July 8, 2014

Some tips when updating DNS Records

e-284DNS can get the best of anyone.

There are a few quick and simple rules of thumb though. We see these common mistakes here every day, and always try to help clients fix them. So if you are working with DNS records , follow these guidelines.

 

1. Your @ (blank record). This is used when typical when someone uses http://<your-domain> instead of http://www.<your-domain> to go to your website. EG http://elive.net
This should always be an IP address and you should not use it as a CNAME if you use email on the same domain. It can result in people getting emails from you with the servers domain appended to your email address, so the person cannot reply EG: they will get and email from <you>@example.com.mail.elive.net
** Always make it an IP address

2. MX records. Your MX record should not be an IP address, it should be a hostname. While it might work as an IP , it is against RFC’s and some mail servers will reject mail from you if you MX record is an IP address as it considers you a possible spammer.
Instead setup an A records to point to the IP (it can have any name) and use that hostname as the MX Record. Examples
The Wrong Way : elive.net  MX 91.223.9.45
The Correct Way : A record first : >> incoming.elive.net  A  91.223.9.45  Then MX record >> elive.net MX incoming.elive.net
Note: the A record of incoming.elive.net could be anything. I could have named it djcysyd.elive.net , as link as I use the same hostname in the MX record. Some people think it HAS to be mail.elive.net. That is not true, computers don’t care what the word is.
** Do not use the IP address as an MX record

3. MX records Part II – Values of MX.
Each MX record has a value associated with it (i didn’t use any in number 2 above for simplicity). The value determines what is the primary server and what is the secondary and so on. If, for example, the primary is offline, email will be delivered to the secondary and queue there until the primary comes back online.
The lowest value is picked first. So if you have 3 records , with values of 3, 47 and 99, then the one with a value of 3 is picked first.
These numbers do not have to be certain value, like 10, 20 , 30. They can be 1,2,3 or 100,500,1000. DNS only cares about the order and the lowest one it can deliver to.
Do not make all servers of equal value unless they all are primary servers. Also do not mix servers from different ISP’s unless you are told to do so. EG: You cannot use our server as backup if you host with Outlook.com, we are not configured to act as a backup for them and vice versa.
** MX record value can be any number, as long as the order is kept

4. SRV records
These are special records and have a very specific format, you cannot set them up with just a hostname. The example setup is:
_SERVICE._PROTOCOL SRV PRIORITY WEIGHT PORT TARGET
_autodiscover._tcp  SRV 100 1 443 autodiscover.DOMAIN

So, in our DNS Administration system, you would put “_autodiscover._tcp” in the left box, then pick SRV as a record type and put “100 1 443 autodiscover.DOMAIN” in the right box
(without the quotes)

Examples of DNS records can be viewed in our knowledge base here

So, if you ever edit your records and see a Red dot beside any of them, it means there is an issue with that one. If in doubt, feel free to ask us and we will help

Your Elive™ Support Team