In this mode, you can configure the ISAKMP/IKE public key that a remote peer uses for RSA authentication during the tunnel establishment phase without the need for a digital certificate.
From Global Configuration mode, type ipsec key pubkey-chain rsa and either the IP address or fully qualified domain name of the remote peer, and press Enter.
host1(config)#ipsec key pubkey-chain rsa address 192.168.50.5 host1(config-peer-public-key)#? default Set a command to its default(s) do Run an exec mode command (alias command run) exit Exit from the current command mode help Describe the interactive help system key-string Enter key string log Configure logging settings macro Run a CLI macro no Negate a command or set its default(s) run Run an exec mode command (alias command do) sleep Make the Command Interface pause for a specified duration