Linux - SecurityThis forum is for all security related questions.
Questions, tips, system compromises, firewalls, etc. are all included here.
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Introduction to Linux - A Hands on Guide
This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter.
For more advanced trainees it can be a desktop reference, and a collection of the base knowledge needed to proceed with system and network administration. This book contains many real life examples derived from the author's experience as a Linux system and network administrator, trainer and consultant. They hope these examples will help you to get a better understanding of the Linux system and that you feel encouraged to try out things on your own.
Click Here to receive this Complete Guide absolutely free.
I'm using IPTables to design a firewall system for a project I'm doing. I've the routing commands done, but I need to check if they are correct (my professor is gone away). Below are the list of actions I have been asked to implement. I have a diagram of the network here: student.dcu.ie/~collern2 and some info on the simple network. I have given a good attempt at completing this rules and my main problem is that I've no one to compare my answer with. Thanks very much.
2)For network clients with IPs 10.4.38.121 to 10.4.38.200, Internet connection is via the
proxy server 10.4.38.10: port 3128.
a. Direct Internet connection by these network clients, via eth0, is blocked by the
b. SNAT of the proxy’s IP to the public IP 126.96.36.199 is implemented by the
firewall to allow proxy server requests to the Internet.
3) To conserve IPv4 IPs, and to reduce the hackers target surface, the public IP, 188.8.131.52
is used for all services, i.e. DNS (including zone transfers) on port 53, email on port 25,
web on port 80 & 443 (http &https). Therefore, all incoming traffic for these services must
be directed to the appropriate servers on the 10.4.38.0 network, and all outgoing traffic to
the Internet must appear to come from the public IP 184.108.40.206.
The forum rules do not permit posting homework questions on the forum, so we aren't going to answer your questions directly. You do however have some syntax errors in a few of the answers and to do IP address ranges you need to use either netmasks (220.127.116.11/255.255.255.0) or CIDR notation (18.104.22.168/24). This is an awesome tools for helping to calculate CIDR notations. Here are also some of the more helpful guides: