From local linux , I tried check vpn status.
Why detailedStatus not proceed ? Why status still "FIRST_HANDSHAKE" ?
Shared key and TargetIP was not wrong.
$ gcloud compute vpn-tunnels describe gvis-vpn-tunnel
And echo was here.
creationTimestamp: '2020-07-28T15:05:44.541-07:00'
description: ''
detailedStatus: Allocating resources. VPN tunnel will start soon.
id:'2892217179569987543'
ikeVersion: 2
kind: compute#vpnTunnel
:
region: https://www.googleapis.com/compute/v1/projects/[project-id]/regions/us-east1
:
sharedSecret: '*************'
:
status: FIRST_HANDSHAKE
targetVpnGateway: https://www.googleapis.com/compute/v1/projects/[project-id]/regions/us-east1/targetVpnGateways/gvis-vpn
UPDATE
Last week , I could connect vpn tunnel. From this monday, could not connect and I saw logging as follows:
2020-07-28T22:45:04.831987016Z initiating IKE_SA vpn_58.xxx.xxx.xxx[779] to 58.xxx.xxx.xxx
2020-07-28T22:45:04.758749637Z creating acquire job for policy with reqid {1}
2020-07-28T22:45:02.148478373Z sending packet: from 35.xxx.xxx.xxx[4500] to 58.xxx.xxx.xxx[4500] (80 bytes)
2020-07-28T22:45:02.148478373Z generating INFORMATIONAL request 2 [ N(AUTH_FAILED) ]
2020-07-28T22:45:02.148478373Z tried 1 shared key for '35.xxx.xxx.xxx' - '58.xxx.xxx.xxx', but MAC mismatched
2020-07-28T22:45:02.148478373Z parsed IKE_AUTH response 1 [ IDr AUTH N(ESP_TFC_PAD_N) N(NON_FIRST_FRAG) SA TSi TSr ]
2020-07-28T22:45:02.105535147Z received packet: from 58.xxx.xxx.xxx[4500] to 35.xxx.xxx.xxx[4500] (256 bytes)
2020-07-28T22:45:02.029020541Z sending packet: from 35.xxx.xxx.xxx[4500] to 58.xxx.xxx.xxx[4500] (336 bytes)
2020-07-28T22:45:02.029020541Z generating IKE_AUTH request 1 [ IDi AUTH SA TSi TSr N(EAP_ONLY) ]
2020-07-28T22:45:02.029020541Z establishing CHILD_SA vpn_58.xxx.xxx.xxx{1}
2020-07-28T22:45:02.029020541Z authentication of '35.xxx.xxx.xxx' (myself) with pre-shared key
2020-07-28T22:45:02.029020541Z remote host is behind NAT
2020-07-28T22:45:02.029020541Z parsed IKE_SA_INIT response 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) ]
2020-07-28T22:45:01.933846400Z received packet: from 58.xxx.xxx.xxx[500] to 35.xxx.xxx.xxx[500] (464 bytes)
2020-07-28T22:45:01.819625244Z sending packet: from 35.xxx.xxx.xxx[500] to 58.xxx.xxx.xxx[500] (892 bytes)
2020-07-28T22:45:01.819625244Z generating IKE_SA_INIT request 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) N(FRAG_SUP) N(HASH_ALG) ]
Pre-shared key is same since December 2019. Everyday, When I want to connect , made vpn-tunnel like this,
gcloud compute vpn-tunnels create [my-vpn-tunnel] \
--peer-address 58.xxx.xxx.xxx \
--ike-version 2 \
--shared-secret [Pre-shared key] \
--local-traffic-selector=192.xxx.100.0/24 \
--remote-traffic-selector=172.xx.xx.0/24,192.xxx.10.0/24 \
--target-vpn-gateway [my-vpn] \
--region us-east1 \
--project [project-id]
And When I disconnect, delete vpn-tunnel like this,
gcloud compute vpn-tunnels delete [my-vpn-tunnel] --region=us-east1
I've always use gcloud on my linux shell script.
Because your problem resolved on its own we can only guess what caused this issue before.
As I wrote in the comments, it's better to follow troubleshooting guide and start from Cloud VPN logs.
Message Authentication Codes (MACs) are computed based on the pre shared key and the message and if pre shared keys do not match, corresponding MACs will not match as well. Meanwhile, it doesn't look like your case because you claim that "pre-shared key is same since December 2019".
Because you use NAT, I'd recommend you to have a look at the troubleshooting guide section On-premises gateways behind NAT:
more details you can find in this section:
It's possible that this issue could be related to your on-premises router, but it's hard to say without any logs.
In addition, next time you can check if this issue on the Google's side at the Google Cloud Status Dashboard and file an issue report at the Google Issue Tracker.