Apple Mac OS X Server (Administrator’s Guide) - Manual (Page 54)

54 Chapter 1
DHCP
DHCP helps you administer and distribute IP addresses dynamically to client computers from
your server. From a block of IP addresses that you define, your server locates an unused
address and “leases” it to client computers as needed. DHCP is especially useful when an
organization has more clients than IP addresses. IP addresses are assigned on an as-needed
basis, and when they are not needed they are available for use by other clients.
As you learned in “Search Policies” on page 48, you can automate the directory services setup
of Mac OS X clients using your DHCP server’s Option 95 support. This option lets client
computers learn about their directory settings from an LDAP server.
Chapter 11, “DHCP Service,” provides information about your server’s DHCP capabilities.
DNS
DNS service lets users connect to a network resource, such as a Web or file server, by
specifying a host name (such as server.apple.com) rather than an IP address (192.168.11.12).
DNS is a distributed database that maps IP addresses to domain names.
A server that provides DNS service keeps a list of names and the IP addresses associated with
the names. When a computer needs to find the IP address for a name, it sends a message to
the DNS server (also known as a name server). The name server looks up the IP address and
sends it back to the computer. If the name server doesn’t have the IP address locally, it sends
messages to other name servers on the Internet until the IP address is found.
You will use DNS if you use SMTP mail service or if you want to create subdomains within
your primary domain. You will also use DNS if you are hosting multiple Web sites. If you don’t
have an Internet service provider (ISP) who handles DNS for your network, you can set up a
DNS server on your Mac OS X Server.
You’ll find complete information about DNS in Chapter 14, “DNS Service.”
IP Firewall
IP firewall service protects your server and the content you store on it from intruders. It
provides a software firewall, scanning incoming IP packets and accepting or rejecting them
based on filters you define.
You can set up server-wide restrictions for packets from specific IP addresses. You can also
restrict access to individual services—such as Web, mail, and FTP—by defining filters for the
ports used by the services.
See Chapter 15, “Firewall Service,” for more information about this service.
SLP DA
Service Location Protocol (SLP) provides structure to the services available on a network and
gives users easy access to them.