Google cloud gateway
https://cloud.google.com/compute/docs/vpn/advanced
https://cloud.google.com/files/CloudVPNGuide-UsingCloudVPNwithCiscoASA.pdf
heres a (final/working) config in case anyone else wants to do this:
===================
crypto ikev2 proposal gcp-ikev2-proposal-1
encryption aes-cbc-128 aes-cbc-192 aes-cbc-256
integrity sha1 sha256 sha384 sha512
group 2 5 14 15 16
!
crypto ikev2 policy gcp-ikev2-policy-1
match fvrf any
proposal gcp-ikev2-proposal-1
!
crypto ikev2 profile gcp-ikev2-profile-1
match identity remote address gcp.gcp.gcp.gcp 255.255.255.255
identity local address me.me.me.me
authentication remote pre-share key xxxxxxxxxxxx
authentication local pre-share key xxxxxxxxxxxx
lifetime 10800
!
crypto ipsec transform-set gcp-tset-1 esp-aes esp-sha-hmac
mode tunnel
!
crypto ipsec profile gcp-ipsec-profile-1
set transform-set gcp-tset-1
set pfs group14
set ikev2-profile gcp-ikev2-profile-1
!
interface Tunnel0
ip address 169.254.0.2 255.255.255.252
tunnel source me.me.me.me
tunnel mode ipsec ipv4
tunnel destination gcp.gcp.gcp.gcp
tunnel protection ipsec profile gcp-ipsec-profile-1
!
===================
And then configure BGP or maybe static routes as required.
After adding in the Tunnel0 interface config it just started working
straight away. So I guess my config was right all along, its just some
other aspect of IPSEC that wasnt happy with something missing… Yay
misleading debug output. :-/
Hope that helps someone else.
Tom