I typically use Amazon’s AWS EC2 cloud services which include Route53 for DNS however I have certain clients that prefer RackSpace and therefore require RackSpace Cloud DNS services. One of the primary reasons for not just using an external DNS service such as Amazon’s Route53 DNS service is because when you setup large cloud deployments you typically are going to need internal DNS entries for communication between cloud instances and DNS services such as Route53 will not respond externally to RFC1918 or private IP space for those DNS entries. Anyhow one thing that is well documented or easy to accomplish on Route53 is creating A records with multiple IP’s for round robin DNS which provides a cheap easy to configure load balancing of sorts for different services such as MySQL. I could not find any documentation or mention of round robin DNS setup on RackSpace Cloud DNS so I wanted to explain how I was able to accomplish this.
Recently I wrote an article about using dig and whois on Windows 7. If you want to review the previous article click here. A question recently came up about how to whois .de domains. For each TLD or Top Level Domain such as .de, .co.uk, .mil, .ru, etc. you will need to use a different whois server. Below there is information about attempting to run whois against google.de without specifying a different whois server followed by information using the proper whois server.
I have been wanting to get the use of dig on Windows 7 for awhile but hadn’t taken the time to do so until now. The problem is nslookup is not as helpful in terms of TTL of zone files, etc. and while you can accomplish your tasks with nslookup using dig makes life much easier on Windows 7 when troubleshooting DNS type issues. The other night I was in the middle of a time critical launch of a new web cluster and needed dig on the Windows 7 laptop I was working on so I decided to get it working while I was waiting for some data to transfer. I actually had slipped on setting the TTL, which was for a single sub domain that was part of the transfer, from a TTL of a entire day (86400 seconds) to a TTL of one hour (3600 seconds). Anyhow below is more information on installing dig on a Windows 7 computer.
Installing dig on a CentOS Linux server is easy with yum. Dig is actually a bind tool so you will be required to install some bind libraries along with the bind utility package.
- [root@server ~]# yum install bind-utils
Now you can run something like the below using dig to find MX records.