Extra Services: 
Reverse DNS
DNS is the backbone of the internet – it’s what binds names (such as www.hahosting.com) to IP addresses,
allowing servers and computers to talk to each other.
Reverse DNS (or rDNS) is the opposite to how normal DNS works, instead of translating a host name into
an IP address, rDNS translates an IP address into a host name. When a domain name has a valid rDNS, it
can also be access by just using the IP address – for example if you type “188.94.74.11” in your web
browser you will be redirected to our www.hahosting.com website.
Why would I want Reverse DNS?
Most commonly rDNS is used for mail servers; when an mail server sends out an email for a domain, the
receiving server commonly does a “reverse lookup” on the MX record to determine if the IP address
sending the email is actually the server it’s supposed to be. Email systems such as AOL, 1&1 and even
our own hosted email service on TheVirtualCloud.com now use this as a basic check before accepting email.
For example:
If domain
bloggs.com has a MX record of
mail.bloggs.com, with an IP address of
1.2.3.4, and that server sends an email to the mail server of
fred.com, fred’s email server
will check the MX record of
bloggs.com (
mail.bloggs.com) to ensure it’s IP address actually
is
1.2.3.4, if it’s not it may block the message from being accepted.
Additionally some security software and enterprise management systems use rDNS to ensure the IP address
of the server connecting is actually the server as specified in it’s hosts file.
The Sheffield Data Centre and rDNS
We offer Reverse DNS to all customers of the Sheffield Data Centre free of charge. Any customer who
has servers hosted with us (or VM servers with
www.hahosting.com)
can have their IP address registered against a hostname.
Simply raise a support ticket with us once your server or colocation is live, and we’ll sort the rest.
Redundancy & Security
We operate a redundant pair of name servers on our VMware cluster, with each name server running on a
separate node, each VMware server is connected to a different physical switch, and each physical switch
is connected to a different interface on the firewalls.
Servers are only allowed to accept DNS updates from our management network, so only genuine updates can
be propagated to the internet as a whole. As members of RIPE, our DNS servers are registered and only
our servers are authoritive for our IP address ranges.
Contact us
To setup your Reverse DNS in the Sheffield Data Centre, call us on 0114 228 0022 or use
our
online contact form.
All prices exclude VAT.
Reverse DNS or rDNS or PTR services offered by the Sheffield Data Centre.