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Demystifying VPN Concentrators: An IT Pro‘s Guide

If you manage network infrastructure for a medium or large enterprise, chances are you‘ve wondered about VPN concentrators. How exactly do they work? Why are they better than other VPN options? What benefits do they provide compared to consumer-grade tools?

As an experienced IT professional who has installed and managed countless concentrators, let me provide some insider guidance. I‘ll answer these key questions and more so you have all the details to make informed decisions for your environment.

VPN Concentrators Clearly Explained

A VPN concentrator is a hardware appliance that enables multiple, simultaneous VPN connections to a central corporate network. It provides encrypted tunnels and access controls so remote employees and branch offices can securely access internal resources.

The concentrator sits at the edge of the corporate network and routes encrypted traffic between remote devices and internal servers and applications. This protects data in transit over the public internet.

Based on IT expert testing, a single concentrator can handle 5000 to 10,000 concurrent VPN connections. This huge capacity makes it feasible to scale remote access across large organizations with thousands of workers.

Popular encryption protocols supported include:

  • IPSec – Creates encrypted tunnels between sites. The go-to for office-to-office connections.
  • SSL/TLS – Allows client remote access from any web browser or app. No VPN software required on user devices.
  • L2TP/IPSec – Enables remote machines to have internal IP addresses on the corporate network. Compatible with almost all devices.

Why Enterprises Choose Concentrators

IT professionals prefer concentrators over consumer VPNs for good reason – they solve pressing needs for enterprises while providing unmatched security, performance, and availability.

Centralized Management – All VPN connections and policies are configured through a single interface rather than a per-device basis. Radically simplifies administration.

Scalability – A single concentrator can handle an order of magnitude more connections than even premium consumer VPN services. Critical for large remote workforces.

Secure Access – Strict access controls let remote employees work securely while limiting exposure of corporate assets. Extends the network perimeter.

Network Integration – Concentrators operate seamlessly with existing firewalls, proxies, authentication systems, and other infrastructure. Consumer VPNs don‘t have this tight integration.

High Availability – Redundant concentrator configurations with automatic failover provide 99.999% uptime. Critical for always-on remote access.

Let‘s examine how concentrators stack up to alternatives like site-to-site VPNs and consumer VPNs.

Concentrators vs. Site-to-Site VPNs

Site-to-site VPNs connect entire office locations on a network level. Concentrators secure traffic on a per-device basis, ideal for individual remote workers outside the office.

Concentrators also provide finer-grained control over specific user and device access. This limits exposure compared to opening a site-wide tunnel.

Concentrators vs. Consumer VPNs

Even premium VPN services max out at a few thousand simultaneous connections – not enough to support large enterprises. They also lack critical visibility into encrypted traffic.

IT admins have granular control over concentrator connections, advanced monitoring capabilities, and integration with other security tools like firewalls and proxies.

Furthermore, concentrators provide an always-on secure network that persists across locations. Consumer VPNs must be reconfigured in each new place you connect from.

Sizing and Selecting the Right Concentrator

With remote work exploding, concentrate on finding a robust concentrator model to fit current needs with room for growth.

Here are key capacity metrics to consider:

Max connections<10001000 – 50005000+
Throughput<100 Mbps100-500 Mbps>500 Mbps
Starting price<$500$500-$5000$5000+

Leading enterprise concentrator vendors include Cisco, Palo Alto, Fortinet, and WatchGuard. Open source options like pfSense are also available for more customization.

Talk to vendor reps to match capacity, protocols, and features to your technical requirements. And budget for future growth – a concentrator expected to last 3-5 years should be sized 30-50% above current capacity needs.

Securely Connecting Remote Workers

Once you have the right concentrator hardware in place, focus on making the VPN experience seamless for end users.

Best practices include:

  • Installing VPN client software – Provide client software that configures connections automatically. This makes it invisible to remote workers.
  • Enforcing MFA – Require multi-factor authentication via solutions like RADIUS to boost security.
  • Segmenting access – Utilize microsegmentation and VLANs so breaches in one tunnel don‘t spread. Limit access to only necessary resources.
  • Monitoring usage – Track concentrator performance and activity to optimize and identify anomalies proactively.
  • Streamlining support – Provide self-help resources and dedicated help desk assistance for VPN issues to improve productivity.

Taking these steps will maximize the value concentrators provide while minimizing headaches for your IT team.

Final Thoughts

VPN concentrators deliver robust, enterprise-grade solutions for securing remote access at scale. While the price tag is higher than consumer options, the payoff in centralized control, security, and sheer capacity make concentrators an indispensable tool for virtually any large organization.

Hopefully this insider look demystifies what concentrators are and why they are the gold standard for managing thousands of remote connections. By following best practices around sizing, selection, and deployment, you can implement a solution that stands the test of time and growth.



Michael Reddy is a tech enthusiast, entertainment buff, and avid traveler who loves exploring Linux and sharing unique insights with readers.