ASA(config)# object network vpnserver
ASA(config-network-object)# host 192.168.110.20
ASA(config-network-object)# nat (inside,outside) static 24.37.204.37 service udp 500 500

ciscoasa# show nat

ASA(config)# object network private_ip
ASA(config-network-object)# host 192.168.110.20
ASA(config-network-object)# object network public_ip
ASA(config-network-object)# host 24.37.204.37
ASA(config-network-object)# object service 500
ASA(config-service-object)# service udp source eq 500
ASA(config-service-object)# object service 500
ASA(config-service-object)# service udp source eq 500
ASA(config-service-object)# exit
ASA(config)# nat (inside,outside) source static 192.168.110.20 24.37.204.37 service udp 500