Name Service in IPv6 Mohd Norman Maraddin

IPv6 and DNS  Assumptions : Everyone knows / has little knowledge on how to configure the IPv4 DNS

Basic Ideas   DNS in IPv6 is much like DNS in IPv4   Keep files and delegations as simple as possible.   Can use IPv4 as transport for DNS for now.   Modern versions of Bind will work – Bind9 is stable and works with IPv6.   There is work on dynamic DNS in progress, but we don’t need to worry about that for now.

Important Terms  A – address record maps a host name to 32-bit IPv4 address (Forward lookup)  AAAA – address record maps a host name to 128-bit IPv6 address (Forward lookup)  ip6.arpa – Reverse mapping name space for IPv6  ip6.int – Reverse mapping name space which has been deprecated but still maintained by some hosts

Platforms  FreeBSD or LINUX  Bind/DNS Version 9 with IPv6 support. Version 9 with IPv6 support.  Name Server Daemon (NSD) Latest - version Latest - version  Microsoft DNS Windows server 2003 Windows server 2003

Forward Lookup (AAAA)   Uses AAAA records for assign IPv6 addresses to names.   Multiple addresses possible for any given name – for example, in a multi-homed situation.   Can assign A records and AAAA records to a given name/domain.   Can also assign separate domains for IPv6 and IPv4.   Don’t be afraid to experiment!

Configuration – Sample Forward Lookup   ;; nav6.org (use your favorite naming scheme)   $TTL  IN SOA ns1.nav6.org. root.nav6.org. (   ; serial - YYYYMMDDXX   21600; refresh - 6 hours   1200; retry - 20 minutes   ; expire - long time   86400); minimum TTL - 24 hours   ;; Nameservers   INNSns1.nav6.org.   INNSns2.nav6.org.   ;; Hosts with just A records   normanINA   ;; Hosts with both A and AAAA records   rahmatINA   INAAAA2001:468:100::2   :: Separate domain   $ORIGIN ip6.domain.edu   cwtan INAAAA2001:468:100::1

Reverse lookup (ip6.arpa)   Reverses should be put in for both ip6.int and ip6.arpa domains.   The ip6.int domains has been deprecated, but some hosts still use them.   Can use same file for both – use notation and point to the same file in the named.conf file.

Configuration – Reverse Lookup   ;; rev (use your favorite naming scheme   ;; These are reverses for 2001:468:100::/64)   ;; File can be used for both ip6.arpa and ip6.int.   $TTL  IN SOA ns1.nav6.org. root.nav6.org. (   ; serial - YYYYMMDDXX   21600; refresh - 6 hours   1200; retry - 20 minutes   ; expire - long time   86400); minimum TTL - 24 hours   ;; Nameservers   INNSns1.nav6.org.   INNSns2.nav6.org.   INPTRnorman.nav6.org   INPTRrahmat.nav6.org   ;;   ;; Can delegate to other nameservers in the usual way   ;;

Sample configuration file (named.conf)   // named.conf (use your favorite naming scheme)   zone “nav6.org” {   type mater;   file “master/nav6.org”;   }   zone “ ip6.int" {   type master;   file "master/ rev";   };   zone “ ip6.arpa" {   type master;   file "master/ rev";   };

How to test?  Try resolving an IPv6 name – ping the an IPv6 domain name Try to resolve using nslookup command: Try to resolve using nslookup command: nslookup v6training.nav6.org ornslookup v6training.nav6.org or ping v6training.nav6.org ping v6training.nav6.org Should see that the name being resolved to IPv6 addressShould see that the name being resolved to IPv6 address

Issues  IPv6 address is long and this create space for human error especially in the reverse lookup

References 