113 lines
No EOL
3.3 KiB
Markdown
113 lines
No EOL
3.3 KiB
Markdown
# StrongSwan VPN Verification Guide
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This document helps verify the successful setup of a site-to-site IPsec VPN tunnel using StrongSwan. The environment is provisioned with Terraform and initialized with cloud-init. The VPN configuration uses IKEv2 with a pre-shared key (PSK) and automatically starts during system boot.
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---
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## Network Overview
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The VPN connects a cloud network with an on-premises network, enabling secure, encrypted traffic between them.
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| Host | IP Address | Subnet | Role |
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|------------------|--------------|----------------|------------------------|
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| appliance01 | 10.1.1.10 | 10.1.1.0/24 | Cloud VPN Appliance |
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| machine01cloud01 | 10.1.1.11 | 10.1.1.0/24 | Cloud Internal Machine |
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| machine01cloud02 | 10.2.1.11 | 10.2.1.0/24 | Cloud Internal Machine |
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| appliance02 | 192.168.1.10 | 192.168.1.0/24 | On-Prem VPN Appliance |
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---
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## Architecture
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This diagram illustrates the VPN tunnel between `appliance01` (cloud) and `appliance02` (on-prem), supporting encrypted traffic between the routed subnets.
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---
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## 1. Verify StrongSwan Service
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To confirm the IPsec service is running and properly configured, SSH into each VPN appliance using the appropriate public IP address:
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```bash
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ssh -i ~/.ssh/id_rsa debian@<appliance-public-ip>
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```
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Then run:
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```bash
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sudo ipsec statusall
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```
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Sample expected output:
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```
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Status of IKE charon daemon (strongSwan 5.x.x, Linux x.x.x):
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uptime: ...
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worker threads: ...
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Connections:
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net-net: 10.1.1.10...192.168.1.10 IKEv2, dpddelay=30s
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net-net: local: [10.1.1.10] uses pre-shared key authentication
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net-net: remote: [192.168.1.10] uses pre-shared key authentication
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net-net: child: 10.1.0.0/16 === 192.168.1.0/24 TUNNEL
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Security Associations (SAs):
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net-net[1]: ESTABLISHED ...
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```
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What to check:
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- The connection is listed as `ESTABLISHED`
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- Subnets listed under the child SA should match your intended VPN traffic (e.g., `10.1.0.0/16 === 192.168.1.0/24`)
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---
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## 2. Verify VPN Network Connectivity
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Ping between hosts to validate that routing is working through the VPN tunnel:
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### 💻 From appliance01 (cloud) to appliance02 (on-prem)
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```bash
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ping 192.168.1.10
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# ✅ Successful ping confirms VPN tunnel works
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```
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### 💻 From appliance02 (on-prem) to appliance01 (cloud)
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```bash
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ping 10.1.1.10
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# ✅ Confirms bidirectional connectivity
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```
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### 💻 From machine01 (cloud internal) to appliance02 (on-prem)
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```bash
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ping 192.168.1.10
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# ✅ Tests routing through VPN appliance (appliance01)
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```
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### 💻 From appliance02 (on-prem) to machine01 (cloud internal)
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```bash
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ping 10.1.1.11
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# ✅ Tests project-project routing via SNA transfer network
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```
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### 💻 From appliance02 (on-prem) to machine02 (cloud internal)
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```bash
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ping 10.1.2.11
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# ✅ Tests project-project routing via SNA transfer network
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```
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### ❌ From machine01 (cloud) to appliance02 (VPN-disconnected)
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If you remove the static route that directs 192.168.1.0/24 through appliance01:
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```bash
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ping 192.168.1.10
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# ❌ Should fail, indicating that VPN appliance is required for routing
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```
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All success cases confirm correct tunnel and routing setup.
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Failures (when expected) validate routing dependency on the VPN stack. |