What network separation is: a complete guide to the Korean security rule that decides adoption

Network separation is a Korean security requirement that divides the internal network handling business operations from the internet, physically or logically, blocking both external access to business systems and any path by which internal data could leave.

Why the shortlist narrows here

The call never leaves the building.

Where network separation applies, outbound API calls are blocked. A solution offered only via cloud cannot even connect, however strong its performance. The shortlist therefore contracts sharply at this point. What can be adopted is decided by deployment model rather than technical evaluation.

This is a point overseas vendors often find hard to place. Unlike markets where even security-conscious organizations can negotiate permission for external communication, in Korea the negotiation frequently does not exist as an option. A proposal into this market therefore has to explain the deployment model before it presents performance material.

What network separation actually is: how it differs from a firewall

Firewall and network separation across three axes

First, the level of control differs. A firewall filters and permits communication within one network. Network separation divides the networks themselves so that communication does not arise in principle.

Second, the implementation differs. Physical separation places equipment and circuits apart. Logical separation divides the business zone from the internet zone using virtualisation. Which one is in use changes both the media transfer procedure and the installation process.

Third, the effect on adoption differs. In a firewall environment, negotiating permission for the necessary communication is possible. In a network-separated environment that negotiation frequently does not exist, leaving internal installation as the only option.

The two are not in opposition. Organizations under network separation run firewalls inside each network as well.

Five things to confirm during evaluation

Five confirmations in an adoption review

First, confirm that installation completes inside the air-gapped network. If the installer reaches an external repository for components, the work stops.

Second, confirm the media transfer procedure. Which media, and which approvals, are required to bring in installation files and models varies by organization.

Third, confirm the update path. Without deciding how models and software will be updated, improvement stalls after adoption.

Fourth, confirm the licence activation method. Anything requiring periodic authentication against an external server will not function under network separation.

Fifth, confirm that components for handling domestic document formats are included. Installations do complete only for the team to find they cannot open a Korean word processor file.

How to work in a network-separated environment

Run validation inside from the start

Validating performance externally and moving only production inside is risky. The documents used in validation differ in condition from real intake, and the resource conditions inside differ too.

Where possible, install candidate products temporarily inside and validate on real documents. Whether a product can accept that procedure is itself a criterion for judgment.

Put transfer procedures into the schedule

The common cause of schedule slippage on network-separated projects is procedure rather than technology. Approval to bring in installation files, personnel access, and approval to take results out each take time.

Without reflecting those steps in the initial schedule, the validation period fills with waiting for approvals rather than actual work.

Organise the audit requirements alongside

Network separation governs the boundary with the outside; control inside comes as a separate set of requirements. Who processed which document, when, and which values were corrected all have to exist as records.

Role-based access control, retained processing history, and separation of production from the review environment are the representative items. Organising them at the start avoids the rework of bolting them on later.

Frequently asked questions