Assignment 6.1
1. A DNS servers with preform recursive queries or an SQL server
2. An A (address) record points to a domain.
3. identifies the email servers for a domain
4. $ hostname example.com or $ dig example.com
5. etc man host.conf will tell you about the order option etc Is for static dns resolve etc the file for all your dns needs then edit:
/etc/resolv.conf
add the following: nameserver 192.168.1.254 nameserver 1.2.3.4 (Google)
6. Add the following line to the Options section in /etc/named.conf: allow-query { 137.44.0.0/24 };
7. A resolver will append several different domains to an unqualified Domain Name producing FQDNS that passes them one at a time. (Google)
8. Set up a DNS cache that defines the zone . (period) clause explicitly, rather than relying on the hint file. (www.sobell.com)
10. Setting the TTL to a small number prevents DNS caches from holding
DNS entries for very long. Small TTL values place a large load on the local
DNS server because every query about the domain is forwarded to the local server. (www.sobell.com)

Assignment 7.1
1. "hello" change and you have to edit the mail server file
2. 1. File: "df": which stores the body of the message. 2. File: "qf": which stores the headers and other information.
3. The dnl command, which stands for delete to new line, instructs the compiler to ignore anything on a line following the dnl: It is used to set off comments. (www.sobell.com)
4. # /usr/sbin/praliases | head -5postmaster: rootdaemon MORE? OR touch dd= C /sbin/var/etc/config.you (Google)
5. /etc/mail/access
6. A. HELO (Hello)
The client sends this command to the SMTP server to identify itself and initiate the SMTP conversation. The domain name or IP address of the SMTP client is usually sent as an argument together with the command (e.g. “HELO client.example.com”). If a domain name is used