DNS&Bind 9.2.1 examples & Questions:
I'm implenting bind 9.2.1 and following along in O'Reilly's DNS&Bind 4th edition book. I'm having a problem making the jump from their examples to what I should be implementing.Could anyone compentent in this area review the questions below and offer answers or suggestions. I don't mind a "RTFM" answer, unles I have, and am still stumped.
Thanks in advance:
Q1) DNS&Bind stated that the first field after the SOA in the SOA record is the "primary master name server" for the zone/domain. Given this (and their example) I would expect the following, given a zone of myhost.com and a ns of ns1.myns.com:
myhost.com. IN SOA ns1.myns.com. hostmaster.myhost.com. ( ....)
What causes me confusion is I've seen files that look like this:
myhost.com. IN SOA myhost.com. hostmaster.myhost.com. (.....)
Q2) Reverse Mapping (address to name) files: Given a multi-homed enviroment, where many domains use the same IP, how/why/when would you implement a db.111.222.333.444 file?
Which domains would you do this for in a typical hosting environment where most of the domains are multi-homed and use the same ip?
Q3) I'v read and re-read the section on Negative TTL (last field in the SOA record). I simply can't understand how this is used, or a proper value to set it to. Does it behave differently in a secondary NS vs a primary NS? What is a good rule of thumb for this?
Q4) In DNS&Bind, they provide an example of movie.edu. After studing the example, I don't see any A records that actually offer an address for movie.edu. See abrievated example below and PLEASE comment.
movie.edu. IN SOA terminator.movie.edu. hostmaster@movie.edu. (....)
movie.edu. IN NS terminator.movie.edu.
movie.edu. IN NS wormhole.movie.edu.
localhost IN A 127.0.0.1
carrie IN A 111.222.333.444
home IN A 111.222.333.441
big IN CNAME carrie
Where/how does movie.edu get its address assigned?
I would expect an "A" record for movie.edu.
Template Example:
Not withstanding my obvious struggle and ignorance here, what follows is a template I "think" I'll use for my domains. Please offer any comments that
apply:
<Start File>
$TTL 1d
myhost.com. in SOA ns1.myns.com. hostmaster@myhost.com. (
yyyymmddhhmmss ; serial
1d ; Refresh
1h ; Retry (secondary NS?)
1w ; Expire
1d) ; Neg TTL cache
myhost.com. IN NS ns1.myns.com.
myhost.com. IN NS ns2.myns.com.
myhost.com IN A 111.222.333.441
www IN A 111.222.333.441
ftp IN A 111.222.333.441
IN MX 10 myhost.com ; <= Why is the first field blank?
<End File>
Bob