Running the Internet daemons

If a host is a server, it invokes the appropriate daemon to satisfy a client's requests. A TCP/IP server typically runs the inetd daemon, also known as the Internet super-server.

CAUTION:

Running inetd lets outside users try to connect to your machine and thus is a potential security issue if you don't configure it properly.

The inetd daemon listens for connections on some well-known ports, as defined in /etc/inetd.conf, in the TCP/IP network. On receiving a request, it runs the corresponding server daemon. For example, if a client requests a remote login by invoking rlogin, then inetd starts rlogind (remote login daemon) to satisfy the request. In most instances, responses to client requests are handled this way.

You use the super-server configuration file /etc/inetd.conf to specify the daemons that inetd can start.

Note: As shipped in the QNX Neutrino distribution, the file contains commented-out descriptions of all currently shipped QNX Neutrino TCP/IP daemons and some nonstandard pidin services. You need to edit inetd.conf and uncomment the descriptions of the ones you want to use.

When it starts, inetd reads its configuration information from this configuration file. It includes these commonly used daemons:

ftpd: File transfer.
rlogind: Remote login.
rshd: Remote shell.
telnetd: Remote terminal session.
tftpd: DARPA trivial file transfer.

Note:

Remember that you shouldn't manually start the daemon processes listed in this file; they expect to be started by inetd.
Running rshd or rlogind can open up your machine to the world. Use the /etc/hosts.equiv or ~/.rhosts files (or both) to identify trusted users, but be very careful.

You may also find other resident daemons that can run independently of inetd—see the Utilities Reference for descriptions:

bootpd: Internet boot protocol server.
dhcpd: Dynamic Host Configuration Protocol daemon.
mrouted: Distance-Vector Multicast Routing Protocol (DVMRP) daemon.
named: Internet domain name server
ntpd: Network Time Protocol daemon.
routed: RIP and RIPv2 routing protocol daemon
rwhod: System status database.
nfsd: NFS server.

These daemons listen on their own TCP ports and manage their own transactions. They usually start when the computer boots and then run continuously, although to conserve system resources, you can have inetd start bootpd only when a boot request arrives.