What functionality does mGRE provide to the DMVPN technology?
- It allows the creation of dynamically allocated tunnels through a permanent tunnel source at the hub and dynamically allocated tunnel destinations at the spokes.
- It provides secure transport of private information over public networks, such as the Internet.
- It creates a distributed mapping database of public IP addresses for all VPN tunnel spokes.
- It is a Cisco software solution for building multiple VPNs in an easy, dynamic, and scalable manner.
Answers Explanation & Hints:
DMVPN is built on three protocols, NHRP, IPsec, and mGRE. NHRP is the distributed address mapping protocol for VPN tunnels. IPsec encrypts communications on VPN tunnels. The mGRE protocol allows the dynamic creation of multiple spoke tunnels from one permanent VPN hub.