Linux Training : About NAT

I created a humble little chapter that serves as an introduction to iptables today. Also corrected minor errors in the router chapter. Both chapters are available online (12 page pdf) for your review.

The goal is to provide students (that have knowledge about sniffing, tcp, ip, arp, icmp,...) a practical introduction to setting up a router, packet filter, nat, snat and dnat on Linux with iptables.

10. Routers
     10.1. terminology
          10.1.1. router or firewall
          10.1.2. packet forwarding
          10.1.3. packet filtering
          10.1.4. NAT (network address translation)
          10.1.5. PAT (port address translation)
          10.1.6. SNAT (source network address translation)
          10.1.7. masquerading
          10.1.8. port forwarding
     10.2. packet forwarding
          10.2.1. about packet forwarding
          10.2.2. /proc/sys/net/ipv4/ip_forward
          10.2.3. /etc/sysctl.conf
          10.2.4. Practice: packet forwarding
          10.2.5. Solution: packet forwarding
11. Iptables
     11.1. about iptables
     11.2. packet filtering
          11.2.1. about packet filtering
          11.2.2. filter table
          11.2.3. Changing default policy rules
          11.2.4. Allowing ssh over eth0
          11.2.5. Allowing access from a subnet
          11.2.6. iptables save
          11.2.7. scripting example
          11.2.8. Allowing ICMP(ping)
          11.2.9. Practice: packet filtering
     11.3. network address translation
          11.3.1. about NAT
          11.3.2. SNAT (Source NAT)
          11.3.3. SNAT example setup
          11.3.4. IP masquerading
          11.3.5. DNAT (Destination NAT)