Four Strategies for Securing Your Perimeter Network Inside-Out

By CIOReview | Wednesday, July 6, 2016

Your network perimeter is like a castle in medieval times, bolstered with soaring walls, lofty gates, and patrolled by knights in shiny armor. Even during the middle age, people realize the importance of harboring multiple structures of defense mechanisms to secure the interior—and the practice has made its way into the digital era where organizations around the world are taking reliance on technologies like mobility to secure their walls.

Perimeter security is often the first line of defense for any network, which raises the question about its capabilities and resilience against incoming threats. Because, for ensuring a robust architecture the first layer of defense in the network has to be capable enough to nullify potential threats to a certain limit. Given that the threats that organizations confront today may not be the ones they have to deal with tomorrow, enterprises are required to design an architecture that is flexible enough to meet the future needs. Listed below are four strategies for designing a reliable perimeter network security.

Fortify Your Network Like a Castle

In order to maintain the confidentiality, integrity, and availability of enterprise networks, enterprises now implement a strategy known as defense-in-depth. As mentioned earlier, the strategy is similar to building multiple structured walls around a medieval castle to guard against invasion from outside. Defense-in-depth is the concept of deploying multiple layers of security around your walls; so that, if one layer of defense is breached, another will be in place to prevent further contraventions. Moreover, Script Kiddies–the people who look for an easy kill by targeting vulnerable organizations–will always have one or two cards up their sleeve rather than a single method of attack. Therefore, a multi-layered defense becomes an integral part of perimeter networks to thwart such wide variety of attacks.

The first line of defense and the most effective type of defense against script kiddies is always the firewall of an organization. A potent firewall can ably manage both incoming and outgoing traffic; however, an organization cannot always depend on the firewall alone for fortifying the entire security perimeter. For an effective security plan, enterprises should incorporate firewalls, intrusion detection systems, well trained users, policies and procedures, switched networks, strong password and good physical security into its perimeter network architecture. In addition, cloud-based malware detection and DDoS mitigation services can help nullify threats and analyze traffic even before it approaches an enterprise’s network.

Lock it down with DMZ

Generally, DMZ or Demilitarized Zone is a piece of area which lies at the border between two or more nations where military activities or installations are strictly prohibited by signed treaties or agreements. Similarly in networking, the DMZ is a buffer zone that splits your “trusted” internal network from the often hostile territory of the “untrusted” Internet. The DMZ is like the courtyard that lies just behind the firewall but ahead of your internal or private network. Therefore, if an enterprise is under attack the hacker will have to negotiate the DMZ along with the firewall before entering an enterprise’s private chambers. Though they are shielded by a firewall, they are still vulnerable to threats as it is connected to the internet. But, the DMZ acts as an extra line of defense and prevents hacks from directly accessing your organizations internal LAN.

Furthermore, the DMZ usually has a separate network ID from the enterprise’s internal network, nonetheless; you can also create a DMZ within the same network ID of your internal network, via Virtual LAN (VLAN) tagging. This is a method of partitioning traffic that shares a common switch, by creating VLANs as described in IEEE standard 802.1q. This specification creates a standard way of tagging Ethernet frames with information about VLAN membership. Furthermore, by segmenting the DMZ into various sub-networks enterprises can effectively prevent further data breaches in case of any contingencies.

Nullify Threats via VLAN Segmentation

Network segmentation through VLANs help enterprises establish a group of isolated networks within their data center. If properly put together, VLAN segmentation can meticulously negate any sort of threats to the perimeter network. Moreover, access is strictly limited to the authorized users who only “see” the servers and other devices necessary for executing daily tasks.

Protocol separation is another advantage of VLAN segmentation where IT administrators can limit certain protocols to certain segments of the enterprise. Also, use of VLANs ensures secure as well as flexible user mobility. For example, a user assigned to a specific VLAN will always connect to that VLAN regardless of location.

Additionally, dynamic VLAN assignment strengthens perimeter network defense by verifying a user’s group membership through a RADIUS authentication server and a user directory. Dynamic assignment is a critical requirement in building manageable networks. Static definition of security tends to cause long-term maintenance problems and impedes mobility of end users. By tying security to authentication information, retrieved at the point of network access, secure networks can support quickly changing and moving user populations with minimum staffing costs.

Implement End-to-end Data Encryption

Securing enterprise networks remain a challenging issue for many organizations due to the sensitivity of data carried by the networks. Moreover, deploying wireless network solutions without proper security measures can be a risky affair. The obvious solution for securing an enterprise network is to fortify it with strong encryption.

It is not necessary that an enterprise’s enemy will always be an outsider. Enterprises can have enemies within their ranks too. Encryption can prevent the loss of sensitive data through accidental or intentional disclosure. It can prevent attacks from outside your network as well as from within. Recent trends indicate that enterprises are moving towards an end-to-end data encryption model, which eliminates any potential threat for exposure.

To put things into perspective, Tsion Gonen, Chief Strategy Officer, SafeNet, commented, “Recent research findings reveal some interesting contradictions between the perception and the reality of data security. What’s worrying is that so many organizations are still putting all of their eggs in one basket when it comes to data security. Perimeter security technologies are just one layer of protection, but too many companies rely on them as the foundation of their data security strategy when, in reality, the perimeter no longer exists.”