While setting up ZNC, a BNC for those who had not guessed, I ran into the following error

<*status> Cannot connect to IRC (Cannot assign requested address (Is your IRC server's host name valid?)). Retrying...

Googling for the exact error did not help much either, since most I got were pastebins with just that error repeated a few times. Quite useless. Next stop was the ZNC IRC channel on EFnet. Turns out I was not the first with this issue, the solution was right in the topic (newlines added by me)

* Topic for #znc is:
   Help on restoring www.znc.in is welcome
 | ZNC 0.202: http://tinyurl.com/znc-0202
 | Nightlies: www.znc.in/nightly
 | Don't PM @s
 | Try: /znc setbindhost 0.0.0.0

Indeed, the last bit was meant for the likes of me. Issuing that command fixed the issues

/znc setbindhost 0.0.0.0
/msg *status jump

To make it permanent, I stopped ZNC and added the following line for every user in my configs/znc.conf

BindHost   = 0.0.0.0

Then just save and start up ZNC.

A commenter notes he had it working on Debian Squeeze, but it broke in an upgrade to Wheezy. I had this issue too, it seems the lines added to znc.conf had disappeared, so I had to readd them.

Another commenter notes Wheezy has v0.206 and that the bug was fixed in v1.0. If you still experience this issue, upgrading is the way to go!