This is great to make sure that people are not signing in and leaving their connection open. Who knows who can come over and start using that already authenticated connection?
Linux / UNIX Automatically Log BASH / TCSH / SSH Users Out After a Period of Inactivity.
This is a great way to setup accounts so that you know that the password you provided will be sure to go.
chage -d 0 {user-name}
# chage -d 0 tom
Linux: Force Users To Change Their Passwords Upon First Login.
This scares me, Microsoft could really be jerks and make block out other Operating Systems, it is bad enough that you have to buy a copy of windows with every new computer even if you don’t want it.
If you run a program which can sometimes output information in cron that information normally gets dumped to your user’s mail file. That means you would need to sign into the server to check the mail file and see the results. A better way is to have the results emailed out to you. You can do this by making a simple entry as shown below:
Adding that one line will then cause all cron output to go to the email address of [email protected].
One of the problems you can sometimes face with a website is people mirroring your site or search bots excessively connecting to you. This is very easy to fix by limiting the number of connections an IP address is allowed to make.
To do this you just need to install the mod_limitipconn Apache module. If you are using Fedora or CentOS you can easily install this module through yum:
yum install mod_limitipconn
Once it is installed it is very easy to config. You need to add the following line to your httpd.conf file:
LoadModule limitipconn_module modules/mod_limitipconn.so
Then you just need to add in the settings for the module. I have included some samples below:
<IfModule mod_limitipconn.c>
<Location />
MaxConnPerIP 3
NoIPLimit image/*
NoIPLimit application/javascript
</Location>
<Location /phpmyadmin/*>
NoIPLimit *
</Location>
</IfModule>
The above settings consist of two parts, the location and then the settings for that location. What is really nice is you can say certain folders are allowed more connections then others. This is very important now that most browsers use multiple threads to download a single page. This means that for a normal person to connect and view your website the browser may establish multiple connections.
In the above example you will see that I set the location to “/” (which means the entire site), then I say there is a MaxConnPerIP of 3, so I only want a max of three connections at a time from a single IP. The next thing you will see is NoIPLimit image/* and NoIPLimit application/javascript. Without these two settings multiple thread browser have a lot of problems loading pages since they often open up a connection for each of these content types plus one for the regular text on the site. The other thing to keep in mind when doing this is that NoIPLimit is looking for a MIME type and not a path.
Now the other thing you may want to do is set section of the website where there will be no limit at all. This is done again by setting the location (the example I used was phpmyadmin) and then saying NoIPLimit on any file type.
