Howto: configure xinetd service under Linux or UNIX systems
Q. How do I configure xinetd under Fedora Core Linux?
A. xinetd, the eXtended InterNET Daemon, is an open-source daemon which runs on many Linux and Unix systems and manages Internet-based connectivity. It offers a more secure extension to or version of inetd, the Internet daemon.
xinetd performs the same function as inetd: it starts programs that provide Internet services. Instead of having such servers started at system initialization time, and be dormant until a connection request arrives, xinetd is he only daemon process started and it listens on all service ports for the services listed in its configuration file. When a request comes in, xinetd starts the appropriate server. Because of the way it operates, xinetd (as well as inetd) is also referred to as a super-server.
Task: xinetd Configuration files location
Following are important configuration files for xinetd:
- /etc/xinetd.conf - The global xinetd configuration file.
- /etc/xinetd.d/ directory - The directory containing all service-specific files such as ftp
Task: Understanding default configuration file
You can view default configuration file with less or cat command:
# less /etc/xinetd.confOR# cat /etc/xinetd.confOutput:
# Simple configuration file for xinetd
#
# Some defaults, and include /etc/xinetd.d/
defaults
{
instances = 60
log_type = SYSLOG authpriv
log_on_success = HOST PID
log_on_failure = HOST
cps = 25 30
}
includedir /etc/xinetd.d
Where,
- instances = 60 : Determines the number of servers that can be simultaneously active for a service. So 60 is the maximum number of requests xinetd can handle at once.
- log_type = SYSLOG authpriv: Determines where the service log output is sent. You can send it to SYSLOG at the specified facility (authpriv will send log to /var/log/secure file).
- log_on_success = HOST PID: Force xinetd to log if the connection is successful. It will log HOST name and Process ID to /var/log/secure file.
- log_on_failure = HOST: Force xinetd to log if there is a connection dropped or if the connection is not allowed to /var/log/secure file
- cps = 25 30: Limits the rate of incoming connections. Takes two arguments. The first argument is the number of connections per second to handle. If the rate of incoming connections is higher than this, the service will be temporarily disabled. The second argument is the number of seconds to wait efore re-enabling the service after it has been disabled. The default for this setting is 50 incoming connections and the interval is 10 seconds. This is good to avoid DOS attack against your service.
- includedir /etc/xinetd.d: Read other service specific configuration file this directory.
Task: How to create my own service called foo
Here is sample config file for service called foo located at /etc/xinetd.d/foo
# vi /etc/xinetd.d/foo
And append following text:
service login
{
socket_type = stream
protocol = tcp
wait = no
user = root
server = /usr/sbin/foo
instances = 20
}
Where,
- socket_type: Sets the network socket type to stream.
- protocol: Sets the protocol type to TCP
- wait: You can set the value to yes or no only. It Defines whether the service is single-threaded (if set to yes) or multi-threaded (if set to no).
- user: User who will run foo server
Task: Stop or restart xinetd
To restart xinetd service type the command:
# /etc/init.d/xinetd restart
To stop xinetd service type the command:
# /etc/init.d/xinetd stop
To stop xinetd service type the command:
# /etc/init.d/xinetd start
Task: Verify that xinetd is running
Type the following command to verify xinetd service is running or NOT:
# /etc/init.d/xinetd statusOutput:
xinetd (pid 6059) is running...
Further readings
- Read man pages of xinetd.conf and xinetd for more information.
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Related Other Helpful FAQs:
- How do I verify that service is turned on in xinetd under Fedora or Red Hat Linux?
- How To Tell If Your Linux Server Uses xinetd OR inetd sever
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Discussion on This FAQ
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Tags: cat command, configuration file, fedora core, internet daemon, unix systems, xinetd
September 7th, 2007 at 8:57 am
how to configure eternal disk using USB on sgi-irix and sun-solaris? Thanks.
December 25th, 2007 at 7:32 am
Hi,
Its very good. I was able to up and run at the first try itself. Thanks.
with regards,
December 28th, 2007 at 3:54 pm
I am curious: WHAT does “xinetd.d” mean, or stand for? How did it get that name?
December 28th, 2007 at 4:15 pm
xinetd => eXtended InterNET Daemon
.d => Directory with all configuration file
February 26th, 2008 at 1:18 pm
Very good info, am impressed!
May 12th, 2008 at 7:32 am
Hi,
Could you tell me if there is any command to modify xinetd configuration instead of manually editing the xinetd.conf file.
Thanks in advance,
Sudhir
June 23rd, 2008 (2 weeks ago) at 6:56 pm
Hi,
I am wondering how to start xinetd at system reboot?
thanks in advance!
-harjit
June 23rd, 2008 (2 weeks ago) at 7:15 pm
Harjit,
Under Debian / Ubuntu Linux, use sys-v tools.
Under RHEL / Fedora / CentOS Linux use chkconfig / ntsysv
HTH.