Linux VPN, IPSEC, OpenSwan - Tip's, Tutorials and References

1. Introduction

In this post, I'm just gathering tips, tutorial and references.

2. References

• https://raymii.org/s/tutorials/IPSEC_L2TP_vpn_on_CentOS_-_Red_Hat_Enterprise_Linux_or_Scientific_-_Linux_6.html

TCP/IP, Iptables, firewall, nmap and related

1. Introduction

I'm just gathering references to well done posts, tutorials and documentation about TCP/IP, Iptables, firewall and related

2. References

2.1. References (tagged with major subject)

• http://www.tccamargo.com/linux/tutoriais/iptables.html (*** tutorial; doc)
• http://www.frozentux.net/iptables-tutorial/iptables-tutorial.html
• http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch14_:_Linux_Firewalls_Using_iptables#.UktRl-VmyqG (*** tutorial; doc) 
• http://www.centos.org/docs/5/html/Deployment_Guide-en-US/ch-iptables.html (tutorial; doc)
• http://www.vivaolinux.com.br/artigo/Analizando-os-logs-do-IPTables (log; --log-prefix)
• http://www.thegeekstuff.com/2012/08/iptables-log-packets/ (log; --log-prefix)
• http://www.cyberciti.biz/tips/force-iptables-to-log-messages-to-a-different-log-file.html (log; --log-prefix)
• http://nmap.org/bennieston-tutorial/ (tutorial)
• http://www.centos.org/docs/4/html/rhel-sg-en-4/ch-ports.html (-p <port-name>)
• http://upload.wikimedia.org/wikipedia/commons/3/37/Netfilter-packet-flow.svg (packet flow)
• http://www.karlrupp.net/en/computer/nat_tutorial (packet flow; nat)
• http://en.wikipedia.org/wiki/Network_Address_Translation (nat; snat; dnat; pnat; masquerading)