merlin-vpn-routing

This script creates VPN Policy Routing rules for the OpenVPN Client in AsusWRT Merlin firmware. It helps fetch IP addresses that belong to domain names and saves them into the router’s policy configuration. This allows selective VPN routing based on destination IPs.

🚨 Important: This version works only with firmware 386.3+. For older firmware, use release 2.07.

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🔧 What It Does

• Reads domain names from domains.txt
• Resolves them into IP addresses (with optional subnet expansion)
• Adds static entries from static.csv
• Generates routing rules for the selected OpenVPN client
• Saves rules to file (not NVRAM)
• Optionally restarts the VPN client

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📂 Files

• vpol.py — core logic
• client1.py, client2.py, ... — configurations for each VPN client
• domains.txt — list of domain names (one per line)
• static.csv — static entries in format: Description,Source IP,Destination IP,Iface

Example: domains.txt

domain1.com
#example.com       # commented out
domain2.com
@subnetdomain.com  # use @ to resolve subnets (/xx)

Example: static.csv

ADomain,0.0.0.0,194.200.22.87/26,VPN

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🛠️ Requirements (on router)

• Entware
• Python 3
• bind-tools or bind-dig:

  opkg install bind-tools

• whois utility:

  opkg install whois

• pip:

  opkg install python3-pip

• Python module pydig:

  pip install pydig

• Optionally: git to clone the repository

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🚀 Usage

1. Clone the repo:

   git clone https://github.com/loglux/merlin-vpn-routing.git
   cd merlin-vpn-routing

2. Edit your client config (client1.py, etc):

   • local: local IP or subnet (e.g. 192.168.0.10, 192.168.0.0/24, or 0.0.0.0)
   • name_length: max description length (default: 10)
   • client: OpenVPN client number (1–5)
   • conf_path: optional path to domains.txt and static.csv

3. Run the script:

   python3 client1.py

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📅 Auto-start with VPN

To run the script automatically on VPN (re)start:

1. Create or edit /jffs/scripts/openvpn-event:

   #!/bin/sh
   python3 /path_to_script/client1.py

2. Make it executable:

   chmod a+rx /jffs/scripts/openvpn-event

⚠️ Important: comment out rules.client_restart(client) to prevent restart loops.

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🔙 Compatibility Note (Pre-386.3 Firmware)

Old versions of AsusWRT Merlin used NVRAM for storing rules, with strict space limits. This script no longer supports that mode. To support legacy systems, use release 2.07.

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📄 References

• Policy-based Routing — AsusWRT Wiki
• User Scripts — AsusWRT Wiki

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🙋 Contributing

Pull requests are welcome! If you have improvements, ideas, or bug fixes, feel free to fork the repo and submit a PR.