正解:C,D
Explanation/Reference:
Explanation:
IPsec in DMVPN is Optional
required are mGRE and NHRP
DMVPN is not a protocol, it is the combination of the following technologies:
+ Multipoint GRE (mGRE)
+ Next-Hop Resolution Protocol (NHRP)
+ Dynamic Routing Protocol (EIGRP, RIP, OSPF, BGP...) (optional)
+ Dynamic IPsec encryption (optional)
+ Cisco Express Forwarding (CEF)
DMVPN combines multiple GRE (mGRE) Tunnels, IPSec encryption and NHRP (Next Hop Resolution Protocol) to perform its job and save the administrator the need to define multiple static crypto maps and dynamic discovery of tunnel endpoints.