DNS Review
=========

Records:
 - A = name -> ip
 - CNAME = codename, alias, nickname for an A record
 - MX = mailserver (for A record)
 - PTR = pointer, ip -> name, reverse, in-addr.arpa
   + ip address backwards 65.199.38.144.in-addr.arpa
 - SOA = start of authority

What files? (/etc/bind)
 - named.conf.local (zone declarations)
   + specify (master/slave, who to transfer to/from, allow-query, filename)
 - db.something.something.com (zone definition)
   + serial numbers (incremented every time)
   + timers
   + restart bind after editing
 - named.conf.options (options for the bind server)
   + allow-query
   + allow-recursion (deny this for people outside our network, security risk!!!)

Dig syntax
 - dig @somemachine somethingtodigfor <recordtype>
   + dig @8.8.8.8 www.thegummibear.com MX
   + dig @localhost www.thegummibear.com A
   + dig @localhost -x 144.38.199.60 PTR

Log file?
 - /var/log/syslog
 - service bind9 status

What is recursion? Caching-lookup server, recursvie name-server
 - root -> TLD -> auth