1. (a) A; (b) AAA; (c) PTR.
2. (a) Cache poisoning can occur. (b) Deploy DNSSEC.
3. (a) DNS Resolver and DNS Forwarder. (b) DNS Resolver.
4. (a) 53; (b) UDP.
5. Host Overrides.
6. DDNS and RFC 2136.
7. You are validating certificates; you are running pfSense on an embedded system that does not have a battery for the clock; you want the correct time stamp on logs.
8. ntpq.
9. (a) Agents; (b) network management station.
10. Agents are unable to communicate with the SNMP daemon.