Static NAT

With the increase of interconnections for communication and data sharing  IP address management is necessary. Network Address Translation (NAT) is one of the technologies playing a critical role in this operation. For many, Static NAT is favored, as it provides a specific benefit to networking environments that require a reliable, one-to-one IP mapping between local and public networks. 

What is Static NAT? 

Static Network Address Translation (Static NAT) will only support mapping one private IP address to one public IP address. E Static NAT is commonly called one-to-one NAT as this is a continuous internal-external address relational between the inside global and inside local. 

Ionic NAT: in Static NAT, an organization’s internal (private) IP address is used and automatically modified into an external (public) IP address where needed, ensuring enterprise networked computers running with Network Address Translation technology are connected to the internet as well. The idea is that inside devices can look like they are using a public IP, so they can be reached from external networks. Static NAT permits inward and outbound traffic, so people can start reaching inner assets (e.g.: servers or websites) through the public IP address mapped. 

How Does Static NAT Work? 

Static NAT is broken down into the following steps:  

1. When a device in the internal private network wants to talk with the world outside (e.g. accessing a website, or sending data to a server out there), its non-routable private IP must be translated into a publicly exposed IP that has been pre-configured in a NAT table on a router/firewall etc. This mapping is not dynamic so the same internal IP will always map back to the same external IP.
2. Static NAT supports bidirectional communication. Not only does the internal device have the option of initiating outbound communication to external networks, but external devices can also initiate inbound communication to the internal device through the same public IP address. This is essential for services that need to be accessible from the outside, such as web servers, mail servers, and remote access solutions.
3. Connection persistence: This one-to-one mapping provides external systems with a consistent public IP address when corresponding with the same internal device. This consistency is important for scenarios in which services rely on pre-configured static IP addresses as part of their security, authentication, or policy enforcement assets.

Example of Static NAT 

For example, consider the following small business that hosts a web server internally on 192.168.1.10 (private IP address) We have an external server that must be internet-facing and available for automation. Unfortunately, because private IP addresses are not routable on the internet, the company needs to allow a public IP address onto this server by way of Static NAT. 

The network administrator configures Static NAT so that they can map the internal IP 192.168.1.10, to public IP 203.0.113.10 at Router C. Let’s assume an external user is trying to access the web server — they will use the public IP address 203.0.113.10, and using NAT,  this address will be translated to internal IP address 192.168.1.10 so traffic can come to the server. 

The key here is that the server will also make outbound connections translated from the internal address to the public IP we provided, and it can talk to external services. 

Key Benefits of Static NAT 

1. Consistent Public Addressing: Static NAT ensures that an internal device is always mapped to the same public IP address. This is crucial in cases where you need a static public IP; like when you host a web server, an email server, or a VPN gateway. A Tmux + WireGuard server receives traffic from external clients or services that need to know its public IP address is available for all of these to access.

1. Bidirectional Traffic: One advantage of Static NAT is that this configuration supports both inbound and outbound traffic. This is needed for services that can be accessed from outside the network, such as Web Servers, FTP servers, or app servers.

1. Improved Security with Firewall Integration: Static NAT Combined with Firewalls and ACLs to Improve Security. Although Static NAT exposes internal devices to the outside world by mapping them as Public IP addresses, the admin can control what kind of traffic is valid to travel through, e.g. HTTP or HTTPS. Only that allowed traffic is passed through the firewall, so there is less area for attackers to attack.

1. Support for Legacy Systems: A few legacy systems or applications mandate the need for a static public IP address, for reasons related to licensing, authentication, or security. The systems behind this are assured of always having the same public IP (Static NAT), even when they reside in a private network.

Use Cases for Static NAT 

1. Hosting Public Services: Solutions with public services that are internet accessible — like a Web server email server, or DNS Server hosted internally — can get the benefit of Static NAT. Once it gets turned on, the server is given an IP that stays the same, so other users and systems can always connect to your service.
2. Remote Access: One common use for static NAT is to provide access through a firewall to a remote-access VPN gateway or an RDP (Remote Desktop Protocol) server, without requiring users on the Internet to know its real address. From the outside, it is possible to connect to a known public IP address to get to the internal resources again.
3. Application Licensing: In the enterprise space, some applications need to contact an external licensing server to validate their license based on a public IP address. In this sort of situation, without Static NAT, the internal system would have a “random” public IP address between each square bracket {START} and {END}, without access to a single public IP that is required by the licensing process.
4. Branch Office Connectivity: For organizations with many branch offices, Static NAT helps to keep secure and stable connections between various locations. For example, each branch office may have internal servers or applications that need to be accessed from other locations; Static NAT is a feature that would ensure the public IP addresses for these resources remain static.

Experienced eMazzanti professionals can help you with Static NAT and other digital solutions.