References

http://www.cisco.com/en/US/netsol/ns590/networking_solutions_white_paper09186a008009d67f.shtml

http://www.cisco.com/en/US/netsol/ns589/networking_solutions_sub_sub_solution.html

http://www.cisco.com/en/US/products/ps6604/products_ios_protocol_group_home.html

http://www.cisco.com/en/US/netsol/ns588/networking_solutions_sub_sub_solution.html

http://www.cisco.com/en/US/products/ps6603/products_ios_protocol_group_home.html

http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_guide09186a00801b2407.html#wp1050700

http://www.cisco.com/en/US/netsol/ns585/networking_solutions_white_paper0900aecd801edd5f.shtml

http://www.cisco.com/en/US/products/ps6648/products_ios_protocol_option_home.html

http://www.cisco.com/en/US/products/ps6603/products_white_paper09186a00801ed506.shtml

http://www.rfc-editor.org/rfc/rfc4364.txt

http://www.vpnc.org/vpn-technologies.html

http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cg/hmp_c/part20/mpbbk4.htm

http://www.cisco.com/en/US/tech/tk436/tk428/technologies_configuration_example09186a0080093fcc.shtml

http://www.cisco.com/en/US/tech/tk436/tk428/technologies_configuration_example09186a00800a6c11.shtml

http://www.cisco.com/en/US/tech/tk436/tk428/tech_configuration_examples_list.html