GCP ipsec.conf

# ipsec.conf
conn gcp-to-aws
  keyexchange=ikev1
  authby=secret
  type=tunnel
  left=10.xxx.0.4           #Host internal ip address
  leftid=gcp 
  leftsubnet=10.xxx.0.0/9  #Host intranet      
  right=xx.xx.xx.xx         #Peer2 ip address
  rightid=aws 
  rightsubnet=10.xx.xx.xx/x #Peer2 accesible intranet
  ike=3des-md5-modp1024     #Phase 1 integrity check algos
  esp=aes128-sha1-modp1024  #Phase 2 Encryption algos
  ikelifetime=28800
  lifetime=3600
  dpddelay=30
  dpdtimeout=120
  dpdaction=restart
  auto=start