vyos@Vyos# set vpn ipsec ike-group cisco proposal 1
vyos@Vyos# set vpn ipsec ike-group cisco proposal 1 encryption aes256
vyos@Vyos# set vpn ipsec ike-group cisco proposal 1 hash md5
vyos@Vyos# set vpn ipsec ike-group cisco proposal 1 dh-group 14
vyos@Vyos# set vpn ipsec ike-group cisco lifetime 900