A standard DNS "A" type record allows a domain name to be converted into an IP address and is known as a forward mapping. A Reverse DNS Record does the opposite and allows an IP address to be converted into a hostname.
These Reverse DNS Records have several names. They are sometimes known as Reverse Maps, Reverse Mappings or by there Technical Name as "PTR" records.
These records are not strictly necessary for the server to function. However, many spam email filtering and other security systems check for the existence of the Reverse DNS records and may be more likely to classify traffic from the server as dubious without a reverse DNS record.
Memset automatically sets a reverse record for every primary IP address allocated to a server, these default records are the same as the default hostname supplied with the server. For a server with the name examplaaa1 they would be as follows:
Any additional IP Addresses allocated to a server, do not come with a default Reverse DNS Record set.
It is possible to modify the default Reverse DNS Records for all IP addresses assigned to your Memset account using the the Reverse Map Names page in your DNS Manager.
Modifying a Reverse DNS Record
The "Reverse Map Names" page contains every IP address that has been allocated to a server in the account, along with it's default hostname and other information. An example of this can be seen below;
The columns in the example are as follows:
Server Name - This is the designation given to the server by Memset when it was ordered.
Hostname - This is the default / original hostname given to all server's when they are ordered. It is also the default reverse mapping given to the primary IP address. This may vary from the hostname that has been set on the server if the hostname has been changed.
IP Address - The IP address that these settings relate too.
Primary IP - This indicates whether the listed IP is the servers primary IP address. The primary IP of a server will usually be the IP that outgoing connections i.e. sending / relaying emails, will be made on. Therefore, this is the most important IP to set a reverse mapping on.
Reverse Map Name - This field contains the hostname that will be set as the reverse map. The drop down list will contain a list of every domain that has been added to the DNS manager of the account. It is not necessary to choose one of these as the field can be edited and any custom hostname can be entered.
Once any changes have been made select the "Update" button for the Reverse DNS Records to be Updated and Saved.
DNS Record Updates
The Memset Nameservers are updated once every 15 minutes with any changes to the DNS Records, as such please allow upto 15 minutes for changes to be applied on our Namservers after they have been saved in your Control Panel.