Networking/NameResolution/DNS

Client operations

Client software requires at least A and AAAA queries for dual-stack operation. Name resolution libraries have different options to handle that.

Name resolution results order

• When IPv4 and IPv6 is available, IPv6 is preferred by default.
• When one of the protocols is known to be unavailable, IP

Example: Name server configuration (bind)

named.conf:

include "/etc/named/zones.test.master";

zones.test.master:

zone "example.net" {
	type master;
	file "/etc/named/master/example.net";
};

master/example.net:

$TTL 10m
@               SOA     router hostmaster 2012121400 1d 15m 4w 10m
;                       nameserver e-mail serial refresh retry expire negative-ttl

@               NS      router

router          A       10.0.17.1
                AAAA    2001:15c0:6753:17::1
station         A       10.0.17.2
                AAAA    2001:15c0:6753:17:5054:abff:fe17:222

www             CNAME   station