Troubleshooting problems connecting to your favourite MUD / MMORPG
Are you having trouble connecting to your MUD? Before you post a message on the forum about a "client bug" - read the posting below. It will help you understand the various steps involved in connecting to a multiplayer game, and how to interpret various sorts of error messages.
First, a network diagram, to illustrate the path that a network connection is likely to take:
Let's take each step at a time ...
Resolve the Domain Name
One of the first things your client has to do is "resolve the domain name". What this means is that an alphabetic name (like smaug.org) has to be converted to a network address (like 188.8.131.52). Packets that travel over the network are addressed by number (eg. 184.108.40.206) not by name. The use of domain names is a convenience for humans.
To convert a name, the client has to contact a Domain Name Server (DNS), sending it the name it wants resolved. If possible the server replies with the name converted into a number.
You can see from the network diagram above that the Domain Name Server (DNS) is number 6 on the list of steps, so there are quite a few things that can go wrong before the domain name is resolved.
Firewall (item 2 on network diagram)
Many PCs these days have a firewall installed by default, or you may have chosen to install one yourself, or upgrade the existing one. Attempting to use your client, for the first time, to access the Internet (including the DNS) may result in a warning dialog box like this (the IP address will be different):
It is important to click "Allow" and preferably "Save the answer as a permanent rule", otherwise you will not get much further using your client to access the Internet. If you don't see a dialog box then it is possible you (or someone else) denied access previously, and it has been saved as a rule in the firewall already. If this happens you will probably see a message like this in MUSHclient:
Unable to connect to "Realms of Despair", code = 10051 (Network is unreachable)
The message "Network is unreachable" suggests that the firewall has denied access to the network to this program. In this case you would need to go into your firewall configuration, find the relevant rule, and modify it:
I notice that MUSHclient has been blocked by someone, so I click on Edit to modify the rule:
Change the rule to Allow, and click OK to save and OK again to save the changes to the firewall rules. Your firewall may be different but the same general principles will apply.
Router / modem (item 3 on network diagram)
The next link on our chain is the home router / modem (or cable modem) which connects our PC to the Internet. Personally I have two boxes, one is the modem supplied by the cable company, and the other is a home router, which lets me share the Internet connection between multiple PCs. Sometimes I find that these devices fail, and powering them off and back on can help restore a lost connection. If I turn off my router, and try to connect I get this error message:
Unable to connect to "Realms of Despair", code = 10060 (Connection timed out)
Notice the different message compared to the firewall problem. This time it timed out (that is, got no response) while trying to connect.
A further possible problem is that routers often have their own firewalls. You may need to configure the firewall to allow outwards access from your PC to the MUD. However it is unlikely your router will not allow you to access your DNS server, otherwise you would not get much network browsing done at all.
If you have a dial-up connection, you may quite likely not have a router, but only a modem, in which case we move onto the next step ...
The next item to check is your modem, whether it be a cable modem, ADSL modem, dial-up modem, or some other device. If it is a dial-up modem, check it is connected. Reconnecting, or powering the modem off and on again can be helpful. The symptoms of a problem with the modem are:
- Cannot connect to any sites on the Internet at all (eg. in your web browser)
- Cannot send or collect mail
- Still able to connect to other PCs on the home network (if any)
Internet Service Provider (ISP) - (item 4 on network diagram)
The next step in the network diagram is your ISP. This is your gateway to the "main" internet from your home / office / school. Potential problems with the ISP are:
- Account not paid (so they suspended your access)
- Allocated time up for today (eg. you used up your 2 hours' allowance).
Internet Service Provider Firewall - (item 5 on network diagram)
ISPs can also have their own firewalls. In the case of businesses or schools these may well be configured to stop employees / students playing network games. Symptoms of this are:
- You can browse the Internet with your web browser
- You can send and receive mail
- You cannot connect to your favourite MUD / MMORPG.
In this case there probably isn't much you can do - attempting to ask your boss to let you play a MUD while you are supposed to be working may not be a smart career move.
Domain Name Server (DNS) - (item 6 on network diagram)
Finally we should be ready to resolve the domain name - that is, convert "smaug.org" to "220.127.116.11" or whatever number it is. It is possible for DNS servers to go down, they are a PC like anything else, however generally speaking people who provide DNS servers provide backups (so you should see a list of DNS server addresses in your network configuration). However if you have misspelt the domain name you are likely to see an error message like this:
Unable to resolve host name for "smaugg.org", code = 11001 (Host not found)
Notice the misspelling of smaug.org, resulting in a message that it cannot "resolve host name". If you get this message you may want to check your spelling, and check that the domain name still exists. For a really old game it is possible the name has been allowed to expire.
If we successfully resolve the domain name, you should be able to see the resolved IP address in MUSHclient, like this:
Notice the number 18.104.22.168 in that dialog box. That shows we have successfully resolved the domain name. Now to actually connect to the world ...
Connect to the game
Now that we have a domain name resolved we can move onto actually connecting to our game. In the case of MUSHclient it caches the IP address, so that if you disconnect from the game, and then reconnect (without closing MUSHclient) it bypasses the step of getting the domain name resolved and uses the cached IP address.
Many of the steps described above also apply to actually connecting to the game, except we will be contacting a different "port" number (the game port) and a different IP address (the game IP address rather than the domain name server IP address). These differences may make the various firewalls described earlier react differently.
MUD game router - (item 8 on network diagram)
The next hurdle for our connection attempt is to get past the router at the game server end. If you are just setting up a new game you may need to read up on Port Forwarding. One site to look at is http://www.portforward.com/ - this has information about configuring routers to port-forward. Normally players of games don't need to concern themselves with this, however if you are trying to get a server to work, you should pay attention to the detail there.
MUD game firewall - (item 9 on network diagram)
A further hurdle, if you are setting up your own game, is to configure your PC (or Linux) firewall to allow incoming connections to your game. The default may well be to refuse them.
Game server - (item 10 on network diagram)
Finally we have reached the game server - but is it up? Servers (and PCs) crash. If everything else looks OK but you get a message like this:
Unable to connect to "Realms of Despair", code = 10061 (Connection refused)
This could simply mean the MUD has gone down and is being rebooted. One thing to try is MUD Connector which, amongst other things, allows you to check if the MUD is up. If it is down, there isn't much you can do except patiently wait for the admins to fix the problem.