UnrealIRCd Forums

I'm having a problem where the IRC server is missing the resolution of a lot of the IP's that connect. The service is able to resolve some names, it's missing about 1/2 from what I can see now. This problem seems to be fairly recent. month or two from what was reported.. though I can't pin down the day it started... I'll look through the logs and see what I can find.

When I take the IP and reverse it in NSlookup (on the same names server) it resolves, so i know it's not the DNS server. The names server is a BINDS server running on the same box.

I've cleared the dns cache. It catches some names again, just not all.

I'm running the latest release version of unreal(3.2.2). A few external modules, but none that deal with dns.
(activeusers, and a custom module by syzop)

The OS is Debian - Testing distribution.

DNS command results from the server

[7:43pm] -> Server: dns
[7:43pm] -Irc.matridom.ca- Ca 4204 Cd 4163 Ce 4080 Cl 0 Ch 10:1762 Cu 1772
[7:43pm] -Irc.matridom.ca- Re 1849 Rl 7927/4683 Rp 15843 Rq 10855
[7:43pm] -Irc.matridom.ca- Ru 0 Rsh 16 Rs 19689(4418) Rt 104

[7:44pm] -> Server: dns i
[7:44pm] -Irc.matridom.ca- Nameserver list has 2 server(s):
[7:44pm] -Irc.matridom.ca- 0. 192.168.0.6
[7:44pm] -Irc.matridom.ca- 1. 206.191.0.140
[7:44pm] -Irc.matridom.ca- retrans=5 s, retry=4 times
[7:44pm] -Irc.matridom.ca- Default domain name: private.net
[7:44pm] -Irc.matridom.ca- End of info.


On a side note... is there a list of the flags I can use with /dns ?

Matridom wrote:On a side note... is there a list of the flags I can use with /dns ?

Yeah, /HELPOP DNS should tell you. (You'll need to type /HELPOP ?DNS if you have umode +h set.)

Unfortunately, I can't help you with the rest of your problem, sorry.

Did you test both DNS servers with a name that failed to resolve?
I don't recall 100% what happens with 2 nameservers, but I think it sends request to both to them (in parallel) and takes the reply of whichever answers first.

Personally, I'm running 3.2.2 (and recently 3.2.1) on Debian/testing too, with a dns server on the same machine.. Also a similar setup on another machine on the LAN: debian/testing with the nameserver being some other host on the lan, both resolve names just fine (not that this means there isn't a bug, but..).

Coming back at my previous point, perhaps you could try getting rid of 1 nameserver in /etc/resolv.conf & restart the ircd and see what happens? I'm sure there are more people with 2 nameserver setups so I don't think this is necesarily a problem, but perhaps it helps....

Syzop wrote:Did you test both DNS servers with a name that failed to resolve?
I don't recall 100% what happens with 2 nameservers, but I think it sends request to both to them (in parallel) and takes the reply of whichever answers first.

Personally, I'm running 3.2.2 (and recently 3.2.1) on Debian/testing too, with a dns server on the same machine.. Also a similar setup on another machine on the LAN: debian/testing with the nameserver being some other host on the lan, both resolve names just fine (not that this means there isn't a bug, but..).

Coming back at my previous point, perhaps you could try getting rid of 1 nameserver in /etc/resolv.conf & restart the ircd and see what happens? I'm sure there are more people with 2 nameserver setups so I don't think this is necesarily a problem, but perhaps it helps....

I'll try that this weekend when the chat server is quiet and see what occures. The external DNS server is not necessairy, i tend to run everything internaly. I'll let you know what happens.

**update**

I restarted the server with just one DNS server configured. Seems to be working now. I'll keep ya's up to date over the next several days to see if it's properly corrected

It appears that my issue is still unresolved. The server was restarted to 1 DNS server yesterday morning. Here are the results from the past 48 hours..

[10:06pm] -> Server: dns
[10:06pm] -Irc.matridom.ca- Ca 115 Cd 85 Ce 85 Cl 0 Ch 0:66 Cu 66
[10:06pm] -Irc.matridom.ca- Re 36 Rl 218/128 Rp 330 Rq 280
[10:06pm] -Irc.matridom.ca- Ru 0 Rsh 1 Rs 330(50) Rt 1
[10:06pm] -> Server: dns i
[10:06pm] -Irc.matridom.ca- Nameserver list has 1 server(s):
[10:06pm] -Irc.matridom.ca- 0. 192.168.0.6
[10:06pm] -Irc.matridom.ca- retrans=5 s, retry=4 times
[10:06pm] -Irc.matridom.ca- Default domain name: private.net
[10:06pm] -Irc.matridom.ca- End of info.


I wrote a routine that polls the results from my database for the last 2 days

resolved IPs: 210 unresolved IPs: 40 unresolvable IPs: 26 Errored IPs: 14

and if we move it back another day for 3 day results..

resolved IPs: 338 unresolved IPs: 62 unresolvable IPs: 37 Errored IPs: 25