A network engineer is configuring DMVPN and entered the crypto isakmp key cisc0380739941 address 0.

The crypto isakmp key command is used to configure a preshared key for ISAKMP authentication between two peers. The address 0.0.0.0 indicates that the key is valid for any peer address. Therefore, the same command must be entered on hostB with the same password in order to establish the tunnel with hostA. Changing the protocol to ikev2, using a different password, or changing the password to the default will not solve the problem, as they will create a mismatch in the authentication parameters. References:

Dynamic Multipoint VPN Configuration Guide, Cisco IOS Release 15M&T, section “Prerequisites for Dynamic Multipoint VPN (DMVPN)”

DMVPN - Concepts & Configuration, section “DMVPN - What is it?”

DMVPN Hub as the CA Server for the DMVPN Network Configuration Example, section “Prerequisites”