Which two actions resolve the issue?

Refer to the exhibit.

After applying IPsec, the engineer observed that the DMVPN tunnel went down, and both spoke-to-spoke and hub were not establishing.

Which two actions resolve the issue? (Choose two.)
A . Configure the crypto isakmp key cisco address 192.1.1.1 on R2 and R3
B. Configure the crypto isakmp key cisco address 0.0.0.0 on R2 and R3.
C. Change the mode from mode tunnel to mode transport on R3
D. Change the mode from mode transport to mode tunnel on R2.
E. Remove the crypto isakmp key cisco address 10.1.1.1 on R2 and R3

View Answer

Answer: A,D

Explanation:

*When using DMVPN with IPSec, it is unnecessary to use tunnel mode. Because DMVPN uses GRE which means that a new IP header is already added by GRE. The GRE encapsulation happens on the tunnel interface before the encryption process takes place.