This is a list of sources I found useful while writing my comprehensive guides on VPNs for Small Business Owners, Home Office Workers, and Split VPNs
Bibliography for VPN Articles
Admins eHow. (5 September 2011). http://www.adminsehow.com/2011/09/iptables-packet-traverse-map
Andreasson, Oskar. Iptables Tutorial 1.2.1. (n.d.). Anicas, Mitchell. (14 August 2015). How To List and Delete Iptables Firewall Rules. Web blog. Brown, Martin A. Guide to IP Layer Network Administration with Linux. Version 0.4.4. (26 April 2003). http://linux-ip.net Ellingwood, Justin. (20 August 2015). A Deep Dive into Iptables and Netfilter Architecture. Digital Ocean. Force Torrent Traffic through VPN Split Tunnel Debian 8 + Ubuntu 16.04. (n.d.). Web blog. Gheorghe, Lucian. Designing and Implementing Linux Firewalls with QoS Using Netfilter. (31 October 2006) Guillermo, Garron. (18 April 2012). iptables: Small manual and tutorial with some examples and tips. Web blog. Hubert, Bert; Graf, Thomas; and Maxwell; van Mook, Remco; van Oosterhout, Martijn; Schroeder, Paul B; Spaans, Jasper; and Larroy, Pedro. (n.d.). Linux Advanced Routing & Traffic Control HOWTO. http://lartc.org/howto/ iproute2. Wikipedia. (16 November 2017). Iptables. (2008). http://www.iptables.info/en/connection-state.html iptables - Target to route packet to specific interface? (29 December 2011). Web post. http://serverfault.com/questions/345111/iptables-target-to-route-packet-to-specific-interface IptablesHowTo. (13 December 2013). Web post. iptables(8) - Linux man page. (n.d.). die.net. Kerrisk, Michael. (15 September 2017). Linux Programmer's Manual. RNETLINK(7) [chapter]. http://man7.org/linux/man-pages/man7/rtnetlink.7.html Kirkland, Dustin. (2010). xenial (8) iptables.8.gz. Ubuntu manuals. http://manpages.ubuntu.com/manpages/xenial/man8/iptables.8.html Kirkland, Dustin. (2010). xenial (8) iptables-extensions.8.gz. Ubuntu manuals. http://manpages.ubuntu.com/manpages/xenial/man8/iptables-extensions.8.html Kuznetsov, Alexey. N. (14 April 1999). IP Command Reference Litvak, Michail. (2010). xenial(8) ip-rule.8.gz. Ubuntu manuals.http://manpages.ubuntu.com/manpages/xenial/man8/ip-rule.8.html Linuxtopia. (n.d.). Linux Packet Filtering and iptables. Chapter 10: Iptables matches. http://www.linuxtopia.org/Linux_Firewall_iptables/x2682.html Lowe, Scott. (29 May 2013). A Quick Introduction to Linux Policy Routing. Weblog. Marsh, Matthew G. (n.d.). IPROUTE2 Utility Suite Howto. http://www.policyrouting.org/iproute2-toc.html Marsh, Matthew G. (6 March 2001).Policy Routing Using Linux (Professional). http://www.policyrouting.org/PolicyRoutingBook/ONLINE/TOC.html Mortimer, Ian. rp_filter not working ?? (21 September 2000). Email. http://lists.NetFilter.org/pipermail/NetFilter/2000-September/005400.html Netfilter. (20 December 2017). Wikipedia. nftables. (10 December 2017). Wikipedia. Only allow certain outbound traffic on certain interfaces. (26 April 2011). Web post. http://unix.stackexchange.com/questions/12085/only-allow-certain-outbound-traffic-on-certain-interfaces OpenVPN Community Wiki and Tracker. OpenVPN 2.4 Man Page. Redirect Routing on Non-Default Interface. (12 December 2008). Web post. http://ubuntuforums.org/showthread.php?t=1008620 Russell, Rusty. (14 January 2002). Linux 2.4 NAT HOWTO. Web blog. http://www.NetFilter.org/documentation/HOWTO/NAT-HOWTO.html#toc5 Russell, Rusty. (29 July 2001). Linux Networking-concepts HOWTO. http://www.NetFilter.org/documentation/HOWTO//networking-concepts-HOWTO.html Setup routing and iptables for new VPN connection to redirect **only** ports 80 and 443. (n.d.). Web post. http://superuser.com/questions/354855/setup-routing-and-iptables-for-new-vpn-connection-to-redirect-only-ports-80 Simon. MAKING ALL NETWORK TRAFFIC FOR A LINUX USER USE A SPECIFIC NETWORK INTERFACE. (28 August 2011). http://www.niftiestsoftware.com/2011/08/28/making-all-network-traffic-for-a-linux-user-use-a-specific-network-interface Split tunnel routing a specific port over OpenVPN on Ubuntu Server 12.04. (11 June 2013). Web post. http://superuser.com/questions/606159/split-tunnel-routing-a-specific-port-over-openvpn-on-ubuntu-server-12-04 UFW. (31 March 2017). Ubuntu documentation. Wagner, Tyler J. Disabling Reverse-Path Filtering in Complex Networks. (13 July 2009). http://www.tolaris.com/2009/07/13/disabling-reverse-path-filtering-in-complex-networks zesty(8) nft.8.gz (10 October 2016). Ubuntu Man Pages. http://manpages.ubuntu.com/manpages/xenial/en/man8/nft.8.html