reverse dns for IPV6 ranges
Spain, Dr. Jeffry A.
spainj at countryday.net
Mon Mar 5 21:15:53 UTC 2012
> Can anyone help me with its experience on reverse dns for IPV6?
> Presently, when we reverse an IPV4 subnet for clients, we configure all the reverse for the whole subnet.
> It is a lot of PTR's but perfectly manageable.
> With IPV6, the number of IP's that we will receive is amazing....
> So...it seems impossible for every single IPV6 inthe range to configure a PTR.
> So...what to do?
> What is the common practice?
> What is possible with BIND?
For our IPv6 address space 2001:4870:20ca::/48, I created a reverse lookup zone a.c.0.2.0.7.18.104.22.168.0.2.ip6.arpa and arranged for delegation from our ISP. I included PTR records only for those hosts accessible from the outside. Internal DNS is Windows Active Directory integrated. Here's a sample from the zone file, which contains about 25 PTR records in all:
$TTL 3600 ; 1 hour
a.c.0.2.0.7.22.214.171.124.0.2.ip6.arpa IN SOA ns1.countryday.net. hostmaster.countryday.net. (
2012030101 ; serial
86400 ; refresh (1 day)
3600 ; retry (1 hour)
1209600 ; expire (2 weeks)
3600 ; minimum (1 hour)
a.5.6.9.f.9.e.126.96.36.199.e.f.a.0.8 PTR ns2.countryday.net.
2.9.1.f.1.d.2.1.b.f.7.5.7.f.8.0 PTR ns1.countryday.net.
I would also be interested in hearing about the practices of others. Jeff.
Jeffry A. Spain
Cincinnati Country Day School
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