If you’re managing a Cisco Meraki network, configuring Network Address Translation (NAT) is a common and crucial task. Whether you’re mapping a single public IP to a private IP (1:1 NAT) or sharing a single public IP among multiple internal hosts (1:Many NAT), the Meraki GUI makes the process intuitive and straightforward.
In this guide, we’ll walk you through how to implement 1:1 NAT and 1:Many NAT using the Meraki dashboard step-by-step.
What Is NAT and Why Use It?
Network Address Translation (NAT) allows you to map private IP addresses within your network to public IP addresses accessible from the outside world.
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1:1 NAT means one public IP corresponds to exactly one internal IP. This is useful when you want external users to reach a specific device via a dedicated public IP.
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1:Many NAT means multiple internal devices share a single public IP address, typically using different ports to differentiate connections (often referred to as Port Address Translation—PAT).
Cisco Meraki’s cloud-managed dashboard simplifies NAT configurations, saving you from complex CLI commands.
Prerequisites Before You Start
- Ensure you have admin rights to your Meraki Organization.
- Public IP addresses assigned by your ISP must be configured on the Meraki MX firewall.
- Identify the internal IP addresses for which you want to configure NAT.
- Understand your network topology and routing needs.
Step-by-Step: Configure 1:1 NAT (Static NAT)
1. Log into the Meraki Dashboard
Go to dashboard.meraki.com and log in with your credentials.
2. Navigate to Your Network
Select the network where you want to configure NAT from your list of managed networks.
3. Go to Security & SD-WAN > Firewall & Traffic Shaping
In the left menu, click Security & SD-WAN, then choose Firewall & Traffic Shaping.
4. Scroll to the 1:1 NAT Section
In the firewall rules page, scroll down to the 1:1 NAT section.
5. Add a 1:1 NAT Mapping
- Click Add a 1:1 NAT rule.
- Enter the Public IP address (the IP provided by your ISP).
- Enter the LAN IP address (the internal device’s static IP).
- Choose the required settings such as allowed traffic or protocol as needed.
6. Save Changes
Click Save to apply the changes.
Your device is now accessible from the Internet using the specified public IP, with all traffic translated to the chosen LAN IP.
Step-by-Step: Configure 1:Many NAT (Port Address Translation)
The 1:Many NAT configuration is typically already running on your Meraki MX by default, translating multiple internal hosts through the MX’s WAN IP. However, you may want to set up specific port forwarding rules or allow inbound access to multiple hosts.
1. Log into the Meraki Dashboard
Sign into the Meraki dashboard as before.
2. Select Your Network and Go to Security & SD-WAN > Firewall & Traffic Shaping
Navigate to the network and enter the Firewall & Traffic Shaping settings page.
3. Scroll to the Port Forwarding Section
Find the Port Forwarding or Inbound rules section.
4. Add a Port Forwarding Rule
- Click Add a port forwarding rule.
- Enter the Public port (the port on the WAN IP that users will connect to).
- Enter the LAN IP (the internal host that will receive the traffic).
- Enter the LAN port (the port on the device listening for the traffic).
- Choose the Protocol (TCP, UDP, or both).
5. Save Your Configuration
Click Save to activate the forwarding rule.
Repeat this step for multiple internal devices to share the same public IP but different ports, effectively achieving 1:Many NAT.
Tips for Better NAT Configuration on Meraki
- Use Static IPs inside your LAN to avoid IP conflicts with NAT rules.
- Regularly review your NAT mappings and firewall rules for security.
- Label your rules clearly in the dashboard to maintain ease of management.
- Keep your MX firmware up to date to benefit from security patches and new features.
Final Thoughts
Configuring NAT in the Meraki GUI not only offers transparency and control but also eases network management by eliminating the need for command-line configurations. Whether you are exposing an internal server to the internet with 1:1 NAT or allowing several devices to connect externally via 1:Many NAT, the Meraki dashboard streamlines the process.
By following the steps above, you’ll ensure your network is properly set up for efficient and secure external access. Happy networking!
Keywords: Cisco Meraki, 1:1 NAT, 1:Many NAT, Port Forwarding, NAT configuration, Meraki GUI, Meraki MX Firewall, Network Address Translation
