Archive for June, 2011

Figuring out if a Linux executable supports a configuration directive

While debugging a problem last week I needed to quickly see if a version of bind supported the edns-udp-size configuration directive. Since RHEL3, RHEL4 and RHEL5 ship with different releases of Bind, I needed to see when this directive was introduced (EDNS was introduced in Bind 9, and the directive appears to have been there […]

Would you be interested in RFC cliff notes?

I’ve been toying with the idea of reading one RFC a week and developing cliff notes so I can remember everything I read down the road. While I can always recall WHERE I read something, sometimes I need to go out and read the section in the RFC a second time to verify the details. […]

One way to avoid tcpdump “packets dropped by kernel” messages

I have been knee deep this week debugging a rather complex DNS issue. I’ll do a full write up on that next week. While I was debugging the issue I needed to fire up tcpdump to watch the DNS queries from one of my authoritative servers to various servers on the Internet. What I noticed […]