Zugschlusbeobachtungen

This article was updated, and the issue seems solved. Please look at the last paragraph before adding comments.

Exim has the habit of trying to find out about its host names and IP addresses when it starts up. This has, in the past, been an issue for the Debian packages, since a Debian system might be on a dial-on-demand modem line with expensive costs and thus should not do unnecessary DNS lookup when the MTA is started.

This article tries to describe the issue and which countermeasures debian took, and asks for tips how to solve this in the case of IPv6, where our past measures unfortunately do not directly apply.

I’d like to solicit opinions from people who are more experienced than me with Unix, the local resolver library including /etc/hosts and /etc/nsswitch.conf, DNS, and - especially - the customs that apply on a system running IPv6.