DNS

From JhuAcmWiki

Jump to: navigation, search

1 Asking for new hostnames
2 Our DNS servers
3 Pie in the sky

[edit]

Asking for new hostnames

Use [this] .

[edit]

Our DNS servers

[edit]

Two servers

We are running maradns on one server, typhon.acm.jhu.edu. It runs Debian sarge, too. At one point during the winter, we had reliability problems; we have a script that restarts maradns every twenty minutes now. Because of gryphon, this is not a big deal; if someone asks for the DNS record during a few seconds of downtime, it'll just look to gryphon.

Regular old bind is being run on gryphon.acm.jhu.edu. It is set to slave typhon.acm.jhu.edu, so DNS updates need only be made on typhon. (This is "secondary DNS".)

This isn't actually true right now - Gryphon is temporarily down.

[edit]

Regular old records

You can find them in /etc/maradns: ACM records go in /etc/maradns/db.jhuacm.org, and other records go in /etc/maradns/master/. The file format should be fairly comprehensible if you know DNS.

You should check out /etc/maradns/mararc to see the general configuration ideas. It's a neat config format; it's actually fully-fledged Python code.

[edit]

SOA Records!

It is essential that you update the SOA record at the top of db.jhuacm.org. In the SOA record there is the date followed by "01". Update it to today's date whenever you make changes.

This should solve the problem with blaze.

/etc/maradns/bin/update-jhuacm.org does this automatically.

[edit]

jhuacm.org vs. acm.jhu.edu

These are the same domain name. You can see in /etc/maradns/mararc how we merge them.

[edit]

Historical note: Blaze used to be buggy

Blaze used to be slaving us and having a really difficult time with it. Now, both (1) it can slave us, and (2) it doesn't. So, now blaze.cs.jhu.edu is a DNS server that serves up working DNS to the whole world. Hooray!

Of course, that means we're responsible for our own DNS. Should we work out a slaving agreement with some other computing club, perhaps?

[edit]