Q: I am so confused. How does DNS work?
A: If you're asking this question, you probably should hold off on setting up your own DNS server until you've got a better understanding of how the whole thing works. That said, I have found a couple resources on the web that do a good job of explaining how DNS works.
1. http://www.howstuffworks.com/dns.htm - This is very elemenary, but a good start if you're really clueless.
2. http://www.zoneedit.com/doc/dns-basics.html - A descent diagram showing how it all works.
Back
to top
Q:
What Unix/Linux flavors will the djbdnsrocks.org installation
work on?
A:
While I certainly have not tested this installation on every
single Unix/Linux distribution out there, I'm failrly certain
that it's portable to just about any Unix/Linux OS. I have successully
tested the installation on Redhat, FreeBSD, Debian, Suse, Slackware
and BSDi. Djbdns is more or less platform independent. It should
work on just about any Unix or Linux distro with relatively
few problems or modifications.
Back
to top
Q:
How can I flush the cache on my caching nameserver?
A:
Restarting dnscache will automatically flush the cache:
svc
-t /service/int_dnscache (to flush the internal cache)
svc
-t /service/ext_dnscache (to flush the external cache)
or if just
have a single caching server:
svc
-t /service/dnscache
Back
to top
Q: I have setup tinydns according to this site and I now have a DNS server called "ns1.mydomain.com". However, I need to have an "ns2.mydomain.com" as well. How do I do this?
A: Firstly, you need to know the logic behind having an "ns2.mydomain" server in addition to the "ns1.mydomain.com" server. The answer is simple: Redundancy. The "ns2" server functions as a backup server if the "ns1" server should be slow to respond or out of service. The same logic applies to why you would have an "ns3", "ns4" and so on. The more redundancy you have the better. However, 2 DNS servers is usually the bare minimum you would want to have in order to reliably serve DNS information. As you can probably guess, you would probably want to the secondary DNS server to be on a different physical server than the primary. It doesn't do much good to have multiple DNS servers running on the same server because if that server goes down, the primary and all the backups are down and you're screwed. However, since you are often required to register 2 nameservers in order to have a registered DNS server and since a lot of people don't have a second server to put the redundant DNS server on, it is possible to run 2 or more instances of Tinydns on the same machine. To make this happen, all you need to do is go through the installation on Tinydns again but this time you will want to install it as "tinydns2" and assign it to a different IP address. In other words, you would have a new directory called "/etc/tinydns2" and this would fucntion as the location for the secondary server zone files. You would then hook that "tinydns2" into the daemontools service monitor by creating softlinks to it.
Back to top
Q: What is the purspose of having more than 1 DNS server? For example: ns1.mydomain.com, ns2., ns3., ns4. and so on. Do I need these?
A: Firstly, you need to know the logic behind having an "ns2.mydomain" server in addition to the "ns1.mydomain.com" server. The answer is simple: Redundancy. The "ns2" server functions as a backup server if the "ns1" server should be slow to respond or out of service. The same logic applies to why you would have an "ns3", "ns4" and so on. The more redundancy you have the better. However, 2 DNS servers is usually the bare minimum you would want to have in order to reliably serve DNS information.
Back to top
Q:
Does the djbdnsrocks installation of djbdns contain
any changes to the inner workings of djbdns that I should know
about?
A:
No. I didnt' tamper with the inner workings of djbdns at all.
The version of djbdns that is used on this site is exactly the
same version that Dan Bernstein makes available on his site.
Some of the directory names that are created for dnscache and
tinydns may differ slightly from those of other installation
guides, but that is 100% inconsequential. You can name the dnscache
and tinydns directories whatever you want, so long as they are
referenced in the corresponding /service links.
Back
to top
Q: When I try to login to Vegadns I get this error: Error: /var/www/vegadns/sessions is not writabale. What's up?
A: This is caused by incorrect permissions or ownership settings on the private Vegadns directory. This can be fixed by setting the correct permissions and ownership. In the commands below, substitute in the correct patch to the vegadns_private directory and also change the "apache" user to whatever user your Apache server is runnig as.
chown -R apache:apache /path/to/web/server/root/vegadns_private
chmod -R 770 /path/to/web/server/root/vegadns_private
Back to top
Got a question
that's not listed here? Just ask me.
