Specifications

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14 Configuring and Managing
Network Services
Use this chapter to learn the commands to configure and
manage DHCP, DNS, Firewall, NAT, and VPN services.
Mac OS X Server network services add administrative and managerial capabilities to
basic networking protocols. This chapter describes the commands used to configure
and manage network services.
For more information, see Network Services Administration.
Managing Network Services
Mac OS X Server uses the xinetd process to manage many UNIX network services,
such as FTP, finger, and so on. xinetd listens for requests on specific TCP/IP sockets
and is a secure replacement for inetd. However, because xinetd does not handle RPC
services well, inetd and xinetd are included with Mac OS X.
xinetd does the same things as inetd, with the added security benefits of access
control based on source address, destination address, and time, and provides extensive
logging, efficient containment of denial-of-service attacks, and the ability to bind
services to specific interfaces.
The configuration files for xinetd provide a mapping of services to the executable that
should be run to service a request for a given service.
For example, if you enable FTP file sharing, the ftpd process is not started immediately.
Instead, the configuration file is updated to reflect that xinetd should listen for ftp
requests, and when it receives one, it should launch ftpd to service the request.
When the first ftp request comes in to the computer, xinetd receives the request and
then launches
ftpd to handle it. In this way, xinetd can keep the number of services
running on a computer lower by launching only those that are requested by a client.
inetd and xinetd have their own configuration files. inetd uses one file, inetd.conf,
to map a service to its executable. Standard services that inetd handles are listed in
the file.