cd /etc/bind vi db.nas-admin.org
- 3 gets you to the most important line in the whole file
the serial #
every time you make an edit in a db file for bind you MUST update that line or the changes will not be picked up
remember the . at the end
the AXFR is the "zone transfer" to our servers that front for us.
Jan 28 08:30:17 fran named: zone transfer (AXFR) of "nas-admin.org" (IN) to
[188.8.131.52].54082 serial 2011012701
so...basically remember 3 things
1) always update the serial
2) cnames are "aliases" for other machines
3) always end the names in the right hand side with a . or else you will get something like this IP Addresses do not need a . at the end.
IF you forget you will get something like this: foo.nas-admin.org.nas-admin.org
if you really wanted foo.nas-admin.org there are 2 wasys to do it
1) just simply foo and it will automagically append .nas-admin.org
service bind restart (or reload)
tail -f /var/log/daemon.log
<ka6sox> DNS is a big TREE.
<ka6sox> the top levels (called TLD's) or Top Level Domains are housed in those servers (like 8-9 of them)
<ka6sox> they basically point to things like .org and .tw etc
<ka6sox> and .org is someplace else.
<ka6sox> and .org knows how to get to novaports
<ka6sox> and novaports (us) knows how to get to pulsar
<Jack87> got it
<ka6sox> so in this case the question gets asked 4X
<Jack87> hence... pulsar.novaports.org
<ka6sox> there are like 5 different main kinds of records
<ka6sox> NS or "nameservers"...these are the nameservers that give the answer to others...
<ka6sox> in our case we are using the nameservers @ osuosl.
<ka6sox> see them?
<ka6sox> okay below that are MX
<ka6sox> mx means "mail exchanger"
<ka6sox> we have 1
<Jack87> whats gabe?
<ka6sox> if we had several they would all be listed
<ka6sox> OLD long dead server...so this is cruft
<ka6sox> now if we had several the numbers like the 10 mean something
<ka6sox> a number of 10 would be prefered over a 20 server
<ka6sox> below that are the A records
<ka6sox> or Address records
<ka6sox> those point to "our" machines
<ka6sox> below that are the CNAMES or "common names"
<ka6sox> those are like www and other things...
<ka6sox> so blog and mentoring point to fiona
<ka6sox> but www points to fran
<ka6sox> there are a couple of special symbols...
<ka6sox> one is @
<ka6sox> that means just the domain name...aka nas-admin.rog
<ka6sox> er org.
<ka6sox> IP addresses do not need a . at the end
<ka6sox> you see ns1 and ns2 there?
<ka6sox> see anything different?
<Jack87> @ is pointing them to nas-admin.org
<Jack87> @ is pointing them to .nas-admin.org
<ka6sox> so when someone asks for who knows about nas-admin.org the 2 servers that do are ns1 and ns2
<ka6sox> but there is something else different about them.
<Jack87> not an A record?
<ka6sox> no . at the end
<ka6sox> therefore what happens....
<ka6sox> yes, correct..it appends .nas-admin.org
<ka6sox> there are a few more types...but only 1 is in common use
<ka6sox> and thats a PTR
<ka6sox> lets close this
<ka6sox> okay this is called an: in-addr.arpa file
<ka6sox> it contains a list of IP addresses and the names associated with that address
<ka6sox> its also known as the "reverse" lookup table.
<ka6sox> the "dotted quads" are written in reverse order here
<ka6sox> so the real ip addresses are: 140.211.169.x
<ka6sox> but the name is the reverse of that
<ka6sox> when someone says "whats this stupid server @ 184.108.40.206" and asks DNS for its "name" this file is consulted
<ka6sox> and its melo.openembedded.rog
<ka6sox> this is especially important for mail servers.