11.1. Introduction to libnet

Designed by Mike Schiffman, libnet is a portable, open source, C-language library for creating and injecting network packets. libnet supports packet creation at all network levels with the TCP/IP network model, as demonstrated in Figure 11-1.

Figure 11-1. TCP/IP model and example of supported protocols

As of libnet version 1.1.2.1, you can create packets for the following protocols:

802.1q	FDDI	ICMP	IPSEC	Token Ring	DHCP
802.1x	ARP	IGMP	DNS	VRRP	BOOTP
802.2	TCP	IPv4	RIP	MPLS	GRE
802.2 SNAP	UDP	IPv6	RPC	NTP	BGP
802.3	CDP	ISL	STP	OSPF	Sebek
Ethernet

In addition, you can create other protocols within libnet due to its absolute control over packet data content.

11.1.1. Installing libnet

libnet is distributed in source code form. You can download the source code for the latest version of libnet from the project home page at http://www.packetfactory.net/projects/libnet/.

On Unix and Unix-like systems, installing libnet is straightforward:

tar zxvf libnet.tar.gz
cd libnet
./configure
make
make install (as root)