XINETD - Extended Internet Daemon
April 16, 2017
I was recently looking into ways to provide ssh access inside linux network namespaces and came across xinetd. So I decided to dig more into it. Noting it down here so that I can refer it back.
It’s basically a daemon that listens for network requests and services them by spawning more processes.
The master configuration for xinetd lives in
/etc/xinetd.conf. Each service managed
by xinetd has a configuration file in
Each network service is listed in
/etc/services that xinetd could potentially manage.
Let’s look at an example from one of the services in
/etc/xinetd.d/ to see how it works:
An echo service
This was a default service that was present on my RHEL6 box. There were lots of settings in this file which were basically commented out. Most of them are self explanatory, so I have omitted them for brevity.
echo service simply provides an echo service (duh). But what port does it listen to?
The port can be checked in
/etc/services file, search for echo in file, and on my machine
it had an entry that looked like this:
If you try to connect to this port; the connection will fail since the disabled flag is set to yes in the above configuration file.
Let’s enable the service by setting
disable = no in
In addition, you’d need to restart the xinetd service.
Now again, let’s try to connect to service.
You can use xinetd to run your own network service and have full control. I have some ideas which I’ll document if they work.