A 10-Minute Guide for Using PPP to Connect Linux to the Internet
To drop a connection you just need to kill pppd. When it exits, it will hang up the line, if you've configured the modem as I've suggested.
On most distributions this will be as simple as:
# killall -HUP pppd
If you are lucky enough to have a semi-permanent connection to your ISP, i.e., one where you can stay connected for as long as you like, you may want to have your Linux automatically redial if the telephone call drops out for some reason. Here is a simple way of doing this that assumes you have configured your PPP link to be activated by root.
The first very important step is to add this line to your /etc/ppp/options file:
This line tells pppd not to go into the background after it has successfully connected. The next step is to add a line to your /etc/inittab file that looks like this:
pd:23:respawn:/usr/sbin/pppdPut this line down with the other lines that are similiar to it—the ones that run the login program.
This line simply tells the init program that it should automatically start the /usr/sbin/pppd program and that it should automatically restart it if it dies. Provided you have your modem configured to raise Data Carrier Detect and you have configured pppd as I have described, init will ensure the pppd program is always running and re-run it if it terminates.
A word of warning—this is simple, but provides no safeguards against problems that might cause the telephone call to be successfully made and then hang up. If you experience this problem, the init program will quite happily keep re-running the pppd program until you tell it to stop. You could run up quite a telephone bill if something nasty goes wrong.
This article describes a basic PPP configuration. There are many excellent documents that provide more detailed and comprehensive information on the subject. This article should be sufficient to get you connected to the Internet in a typical configuration. If you have any problems you cannot diagnose, I strongly recommend you read the PPP-HOWTO by Robert Hart at:
Robert has done an excellent job in rewriting the HOWTO, and it should be of assistance to you.
Practical Task Scheduling Deployment
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
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- Stunnel Security for Oracle
- The Firebird Project's Firebird Relational Database
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- SUSE LLC's SUSE Manager
- Managing Linux Using Puppet
- My +1 Sword of Productivity
- Non-Linux FOSS: Caffeine!
- Doing for User Space What We Did for Kernel Space
- SuperTuxKart 0.9.2 Released
- Google's SwiftShader Released
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide