.9 0.0 16. ra1ar-ge3-2-21.ed.bigpipeinc.com 0.0% 34 191.7 198.1 191.6 351.6 28.9 17. gateway.bioware.com 0.0% 34 192.9 192.7 192.5 193.8 0.2 18. ra1ar-ge3-2-21.ed.bigpipeinc.com 0.0% 34 192.9 202.2 192.6 399.4 38.3

I'm guessing this might be linked to the now defunct Bioware authentication service? In which case why would the EE server still be making requests to this service? More importantly why does it not appear to be attempting communication with nwmaster.beamdog.net?

niv

Hello,

nwmaster.beamdog.net is the only masterserver address right now. The IPs you are seeing are allocated to consumer endpoint ISPs, Shaw and Rogers. I suspect you're seeing player-sourced traffic reponses/queries/attempts; as these go over 5121 too (everything does, in fact).

Kaltrip

Well, one of the two IP addresses (66.244.193.9) belongs to Bioware and this traffic corresponds to outbound UDP packets sent *from* a freshly started server. I'm not seeing any inbound traffic from those addresses and only see outbound traffic when I start the nwserver software. That is why I think it is the server software which is making these requests.

As a more general question, does anyone here know the mechanism of how a server registers with the server hosting the master list? Is it an outbound UDP traffic sent to port 5121 on the remote server. Does anyone know the IP address of the server that hosts the master list? What I'm thinking is that I should be seeing outbound traffic to nwmaster.beamdog.net (52.42.27.67). Instead I'm seeing absolutely no traffic to or from this server and think this may be the reason my server appears to be no longer registering with the master list server.

Kaltrip

OK, so I figured that I could find out where the server would try to communicate by watching for any DNS name resolution requests going out from my server. What I see is pretty much what I expected; every minute it attempts to resolve nwmaster.beamdog.net.
# tcpdump -i em1 -s 256 -n -p udp and port 53 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on em1, link-type EN10MB (Ethernet), capture size 256 bytes 14:14:20.143678 IP A.B.C.D.51801 > 8.8.8.8.53: 58839+ A? nwmaster.beamdog.net. (38) 14:14:20.196411 IP 8.8.8.8.53 > A.B.C.D.51801: 58839 2/0/0 CNAME ec2-52-42-27-67.us-west-2.compute.amazonaws.com., A 52.42.27.67 (115)
I've replaced my static IP address with A.B.C.D in the above. The nwserver software successfully resolves nwmaster.beamdog.net to address 52.42.27.67 but I then see no attempt to communicate with this address.

Kaltrip

I have a workaround. The nwserver is not making any requests to nwmaster.beamdog.net (52.42.27.67) but it is making outbound requests to an old Bioware address of 66.244.193.9. So what I've done is to hijack this request and to rewrite and redirect the packet to the 52.42.27.67 address. This then has the effect of making my server appear on the master list. I'm now trying to work out what I have done to my install to make this necessary as I have a report of another 74.8150 version Linux server working as expected.

I do the necessary rewrite and redirection using the firewall software running on my server. In case anyone is seeing a similar problem, this is the command I use:
/sbin/iptables -t nat -A OUTPUT -p udp -d 66.244.193.9 -j DNAT --to 52.42.27.6