When should this be used? Should I bring up a point to point connection?
Is there an easy software way to set up a VPN for traffic between other datacenters and AppNexus facilities.
At the moment AppNexus does not offer a hardware VPN solution. We are researching options. In the meantime, we suggest two free software solutions.
1. Openswan http://www.openswan.org/
Openswan is an open source implementation of IPsec for the Linux operating system and a code fork of the FreeS/WAN project. IPSEC, or Internet Protocol Security, uses strong cryptography to provide both authentication and encryption services. Authentication ensures that packets are from the right sender and have not been altered in transit. Encryption prevents unauthorized reading of packet contents. The IPSEC protocols were developed by the IETF (Internet Engineering Task Force)
More recent development:
OpenVPN was announced winner for "Best SSL VPN" in the 2007 Best of Open Software Awards by InfoWorld http://www.infoworld.com/bossies. It is an open source SSL VPN solution that accommodates a wide range of configurations, including remote access, site-to-site VPNs, Wi-Fi security, and enterprise-scale remote access solutions with load balancing, failover, and fine-grained access-controls. Starting with the fundamental premise that complexity is the enemy of security, OpenVPN offers a cost-effective, lightweight alternative to other VPN technologies that is well-targeted for the SME and enterprise markets.