While investigating a performance issue a few weeks back, I noticed that a couple of our Solaris hosts were sending 10s of thousands of DNS requests to our authoritative DNS servers. Since the application was broken and unable to cache DNS records, I decided to configure a local caching only DNS server to reduce load [...]
While debugging a DNS issue this week, I wanted to run my trusty old friend nsping on my Linux desktop. I grabbed the source from the FreeBSD source site, checked to make sure the bits were legit, then proceeded to compile it: $ make cc -g -c -o nsping.o nsping.c In file included from nsping.c:13: [...]
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 [...]
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 [...]
