# See external infrastructure issues before your customers do. > External attack surface monitoring + uptime checks for MSPs, telcos, and infrastructure teams. Detect incidents before your customers do. Canonical: https://sentryxmonitor.com/ Last updated: 2026-08-08 Continuously monitor internet-facing services, certificates, DNS, availability, and exposure changes—without agents or internal credentials. No agents required Read-only scanning Regional verification No credentials needed [Scan a domain free](https://sentryxmonitor.com/#scanForm) [View sample report](https://sentryxmonitor.com/report/?domain=example.com&entry=sample-report) External Security Scan 82 / 100 company.com Assets www.company.com api.company.com vpn.company.com mail.company.com Recent Findings HTTPS unavailable · vpn.company.com SSL expires in 21 days · api.company.com HTTP header missing · www.company.com DNS discovery completed SSL inspection completed Security header analysis running Report generation running ## Built for teams responsible for internet-facing systems. Start with public evidence, then turn important endpoints into continuous monitoring. ### MSPs & Managed Service Providers Review customer-facing exposure and monitor critical endpoints from one operational view. ### Telcos & Cloud Providers Track public services, HTTPS endpoints, certificates, and infrastructure changes. ### Hosting Operators Find customer-facing issues earlier and keep evidence ready for incident response. ### Infrastructure Teams Maintain a current view of externally visible services without replacing internal observability. **Clear scope** Sentryx observes public infrastructure from the outside. It complements—not replaces—internal observability, vulnerability management, or penetration testing. ## Discover exposure. Monitor availability. Detect change. One workflow for the evidence operators need before, during, and after an incident. Discover exposure Build a public view of reachable hosts, DNS records, HTTPS services, and certificate evidence. Monitor availability Continuously check critical websites, APIs, endpoints, and certificate validity from outside your network. Detect change See when DNS, certificates, or externally visible services change so teams can investigate with context. ## From free evidence to continuous monitoring. No agent or internal network access is required for the public scan. 01 Enter a domain Use a public domain you are authorised to assess. → 02 Discover evidence Bounded DNS, HTTPS, and certificate checks. → 03 Review the report Evidence, limits, and practical next steps. → 04 Monitor continuously Discuss ongoing monitoring with our team. ## Your External Security in One View Turn scattered external security signals into a single view of your attack surface, monitoring health, and issues requiring attention. Security Overview 84 Good · ↑ 6 this month 36 Assets 427 Monitors 12 Issues 2 Critical Security Score Trend Monitor Availability 99.98% Findings Critical 2 High 3 Medium 7 Low 12 Recent Activity New port detected · vpn.company.com 2 min ago SSL certificate renewed · api.company.com 18 min ago Website recovered · portal.company.com 34 min ago DNS change detected · company.com 1 hour ago Continuous monitoring ## Need monitoring beyond a one-time report? Tell us about your environment. Our business team will recommend a practical scope based on assets, locations, and operational needs—without forcing a public plan choice. Asset volume Monitoring locations Alerting workflow Reporting needs [Discuss continuous monitoring](https://sentryxmonitor.com/#commercial) [Run the free scan](https://sentryxmonitor.com/#scanForm) ## Security Intelligence - [](https://sentryxmonitor.com/services/external-attack-surface-monitoring/) - [](https://sentryxmonitor.com/research/common-exposed-ports/) - [](https://blog.sentryxmonitor.com/why-outside-in-monitoring-matters/) ## Questions operators ask before starting. ### Does Sentryx need internal access? No. External monitoring uses public signals and does not require VPN access, cloud administrator credentials, or an installed agent. ### What can I monitor? Websites, APIs, DNS, TLS certificates, domains, supported services, and externally visible changes. ### Does this replace penetration testing? No. Sentryx provides broad continuous visibility. Authorized penetration testing validates specific attack paths at a point in time. ### What data does the free scan retain? The scan processes public response evidence and stores report metadata needed to operate and protect the service. It does not retain response bodies or collect credentials. ### Can a proxy hide the origin? Yes. CDNs and reverse proxies can hide origin infrastructure, so findings describe what Sentryx can observe publicly—not every internal asset. ### Is Sentryx currently certified? Sentryx is not currently SOC 2 or ISO 27001 certified. Security controls and data handling are described without implying certification. ## Related - [Home](https://sentryxmonitor.com/)