Book Image

Designing and Implementing Linux Firewalls and QoS using netfilter, iproute2, NAT and l7-filter

By : Lucian Gheorghe
Book Image

Designing and Implementing Linux Firewalls and QoS using netfilter, iproute2, NAT and l7-filter

By: Lucian Gheorghe

Overview of this book

Firewalls are used to protect your network from the outside world. Using a Linux firewall, you can do a lot more than just filtering packets. This book shows you how to implement Linux firewalls and Quality of Service using practical examples from very small to very large networks. After giving us a background of network security, the book moves on to explain the basic technologies we will work with, namely netfilter, iproute2, NAT and l7-filter. These form the crux of building Linux firewalls and QOS. The later part of the book covers 5 real-world networks for which we design the security policies, build the firewall, setup the script, and verify our installation. Providing only necessary theoretical background, the book takes a practical approach, presenting case studies and plenty of illustrative examples.
Table of Contents (14 chapters)
Designing and Implementing Linux Firewalls and QoS using netfilter, iproute2, NAT, and L7-filter
Credits
About the Author
About the Reviewer
Preface
Index

Linux as SOHO Router


SOHO stands for Small Offices and Home Offices, and usually refers to situations where there exists just one computer at home to a few computers in a small office.

There is a very large offer of SOHO routers on the market nowadays from various manufacturers, but from what I've tested, most of them do the same basic things (NAT, DHCP, and some port filtering). They are less expensive than any computer, but if you have an old computer that you are about to throw away, you can easily install Linux on it and make it your own SOHO router having the advantage of higher flexibility at zero cost.

Usually, a SOHO router has a WAN port that is an Ethernet port where the provider connection must be plugged in. The Provider's CPE (Customer Premises Equipment) can be of any type (xDSL modem, wireless bridge, cable modem, fiber optic media converter) that can provide an Ethernet connection. SOHO routers usually have four to eight Ethernet ports for the LAN. This is basically a small...