Extending Observability Beyond Firewalls: A Guide to Secure Telemetry Collection

In modern enterprise environments, observability no longer lives inside a single network. Organizations rely on telemetry from branch offices, cloud workloads, OT networks, and even air-gapped systems. However, collecting and routing that data across security zones often presents an impossible choice: compromise security or sacrifice visibility.

Tavve’s ZoneRanger was built to solve this problem. It enables secure, policy-compliant observability across boundaries, without requiring inbound firewall rules or complex workarounds. Whether you’re supporting zero trust architecture or just trying to avoid firewall change fatigue, this is your guide to collecting telemetry without opening the door to risk.

The Challenge: Observability Across Security Boundaries

Security teams have long adopted perimeter segmentation to reduce risk. In zero trust environments, this segmentation becomes even more granular. While good for security, it complicates observability.

Consider these common scenarios:

• Monitoring SNMP traps from remote sites
• Sending syslog or NetFlow from OT networks to a central SIEM
• Collecting performance data from devices that sit behind firewalls

Each case requires telemetry to cross a security boundary. But most tools expect an open port, direct IP access, or relaxed firewall policies. For many organizations, that is a nonstarter.

Traditional workarounds—like VPN tunnels, NAT, or out-of-band collectors—are either fragile or high-maintenance. Worse, they often violate internal security standards or fail compliance checks.

ZoneRanger offers a secure alternative that aligns with modern network architecture and enterprise security policies.

How ZoneRanger Works

ZoneRanger acts as a secure gateway that proxies telemetry data across network boundaries. It is designed to be deployed in line with your firewalls, allowing you to route SNMP, NetFlow, syslog, and other UDP-based protocols across zones safely.

Key features include:

• No open inbound ports
• Full control over which devices and data are allowed to pass
• Support for overlapping IP addresses
• Compatibility with any telemetry consumer (SIEM, APM, NMS)

Instead of creating direct connections between devices, ZoneRanger establishes outbound sessions from within each zone. This keeps control with the security team while enabling full observability for operations and engineering.

Use Case: Monitoring Remote ATMs Without Compromising Security

A large financial institution needed to monitor thousands of ATMs across North America. Each ATM lived on a segmented network behind a firewall. Opening ports for SNMP or syslog data was not an option.

With ZoneRanger, they deployed a lightweight gateway near each security boundary. These gateways forwarded telemetry securely to the central monitoring system, without exposing devices to external traffic.

The result:

• 95% reduction in firewall rule complexity
• No risk of lateral movement from compromised zones
• Full observability into ATM behavior and health

This approach also aligned with their zero trust model, helping them meet both security and compliance objectives.

Why Inbound Rules Are a Risk

Opening inbound firewall rules to allow telemetry access may seem like a small exception. But it creates a pathway for reconnaissance, fingerprinting, and exploitation.

ZoneRanger was designed to avoid this entirely. Instead of relying on inbound access, it uses encrypted, authenticated outbound sessions initiated from the trusted side. This prevents attackers from probing the network or manipulating telemetry feeds.

It also simplifies operations. There is no need to constantly submit firewall change requests, validate rule sets, or worry about misconfigurations exposing critical infrastructure.

Secure Protocol Support, Out of the Box

ZoneRanger supports a wide range of telemetry protocols, including:

• SNMP (v1, v2c, v3)
• NetFlow and sFlow
• Syslog (TCP and UDP)
• ICMP, traps, and more

It can handle both polling-based and trap-based telemetry, meaning you can forward alerts, usage data, and diagnostic events in real time. It also works with all major observability and security tools, including Splunk, Datadog, Cisco Secure Network Analytics (formerly Stealthwatch), SolarWinds, and others.

This means you can route telemetry to your existing stack without requiring custom integrations or source-side changes.

Overlapping IP Support: One of ZoneRanger’s Secret Weapons

In large enterprise environments, IP address conflicts across zones are common. For example, two separate branch networks may both use the 10.0.0.0/8 range.

ZoneRanger handles this by acting as a proxy. It creates a virtual address space for each zone, allowing you to monitor devices with conflicting IPs without requiring readdressing or NAT.

This is especially useful in OT and manufacturing environments, where re-IP’ing legacy devices is often impossible.

Designed for Zero Trust and Hybrid Environments

ZoneRanger aligns directly with zero trust principles:

• No implicit trust between zones
• Access is controlled, auditable, and minimal
• Visibility does not require exposure

It also supports hybrid architectures. Whether your environment spans on-prem, cloud, or air-gapped facilities, ZoneRanger gives you a unified approach to telemetry forwarding and observability.

It enables compliance with NIST, PCI, and other security frameworks by ensuring only necessary data crosses boundaries, and that it does so in a controlled, monitored fashion.

Deployment Benefits: Fast ROI and Minimal Friction

Organizations deploying ZoneRanger report measurable benefits within weeks:

• Over 90% reduction in firewall change requests
• No need to deploy additional agents or appliances
• Simplified routing and telemetry infrastructure
• ROI in less than six months due to reduced engineering effort

You also gain control and auditability. ZoneRanger logs who is accessing what, when, and how, which supports compliance audits and forensic investigations.

Better Together: ZoneRanger and PacketRanger

While ZoneRanger handles secure boundary traversal, PacketRanger manages filtering, routing, and statistical analysis across your internal telemetry pipeline.

Together, they offer a complete observability platform:

• ZoneRanger enables secure data collection across boundaries
• PacketRanger filters and enriches that data before it hits your tools

This pairing reduces cost, complexity, and risk across your entire telemetry workflow.

Most observability tools force you to choose between visibility and security. ZoneRanger lets you have both.

You no longer need to poke holes in your firewall to get telemetry from critical devices. You can collect SNMP, NetFlow, and syslog data from across your entire environment—securely, consistently, and without compromise.

If your organization is struggling with blind spots, firewall bottlenecks, or compliance concerns, it’s time to rethink how telemetry flows through your network.

Learn more about ZoneRanger or schedule a demo to see how it works in your environment.