I know since i discovered the DMVPN in 2004/5 this is a very intelligent combination of IPsec, GRE and NHRP. Many Thanks to the Guys at Cisco, Christoph, Frederick and all other. This week i discovered "opennhrp" on sourceforge. It took me a minute or two to have a VM with debian up and the …
DMVPN with Linux
Patrick Marc's Networks 