Could not look up hostname - another possibility

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zomalaja

Could not look up hostname - another possibility

Post by zomalaja »

BAH - now i see that this is a known issue -
Summary 0002431: resolver problem: not resolving CNAME'd PTR's correctly

sorry



Heres the transcript of an email conversation I had with my bnc provider, look at the bottom for his conclusions. I anonymized everything but if it will help the developers i'd be glad to provide them with specifics.

> is from me, plain is from the shell provider admin


> Any idea why this private IRC server (Unreal 3.2.3) cannot find my hostname?

What's the value from unrealircd.conf?
Have you tried increasing the timeout?
dns {
nameserver XXX.XXX.XXX.XXX;
timeout 10s;
retries 2;
}
I really don't know why some vhosts don't resolve with Unreal.

> Changed timeout from 2s to 10s and rehashed,
>
> <01/18 - 13:09:56> -irc.xxxxxxx.net- *** Looking up your hostname...
> <01/18 - 13:10:35> -irc.xxxxxxx.net- *** Couldn't resolve your hostname; using your IP address instead


The only difference I see, is my hostname use CNAMES for the reverse DNS entry.

For example:
# set type=ptr
# ddd.ccc.bbb.aaa.IN-ADDR.ARPA
Server: dnsserver.net
Address: 127.0.0.1

Non-authoritative answer:
ddd.ccc.bbb.aaa.IN-ADDR.ARPA canonical name = ddd.ccc.bbb.aaa.provider.net
ddd.ccc.bbb.aaa.provider.net name = vhost.name.host


Versus a traditional entry:

# ddd.ccc.bbb.aaa.in-addr.arpa
Server: dnsserver.net
Address: 127.0.0.1

ddd.ccc.bbb.aaa.in-addr.arpa name = provider.net
ddd.ccc.bbb.aaa.in-addr.arpa nameserver = web1.provider.net
provider.net internet address = aaa.bbb.ccc.ddd

I submitted a ticket for them to point 'aaa.bbb.ccc.ddd' to provider.net using the 'normal' method, instead of using cnames. It might take 24 hours to update, once it's in place, I will then attempt to connect using that IP and see if DNS works or not.

Two possible outcomes:

1. IF DNS works for 'provider.net' and not other VHOST IP's, it would
make me think that it was Unreal resolver not recognizing 'Classless
in-addr.arpa Delegation'.

2. If DNS still fails, then I'm at a loss. Perhaps we can try switching to
a different nameserver.

Well I updated provider.net to the traditional method, and it worked perfectly.

So, it appears that the Unreal resolver doesn't handle 'classless reverse dns delegation'.
Syzop
UnrealIRCd head coder
Posts: 2179
Joined: Sat Mar 06, 2004 8:57 pm
Location: .nl
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Post by Syzop »

It is indeed exactly that.

3.2.4 will fix this (due to be released in 1-2 weeks).
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