On Tue, Jul 25, 2017 at 11:20:57PM +0200, u-hd-p...@aetey.se wrote: > > Given that SRV records as a matter of fact are defined via A[AAA] records, > (and given that A lookups historically _are_ interposed by /etc/hosts) > what says that /etc/hosts are to be ignored if an A lookup happens as > a consequence of an SRV one?
Actually, I do not think that A lookups historically are interposed by /etc/hosts. I think that it is more accurate to say that historically there have been functions called gethostbyname(3) and getaddrinfo(3) which mediated by the definitions in /etc/nsswitch.conf choose whether to do files, DNS, LDAP, YP, etc. In all of the implementations that I've seen, once you call into one of those modules, it will either return an entire answer back up or fail which allows the NSS framework to pass control to the next module. In some cases, mostly with YP there are ways to mix the modules a bit but those are mostly used for the passwd and group maps rather than the host map. -- Roland C. Dowdeswell