reversed behavior with nsswitch.conf

[Alexander Leidinger]

Hi,

yesterday I debugged a mail problem where the reverse DNS of the receiver is
somewhat fucked up (for one receiver the DNS resolving chain was: HostA ->
IP-A -> HostB -> IP-B -> HostB, for the other receiver there was no reverse
DNS).

Sendmail doen't like this, but there are ways to circumvent this. So I added
the hosts in question to /etc/hosts (nsswitch contains "hosts: files dns"),
and thought this will solve it. It didn't.

A temporary (as in "to get those 10 mails out") work-around of "hosts: files"
proved that the solution of adding the hosts to /etc/hosts works as expected.

The current solution for the general case is to use "hosts: dns files". It
gets the correct values for the buggy remote hosts from /etc/hosts, and
averything else from DNS.

So it seems the order of the use of the entries in nsswitch.conf is reversed.

I noticed this on a 6.0 system. I can't test this on a -current system right
now (maybe tomorrow or at the weekend), and I don't have a RELENG_6 system.

So if someone can confirm if this bug is visible on -current and on RELENG_6:
 - a fix can be MFCed if it is fixed in -current
 - someone could try to fix it if the same problem exists in -current
 - an errata can be added to the release notes of 6.1 if it isn't
   fixed until the release (that's the reason why I CCed re@)

Bye,
Alexander.

-- 
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