Site to Site VPN Connections shows disconnected if there are no running vm's

### problem

Site to Site VPN Connections shows disconnected if there are no running vm's

### versions

ACS 4.22

### The steps to reproduce the bug

Steps to reproduce the issue

1. Create a 3 vpc networks

vpc1 > 172.30.21.0/24
vpc2 > 172.30.22.0/24

2. Create a respective network tier in each vpc

vpc1-tier1 > 172.30.21.0/28
vpc2-tier1 > 172.30.22.0/28

3. Enable VPN for each vpc

Navigate to each vpc source nat ip and enable vpn

vpc1 > publicip address (source nat) > Enable vpn
vpc2 > publicip address (source nat) > Enable vpn

4. Create Customer Gateway for each each vpc

Navigate > Network > VPN Customer Gateway

Name (vpc1-gateway) > Gateway ( publicip address (source nat) > CIDR list (172.30.21.0/28 ) > IPsec preshared-key ( from step 3 for each vpc)
Name (vpc2-gateway) > Gateway ( publicip address (source nat) > CIDR list (172.30.21.0/28 ) > IPsec preshared-key ( from step 3 for each vpc)

5. Enable VPN Gateway

Home > Network > VPC > VPC-1 > VPN gateway (Enable)
Home > Network > VPC > VPC-2 > VPN gateway (Enable)

6. Create a vpn connections to

VPC1 ↔ VPC2 ( VPC1 (active , VPC2 (passive)))

cmk createVpnConnection s2svpngatewayid= <> s2scustomergatewayid=<> passive=true

cmk createVpnConnection s2svpngatewayid= <> s2scustomergatewayid=<> passive=false

7. Check all the vpn connections > All are in disconnected state

Workaorund

8. Deploy vm's in each vpc tier become vpn connections are connected

Only then the vpn connections are established

Please check the following commands and logs to troubleshoot ipsec related issues

root@r-86-VM:~# ipsec statusall
root@r-86-VM:~# ip xfrm state
root@r-86-VM:~# ip xfrm policy

root@r-86-VM:/etc/ipsec.d#cat ipsec.vpn-.conf
root@r-86-VM:/etc/ipsec.d#cat ipsec.vpn-.secrets
root@r-86-VM:/etc/ipsec.d#cat l2tp.conf

root@r-86-VM:~#cat /var/log/daemon.log

### What to do about it?

The site to site vpn tunnel should get established even if there are no vm's present in the initial deployment

IKE/IPsec negotiation happens VR-to-VR over the public IPs that negotiation doesn't inherently need a guest VM to exist.

Currently, the IKE initiation on the active side is contingent on some triggering event , that trigger generally comes from a config re-push tied to VM deployment (which touches routing/network state across the VRs),

実行中のVMなしでVPN接続のセットアップを再現し、その後、VMをデプロイした後の状態と比較します。まず、ルーターVM上で、一覧にある ipsec statusall、ip xfrm state、ip xfrm policy の出力、設定ファイル、および /var/log/daemon.log を確認します。ゲストVMを必要とせずに IKE/IPsec トンネルが確立されれば完了です。

索引モデルが issue の本文から書いたものです。