I just came across Rick Moen’s Preventing Domain Expiration article. Rick did a great job with the article, and it’s cool to see that they took my domain-check shell script and implemented it in Perl. The Perl version supports for TLDS, and contains a bit more functionality than the bash implementation. If I get some [...]
While perusing my BIND query logs, I came across the following entry:
Nov 21 12:34:41 dns named[780]: [ID 866145 local0.info] client 1.2.3.4#32773: query: yikes.com IN MX -E
All of the text up to the record type (MX in this case) made sense, but I had no idea what the “-E” meant. Being the curious person I am, [...]
While debugging a DNS problem a few weeks back, I needed a way to measure the time it took a name server to respond to a DNS request. After poking around the OpenBSD ports collection, I came across the nsping utility. Nsping queries a DNS server passed on the command line, and reports the time [...]
I support BIND on a few servers, and when run as a caching name server, BIND can consume a fair amount of memory if you have lots of clients. There are two ways to restrict the amount of memory BIND uses. The first method, which is described in Pro DNS and BIND, is to set [...]
I recently started supporting several DNS servers running BIND 9. To ensure that these server are up and operational at all times, I wrote a small shell script named dns-check to test the operational state of each server. The script takes a file as an argument, and each line in the file contains the [...]
If you run DNS and SMTP servers, you probably know how important it is to validate the configurations used by your SMTP relays and DNS servers. Broken configurations can lead to clients not being able to find your website, open mail relays, unroutable mail, and your domain being blackholed by the Internet. Luckily there are [...]
