Table of Contents Add a DNS delegation to IPv6 and IPv4 IPv4 IPv6 Add a DNS delegation to IPv6 and IPv4 You can't edit the reverse of IPv4 /27 blocks & the IPv6 blocks (/48 - /56 - /64) directly in the console. Therefore you'll have to delegate your subnet to your nameservers. It will delegate the task to propagate DNS reverses of your IPs on the Internet to your servers. You will need two DNS servers for redundancy. You can delegate the subnets directly in your account. At first you'll have to go to the network configuration in your account: “Server” > “Network configuration”: You'll have to click then on the cogwheel next to your IP block. Click on “Edit nameserver delegation” then: You'll have to repeat this for all your /27 IPv4 blocks. For IPv6 it will be enough to delegate your /48 as all subnets in your block will automatically configured to the same nameservers. IPv4 It is important that you make your DNS configuration according to RFC 4183. Here is an example BIND configuration for the block 62.4.10.0/27: 0-27.10.4.62.in-addr.arpa. 86400 IN SOA ns1.mydns.net. hostmaster.mydns.net. ( 2013121407 ; Serial 10800 ; Refresh 1800 ; Retry 604800 ; Expire 86400 ) ; Minimum TTL 0-27.10.4.62.in-addr.arpa. 86400 IN NS ns1.mydns.net. 0-27.10.4.62.in-addr.arpa. 86400 IN NS ns2.mydns.net. 1.0-27.10.4.62.in-addr.arpa. 86400 IN PTR toto.domaine.com. The line SOA indicates the authoritative server for the IP block, The lines NS indicates the propagating DNS servers for the concerned IP block. The lines PTR indicates the revers of the indicated IP, here 62.4.10.1. If your IP Block is not a /27 but a different size, you'll need to adapt your configuration according to it. IPv6 The configuration of IPv6 is done in the same way. You have to create a reverse zone directly on your DNS server. Here a BIND example for the zone 2001:bc8::3398::/48: ; ; 2001:bc8:3398::/48 ; ; Zone file built with the IPv6 Reverse DNS zone builder ; http://rdns6.com/ ; $TTL 1h ; Default TTL 8.9.3.3.8.c.b.0.1.0.0.2.ip6.arpa. IN SOA ns1.domain.fr webmaster.domain.fr ( 2016071503 ; serial 1h ; slave refresh interval 15m ; slave retry interval 1w ; slave copy expire time 1h ; NXDOMAIN cache time ) ; ; domain name servers ; @ IN NS ns1.domain.fr. @ IN NS ns2.domain.fr. ; IPv6 PTR entries 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.9.3.3.8.c.b.0.1.0.0.2.ip6.arpa. IN PTR toto.domain.fr. In case of need, you can use the utilities available at rdns6.com to facilitate the generation of your zones.