Summary

In this chapter we have examined the core NTP protocols and configuration information, as well as how to configure NTP clients and servers. Given that NTP is a central service that ensures data integrity, we've also examined the security implications of running an NTP service and how it may be protected with appropriate access control and authentication mechanisms.

Questions

1.	Why is there a need for production systems to be able to regularly synchronize their clocks? To ensure data consistency in enterprise applications To ensure that time is printed correctly to users To ensure that machines can independently estimate time To ensure that an external hardware clock is required for every system
2.	What is the purpose of NTP? To allow every system to have their own external hardware clock To allow time to be synchronized between all systems on a network by using multicast To prevent access to primary time servers by network clients To filter timestamps and prevent their dispersion at the router level
3.	What kind of approach allows one server on the network to be delegated the authority for timekeeping for all systems on that network? Peer-to-peer Star topology Net topology Master-slave
4.	What is the major new feature of NTP v3? It supports a method for servers to communicate with a set of peer servers to average offsets and achieve a more accurate estimation of current time. It supports native public-key cryptography. It supports packet filtering firewalls. It permits up to 1,024 secondary servers per primary server.
5.	What is the name of the Solaris NTP daemon?. ntp ntpd xntpd nntpd
6.	Where is the sample NTP server configuration file located? /etc/inet/ntp.server /etc/inet/ntp.server.sample /etc/inet/ntp.sample /etc/inet/ntp.conf.sample
7.	What is the name of the command to start the NTP daemon in debug mode? ntp -d ntpd -d xntpd -d nntpd -d
8.	What is the Leap Indicator? Flag that indicates a leap year at the end of the day. NTP v3. Determines whether the message is symmetric active, symmetric passive, client, server, broadcast, or an NTP control message. Level of accuracy for the message, with 1 being a primary server and 2-255 indicating secondary servers of decreasing accuracy.
9.	What is the Version Indicator? Flag that indicates a leap year at the end of the day. NTP v3. Determines whether the message is symmetric active, symmetric passive, client, server, broadcast, or an NTP control message. Level of accuracy for the message, with 1 being a primary server and 2-255 indicating secondary servers of decreasing accuracy.
10.	What is the Mode? Flag that indicates a leap year at the end of the day. NTP v3. Determines whether the message is symmetric active, symmetric passive, client, server, broadcast, or an NTP control message. Level of accuracy for the message, with 1 being a primary server and 2-255 indicating secondary servers of decreasing accuracy.
11.	What is the Stratum? Flag that indicates a leap year at the end of the day. NTP v3. Determines whether the message is symmetric active, symmetric passive, client, server, broadcast, or an NTP control message. Level of accuracy for the message, with 1 being a primary server and 2-255 indicating secondary servers of decreasing accuracy.
12.	What is the Poll Interval? Maximum time separating messages Local clock precision Delay anticipated between the primary and other sources Error estimate from the primary source
13.	What is the Precision? Maximum time separating messages Local clock precision Delay anticipated between the primary and other sources Error estimate from the primary source
14.	What is the Root Delay? Maximum time separating messages Local clock precision Delay anticipated between the primary and other sources Error estimate from the primary source
15.	What is the Root Dispersion? Maximum time separating messages Local clock precision Delay anticipated between the primary and other sources Error estimate from the primary source

Answers

1.	A. To ensure data consistency in enterprise applications, there is a need for production systems to be able to regularly synchronize their clocks.
2.	B. The purpose of NTP is to allow time to be synchronized between all systems on a network by using multicast.
3.	D. A master-slave approach allows one server on the network to be delegated the authority for timekeeping for all systems on that network.
4.	A. The major new feature of NTP v3 is a method for servers to communicate with a set of peer servers to average offsets and achieve a more accurate estimation of current time.
5.	C . The Solaris NTP daemon is xntpd.
6.	A. The sample NTP server configuration file is located in /etc/inet/ntp.server .
7.	C . The name of the command to start the NTP daemon in debug mode is xntpd -q.
8.	A. The Leap Indicator is the flag that indicates a leap year at the end of the day.
9.	B. The Version Number is NTP v3.
10.	C. The Mode determines whether the message is symmetric active, symmetric passive, client, server, broadcast, or an NTP control message.
11.	D. The Stratum is the level of accuracy for the message, with 1 being a primary server and 2-255 indicating secondary servers of decreasing accuracy.
12.	A. The Poll Interval is the maximum time separating messages.
13.	B. The Precision is the local clock precision.
14.	C. The Root Delay is the delay anticipated between the primary and other sources.
15.	D. The Root Dispersion is the error estimate from the primary source..