It happens at some point: The company begins to grow; and so they do the demands of digital resources and their associated security challenges. And when looking for the most appropriate solution to distribute digital resources; you quickly bump into the network segmentation.
Network segmentation basically consists in the subdivision of digital resources to connect more devices to your networks without compromising their overall performance.
In other words, network segmentation is a simple organizational method that pursues the fast redistribution of network resources to prevent work disruptions and the bottlenecks.
However, its simplicity also brings challenges whose solutions we need to know. Let’s delve into some basic concepts that rule digital security in segmented environments.
Criteria for Network Segmentation
Network segmentation applies when we want or need to:
- Reduce network traffic due to node overload.
- Improve the general traffic of the network.
- Control traffic through its containment within the sub-network.
However, its simplicity also brings challenges and solutions that we need to know. Let’s delve into some basic concepts that will help us clarify the all picture.
Essentials rules for Network Segmentation
Also, network segmentation starts like this:
- Divide the network into logical segments. They can be whether physical or virtual segments. To them, we assign predetermined network masks.
- Distribute the network resources to each segment (subnet). In turn, each segment redistributes resources to N stations or devices.
- Connect network segments using switches (Layer 2), bridges (Layers 2-3) or routers (Layer 3).
Communication criteria between sub-networks
Similarly, it’s necessary to follow this protocol to achieve communication between sub-networks:
- Each router must be configured so that its IP addressing table allows automatic connection between networks and sub-networks.
- IPv4 interfaces must be configured with the addresses of each respective networks and/or sub-networks.
- We use router interfaces as predetermined gateways to achieve communication between networks and sub-networks.
From this perspective, carrying network segmentation seems pretty simple. However, there are other considerations to be reviewed regarding programming and security issues. Let’s examine the security implications.
Security and network segmentation
As we can see, the concepts and principles to achieve network segmentation are rather simple. They obey to uncomplicated distribution; the assignment of network masks and sub-masks is arbitrary; and we can even outsource the service to avoid associated complications.
However, achieving comprehensive digital security for network segmentation does represent a challenge. The reason is simple: Although the network infrastructure has evolved to help us to improve the speed of service delivery; the security infrastructure does not keep the same pace.
In any case, it is possible to achieve security standards for network segmentation. It can provide the security equipment with the necessary bases to dynamically protect the infrastructure and network services.
Again, the essentials to achieve network segmentation also allow us to logically group our assets, resources and applications into sections to protect them under specific security protocols.
Security principles for network segmentation
These are the minimum security principles to frame the segmentation:
- Know your assets, users and network traffic.
- Protect incoming and outgoing communications.
- Control network traffic by users and assets.
- Establish denial policies for interconnections between networks and subnetwork segments.
The work plan is equally simple and logical: Concentrate on only one of these tasks in only one of the network segments at the same time; and start with the simplest aspects from inside towards the wider network.
Let’s see what each of them implies in order.
1. Know your assets, users and network traffic
Knowledge is power. In order to establish access controls for the correct information distribution and flow, you need to start from the knowledge of each one of the aspects that make part of your networks.
In other words, you have to know how, to what extent and who uses your network resources to be able to allocate relevant bandwidths; and authorize and limit each actor to move within those safe parameters.
2. Protect incoming and outgoing communications
Speed and security must be both part of your goals for network segmentation. Thus, network segmentation gives you an advantage to properly use your resources to shield your networks. However, protection should not only be limited to controlling access to each segment.
Security in network segmentation must also include the ability to manage and diligently remedy any detected threat.
3. Control network traffic by users and assets
Once you have inventoried and granted protection to each network segment you gain full visibility on the way the users navigate through them.
So, the next logical step is to frame your the data that go in and out from your networks and sub-networks within communication policies. This is achieved through high-level controls (granular access).
Such high-level controls go through a two-step filter: Detection and Preventive controls. These will help you to recognize and analyze unexpected traffic.
4. Establish denial policies for interconnections between networks and subnetwork segments
Finally, it is time to wrap up everything. Until step 3, all the actions to frame network segmentation leaded to build a base that allows controlled access. The last thing left then is to authorize such access.
Let’s picture it with a practical example: Even when you select and hire your employees and they follow a fixed schedule into your company’s facilities, not all of them are allowed to freely go to all their areas.
To accomplish this policy; you grant security keys limited to open just few doors and accesses for each one your employees. Now, imagine that one of your employees loses his or her access key, and another person manages to use it to get into your facilities.
Although your company’s security has been compromised, the key’s protocols limit the stranger only to few areas. Also, it includes a last line of defense: It isolates and restrains the stranger so that he or she can not get out from the area where he or she is. This analogy applies for your digital security.
Network segmentation limits and helps you neutralizing threats and disruptions. Same, it provides more tools and options to remedy them.
Final considerations in digital security for network segmentation
Of course, the broader your network’s scope is; the longer you will take to achieve your ideal network segmentation. In the same way, you will have to delimit them in logical sub-units.
Likewise, you must incorporate and implement specific security policies whose compliance you will have to give special emphasis.
Finally, innovations and technological proposals will continue to appear, and you will need to incorporate them to refresh and update the value of your business. Every one of them will demand you to review your configuration parameters and network segmentation.
Network segmentation implies knowing and incorporating essentials in digital security that wraps up in Julius Caesar’s premise: Divide and rule. At GB Advisors we provide the best digital security tools and expertise that help you achieve this goal. Contact us here.
