Technical data

Network Server Services

This chapter describes key concepts for the following network server features:

• Network Time Protocol (NTP)

•Routing

• Remote client management (BOOTP/DHCP)

• File Transfer Protocol (FTP)

•SNMP

Things to Consider

In planning your TCP/IP Services for OpenVMS, consider the following:

• Will the system serve as a time server and at what stratum? Where does the

authoritative time come from?

• Do I need to remote boot any clients? Which kinds?

• Will the system serve as a router? What kind?

• Which file transfer method should I use: FTP or RCP? What are the security

needs, client types, and the purposes of the transfer?

• Will I need to service SNMP programs?

5.1 Network Time Protocol (NTP)

The Network Time Protocol (NTP) synchronizes time and coordinates time

distribution throughout a TCP/IP network. TCP/IP Services NTP software is an

implementation of the NTP Version 4 specification and maintains compatibility

withNTPVersions1,2,and3.

Time synchronization is important in client/server computing. For example,

systems that share common databases require coordinated transaction processing

and timestamping of instrumental data.

Synchronized timekeeping means that hosts with accurate system timestamps

send time quotes to each other. Hosts running NTP can be either a time server

or a time client, although they often are both a server and a client. NTP does

not attempt to synchronize clocks to each other. Rather, each server attempts to

synchronize to Coordinated Universal Time (UTC) using the best available source

and the best available transmission paths to that source. NTP expects that the

time being distributed from the root of the synchronization subnet is derived from

some external source of UTC (for example, a radio clock).

If your network is isolated and you cannot access other NTP servers on the

internet, you can designate one of your nodes as the reference clock to which all

other hosts will synchronize.

Running an NTP server is optional. If you do set up an NTP server, you must

decide whether it will be the authoritative server or whether you will get time

from another server.

Network Server Services 5–1