In order to configure a LAN-to-LAN tunnel between a Cisco IOS? router and an Adaptive Security Appliance (ASA), these configurations are required on the ASA:
Configure the crypto ipsec command in Phase 2.
Configure the isakmp policy command.
Configure the nat 0 command and the access-list command in order to bypass NATting.
Configure the crypto-map command.
Configure the tunnel-group DefaultL2LGroup command with group information