vyos@Vyos# set vpn ipsec esp-group cisco proposal 1
vyos@Vyos# set vpn ipsec esp-group cisco proposal 1 encryption aes256
vyos@Vyos# set vpn ipsec esp-group cisco proposal 1 hash md5

vyos@Vyos# set vpn ipsec esp-group cisco pfs enable
vyos@Vyos# set vpn ipsec esp-group cisco lifetime 900
vyos@Vyos# set vpn ipsec esp-group cisco mode tunnel