SSL VPN operates over HTTPS on port 443 and is accessible from virtually any network because it uses the same port as normal web traffic. It is easy to deploy for remote users and requires minimal client software. IPsec VPN creates an encrypted tunnel at the network layer and is typically used for site-to-site connections and high-performance scenarios where full tunnel access is needed without the overhead of SSL negotiation. Most organizations use SSL VPN for remote workers and IPsec VPN for permanent site-to-site connections.

Zero Trust Network Access (ZTNA) grants access to specific applications rather than putting users on the network. A traditional VPN places the authenticated user inside the network perimeter and trusts that they will only access what they are supposed to. ZTNA verifies identity and device posture before every application access request and never exposes the broader network to the remote device. This means a compromised remote device cannot be used to move laterally to other systems, which is the most common path ransomware takes through VPN-connected environments.

VPN user capacity varies widely. Entry-level firewall appliances with built-in VPN typically support 10 to 100 concurrent users. Mid-range appliances handle 100 to 500 users. Dedicated VPN concentrators like SonicWall SMA 500v and SMA 8200v scale from several hundred to over 20,000 concurrent users depending on the license tier. Always size for your expected peak concurrent sessions, not your total user count, because not all users will be connected at the same time.

Yes, without exception. VPN credentials are a top target for credential stuffing and phishing attacks because a valid username and password alone grants broad network access. Multi-factor authentication adds a second verification step that blocks unauthorized logins even when credentials are compromised. Most cyber insurance policies now require MFA on VPN access as a baseline condition for coverage. All major VPN platforms we carry integrate with TOTP, RADIUS, and Duo for MFA enforcement.

SonicWall Secure Mobile Access (SMA) is a dedicated remote access appliance designed for organizations that need more VPN capacity or more granular access control than what is built into a standard firewall. SMA provides SSL VPN, ZTNA, policy-based access control by user, device, location, and time-of-day, device posture checking before allowing access, and application-level granular policies. It is the right choice when you have more than a few dozen concurrent VPN users, compliance requirements that mandate access logging and policy enforcement, or a need for clientless browser-based access for contractors and BYOD users.