[SR-Users] dns queries on ipv6 addresses

[Alex Hermann]

On Thursday 25 October 2012, Juha Heinanen wrote:
> an ipv6 address can thus never be a valid domain name.  an ipv4 address,
> on the other hand, is syntactically valid domain name and perhaps
> someone has populated their local name server with such names.

But the application (kamailio) should not attempt a DNS lookup if the hostname 
is an IP(v4/v6) address, from RFC1123, section 2.1:

========
Whenever a user inputs the identity of an Internet host, it SHOULD
be possible to enter either (1) a host domain name or (2) an IP
address in dotted-decimal ("#.#.#.#") form.  The host SHOULD check
the string syntactically for a dotted-decimal number before
looking it up in the Domain Name System.
.
.
.
However, a valid host name can never
have the dotted-decimal form #.#.#.#, since at least the
highest-level component label will be alphabetic.
========

It would be nice if Kamailio refuses to lookup both IPv4 and IPv6 addresses 
independent of the address family of listening sockets (see my emails about 
dispatcher and IPv6, where DNS lookups on IPv6 addressed are only skipped if 
Kamailio is listening on an IPv6 address).


-- 
Greetings,

Alex Hermann