Most of you reading this will already know what DNS Scavenging is. For those of you that don’t it is a feature of Windows DNS servers which allows you to automate the deletion (scavenge) of outdated DNS resource records. It sounds simple enough and it is once you decipher Microsoft’s cryptic descriptions, but to the uninitiated it is just plain confusing and often leads to unpredictable results. This article will attempt to simplify how DNS scavenging works. Enabling DNS Scavenging on Zones The first thing we need to do is enable Scavenging. This is done separately for each DNS zone.
Recently I was doing a bit of promotional work for my blog by participating in some IT related forums. I was going through the post as you do when an interesting question came up. The poster was reading up on about DNS Zones, what their purpose is and how they work. He was having trouble understanding the following paragraph in a study book he was reading: A DNS zone contains all the domain names the domain with the same domain name contains, except for domain names in delegated subdomains. For example, the top-level domain ca (for Canada) has subdomains called ab.ca, on.ca, and qc.ca, for the provinces Alberta, Ontario, and Quebec. Authority for the ab.ca, on.ca, and qc.ca domains may be delegated to nameservers in each province. The domain ca contains all the data in ca plus all the data in ab.ca, on.ca, and qc.ca. However, the zone ca contains only the data in ca (see Figure 2-10), which is probably mostly pointers to the delegated subdomains. ab.ca, on.ca, and qc.ca are separate zones from the ca zone. Can you understand that?? No wonder he was having trouble,