Faulty IRC DNS lookup

I’ve been having some problems connecting to IRC through the miranda client on Win 7 lately.

Miranda features several “serverlists” for different IRC networks – QuakeNet in my case. Some of the lists work, some don’t, some work at some times. Now, upon clicking edit only one fixed web address shows up. The way this works is, the DNS server knows multiple IP subentries for those servers. You can check with some web-based lookup tools that show all of those entries. Windows’ own command (“nslookup <address>”) only shows the one delivered by the server, as it needs only one precise IP to communicate.

Multiple entries exist to balance load between servers, they are delivered round-robin. If you flush your dns cache locally (Win 7 wants you to do “ipconfig /flushdns” on the console in admin mode, for example) a new IP is acquired – and this one is ideally different from the one before. Now, because Windows does not clear the cache between requests for several logical reasons (it’s a cache, right?) the client program obviously also knows only one of the possible IPs. All the better if exactly that IP is down.

It took me quite some time to figure out where the problem was (all the while thinking there may be something wrong with the router or the net is just in a weird mood today). After checking the DNS entries sequentially using ping and a connection attempt through Miranda, I found to my surprise that while some lists work partially others are simply dead.

irc.quakenet.org 1/8 working Compilation of all subranges
se.quakenet.org 1/3 working
de.quakenet.org 1/2 working
uk.quakenet.org 1/3 working

Remember that this data is momentary from the time I checked the servers. The status might be different now. Anyways, this is some russian roulette!

The lists may fluctuate though, I am pretty sure I got a connection using the german list at some time. It is also possible, that the lists are updated dynamically from time to time, but I haven’t seen it so far.

Fixing this mess is quite easy: just edit or add a list in Miranda for the corresponding network and enter the exact IP. You best find that one yourself by pinging, start with one of the shorter lists you are comfortable with. You will experience trouble if that server goes down, but at least then you will know what the heck is wrong right from the start. Saves time and nerves.

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