The current IETF recommendation is to use AAAA (Quad A) RR for forward mapping and PTR RRs for reverse mapping when defining IPv6 networks. The IPv6 AAAA RR is defined in RFC 3596. RFC 3363 changed the status of the A6 RR (defined in RFC 2874 from a PROPOSED STANDARD to EXPERIMENTAL due primarily to performance and operational concerns. Tech Info - IPv6.
name ttl class rr ipv6 joe IN A 2001:db8::1
If multiple addresses are defined with the same name then BIND will respond to queries with a list of the addresses but the order may change on sucessive queries depending on the value of the rrset-order statement in BIND's named.conf file. The default order is cyclic or round-robin. The same IP may be defined with different names. IP addresses do not have to be in the same subnet or use the same global routing prefix. The order in which AAAA RRs are defined is not significant but it may be easier to define them in either an ascending or descending order of IP address since this can prevent unintentional duplicate definitions. Since the ipv6 field is an address not a name there is no terminating dot. The following zone file fragment illustrates various uses of the AAAA RR.
; zone fragment for example.com $TTL 2d ; zone default = 2 days or 172800 seconds $ORIGIN example.com. .... joe IN AAAA 2001:db8::3 ; joe & www = same ip www IN AAAA 2001:db8::3 ; functionally the same as the record above www.example.com. AAAA 2001:db8::3 fred 3600 IN AAAA 2001:db8::4 ; ttl =3600 overrides $TTL default ftp IN AAAA 2001:db8::5 ; round robin with next IN AAAA 2001:db8::6 mail IN AAAA 2001:db8::7 ; mail = round robin mail IN AAAA 2001:db8::32 mail IN AAAA 2001:db8::33 squat IN AAAA 2001:db8:0:0:1::13 ; address in another subnet
IPv6 and IPv4 RRs can be freely mixed in the zone file as shown the following fragment:
; zone fragment for example.com $TTL 2d ; zone default = 2 days or 172800 seconds $ORIGIN example.com. .... www IN A 192.168.0.3 mail IN A 192.168.0.32 www IN AAAA 2001:db8::3 mail IN AAAA 2001:db8::32
Blank name substitution can also be used in mixed configurations if this is more convenient or understandable:
; zone fragment for example.com $TTL 2d ; zone default = 2 days or 172800 seconds $ORIGIN example.com. .... www IN A 192.168.0.3 IN AAAA 2001:db8::3 mail IN A 192.168.0.32 IN AAAA 2001:db8::32
In both above fragments it is assumed that the hosts are running dual (IPv4/IPv6) IP stacks.
3 reverse map
4 dns types
5 install bind
8 dns records
12 bind api's
13 dns security
bits & bytes
notes & tips