Technology Insights

RackSpace Cloud DNS Round Robin DNS A Records

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.

Technology Insights

Windows Virtual PC DNS Not Working Over Shared Networking NAT

Windows Virtual PC is pretty slick for having virtual machines on a Windows 7 computer. I use it for multiple Linux virtual environments including Backtrack and CentOS on a  regular basis. One issue you may run into is that your wireless network card will likely not work in Linux so you will be required to use shared networking (NAT) instead. Below is information on what you will need to do to get shared networking (NAT) operational in Backtrack Linux.

Technology Insights

Install dig On Windows 7, Get dig Working On Windows 7 64-Bit OS

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.