In May 2023, Barracuda Networks disclosed that a zero-day vulnerability in its VPN appliances had been actively exploited since October 2022 — giving threat actors seven months of undetected access to customer networks. CISA issued an emergency directive. The patch wasn't enough; Barracuda told customers to physically replace compromised hardware. That's the reality of VPN security today: having a VPN isn't the same as being protected by one.
If you're searching for VPN best practices, you're probably already past the "do I need one?" stage. Good. This post is for people who want to configure, deploy, and maintain VPNs correctly — whether you're protecting a 10-person office or a distributed enterprise. I'll walk you through what actually matters, what most organizations get wrong, and how a VPN fits into a broader security posture that includes zero trust, multi-factor authentication, and ongoing security awareness training.
Why Most VPN Deployments Fail Before They Start
I've audited dozens of VPN configurations over the years. The pattern is almost always the same: the organization bought or deployed a VPN solution, configured it with default settings, handed out credentials, and moved on. No logging. No segmentation. No kill switch policy. No review cycle.
The 2023 Verizon Data Breach Investigations Report found that 74% of all breaches involved the human element — including credential theft, social engineering, and misuse. A VPN doesn't fix any of that if the credentials protecting it are weak, reused, or phished. The VPN is only as strong as the policies wrapped around it.
Here's the uncomfortable truth: a poorly configured VPN can be worse than no VPN at all. It creates a false sense of security. Employees think they're protected. IT thinks the perimeter is sealed. Meanwhile, a threat actor with stolen VPN credentials has full network access — and nobody's watching.
VPN Best Practices That Actually Reduce Risk
Let me break this down into the practices I recommend to every organization I work with. These aren't theoretical. They're drawn from real incidents, real audits, and real failures I've seen firsthand.
1. Enforce Multi-Factor Authentication — No Exceptions
If your VPN only requires a username and password, you don't have a secure VPN. You have a login form connected to your internal network. The Colonial Pipeline ransomware attack in 2021 was traced to a single compromised VPN credential that lacked multi-factor authentication. That one credential led to a $4.4 million ransom payment and fuel shortages across the U.S. East Coast.
Every VPN connection must require MFA. Use hardware tokens or authenticator apps — not SMS-based codes, which are vulnerable to SIM swapping. This is non-negotiable in 2023.
2. Use Split Tunneling Deliberately — or Not at All
Split tunneling lets users route some traffic through the VPN and send the rest directly to the internet. It reduces bandwidth load on your VPN concentrator. It also creates a potential backdoor if a user's device is compromised.
For high-security environments, I recommend full tunnel configurations. If you must use split tunneling for performance, restrict it with granular policies. Only route non-sensitive, explicitly approved traffic outside the tunnel. Log everything. Revisit the policy quarterly.
3. Deploy Always-On VPN with a Kill Switch
Your employees will forget to connect. They'll work from coffee shops, airports, hotel Wi-Fi — all environments where an unencrypted connection is an open invitation for credential theft and data interception.
Always-on VPN configurations ensure the connection activates automatically when the device detects an untrusted network. Pair this with a kill switch that blocks all internet traffic if the VPN connection drops. Without a kill switch, a momentary disconnection can expose traffic in cleartext.
4. Segment VPN Access by Role
Not every employee needs access to every network resource. A marketing coordinator doesn't need access to your database servers. An external contractor doesn't need access to your HR systems.
Implement role-based access control (RBAC) within your VPN policies. Map user groups to specific network segments. This limits lateral movement if an account is compromised — which is a core principle of zero trust architecture.
5. Patch VPN Appliances Immediately — Not "Soon"
The Barracuda incident I mentioned wasn't an outlier. In 2023 alone, critical vulnerabilities were disclosed in Fortinet, Cisco, and Citrix VPN products. CISA's Known Exploited Vulnerabilities Catalog tracks dozens of VPN-related flaws that are actively being used by threat actors.
Patch cycles measured in weeks are too slow for VPN infrastructure. When a CVE drops for your VPN appliance, treat it as a fire drill. Have a tested process for emergency patching or mitigation. If you can't patch within 48 hours, consider taking the appliance offline and activating a backup access method.
6. Log and Monitor VPN Connections in Real Time
If you aren't logging VPN connections — source IP, timestamp, duration, user identity, bytes transferred — you're flying blind. A threat actor who compromises a VPN credential will often log in from an unusual geolocation, at unusual hours, or access resources the legitimate user never touches.
Feed your VPN logs into a SIEM or at minimum a centralized logging platform. Set alerts for impossible travel (logins from two distant locations within minutes), connections from known-malicious IP ranges, and access to sensitive resources by users who don't normally touch them.
7. Rotate and Audit Credentials Regularly
VPN credentials get stale. Employees leave. Contractors finish projects. Service accounts accumulate. Every orphaned credential is a potential entry point.
Audit your VPN user list quarterly at minimum. Disable accounts the day an employee departs — not the following Monday. Use unique, complex passwords or certificate-based authentication. If you're still using shared VPN credentials for any purpose, stop today.
What Are VPN Best Practices for Remote Workers?
For organizations with remote or hybrid teams, VPN best practices extend beyond the server configuration. Here's the condensed guidance I give to every remote workforce:
- Always connect to the VPN before accessing any company resource — email, cloud apps, file shares, everything.
- Never use public Wi-Fi without the VPN active. If the VPN fails, disconnect from the network entirely.
- Keep VPN client software updated. Outdated clients can have vulnerabilities just like outdated servers.
- Report any connection anomalies to IT immediately — unexpected disconnections, certificate warnings, or login failures could indicate a man-in-the-middle attack.
- Don't install VPN profiles from untrusted sources. Social engineering attacks sometimes trick users into connecting to attacker-controlled VPN servers.
This kind of guidance doesn't stick from a single email. It requires ongoing reinforcement. That's where structured cybersecurity awareness training makes a measurable difference — giving your team the context to understand why these rules exist, not just that they exist.
VPNs and Zero Trust: Complement, Don't Compete
There's a narrative in the industry that VPNs are dead and zero trust replaces them. That's an oversimplification. For most organizations in 2023, VPNs remain a critical layer — but they shouldn't be your only layer.
Zero trust means verifying every access request, regardless of where it originates. A VPN gives you an encrypted tunnel. Zero trust gives you continuous verification inside that tunnel. The best security posture uses both.
NIST Special Publication 800-207 defines the Zero Trust Architecture framework. If you're still relying on VPN access alone as your trust boundary, read it. The shift toward identity-aware proxies, microsegmentation, and continuous authentication doesn't eliminate VPNs — it makes them one checkpoint among many.
The Phishing Problem Your VPN Can't Solve
Here's what keeps me up at night: a perfectly configured VPN with MFA, logging, segmentation, and always-on policies — defeated by a phishing email that tricks an employee into entering their credentials on a fake login page.
The FBI's 2022 Internet Crime Report documented over 300,000 phishing complaints — the most of any crime type, for the third year running. Phishing remains the number one vector for credential theft. And once an attacker has a valid credential and MFA token (through real-time phishing proxies like EvilGinx), your VPN is an open door.
This is why VPN best practices must include anti-phishing measures. Technical controls like FIDO2 hardware keys for MFA help enormously. But you also need people who can recognize a phishing simulation — and a real attack — before they hand over the keys.
I recommend enrolling your team in dedicated phishing awareness training for organizations that includes simulated phishing campaigns, because the gap between "knowing phishing exists" and "spotting a well-crafted phishing email under time pressure" is enormous.
The $4.88M Lesson Most Organizations Learn Too Late
IBM's 2023 Cost of a Data Breach Report puts the global average cost of a data breach at $4.45 million. Breaches involving remote work — where VPNs are the primary security control — cost significantly more and took longer to identify.
The organizations that fared best shared common traits: they had tested incident response plans, they used encryption extensively, they deployed AI-driven security tools, and — critically — they invested in security awareness training. The cost difference between high and low security maturity was measured in millions of dollars.
Your VPN is infrastructure. Your configuration is policy. But your people are the variable that determines whether those investments pay off or collapse under a single well-crafted social engineering attack.
Your VPN Best Practices Checklist for 2023
Save this. Print it. Tape it to your monitor. Share it with your IT team:
- MFA on every VPN connection — hardware tokens preferred
- Always-on VPN with kill switch for all remote devices
- Role-based access control with network segmentation
- Full tunnel by default; split tunnel only with documented justification
- Real-time logging with SIEM integration and anomaly alerts
- Emergency patching process for VPN appliance CVEs
- Quarterly credential audits with immediate offboarding enforcement
- Certificate-based authentication where feasible
- Ongoing phishing simulations and security awareness training
- Annual review of VPN architecture against NIST zero trust guidelines
A VPN is a tool, not a strategy. The organizations that treat it as one component of a layered defense — combining strong configuration, continuous monitoring, zero trust principles, and trained humans — are the ones that avoid becoming the next case study. The ones that treat VPN deployment as a checkbox end up in CISA advisories.
Which side of that line your organization lands on depends on what you do this week.