# See the public systems connected to your domain.

> Discover public subdomains, DNS, HTTPS, TLS certificates, and exposed services. Review evidence, identify unknown assets, and monitor what matters.

Canonical: https://sentryxmonitor.com/services/external-attack-surface-monitoring/
Last updated: 2026-07-30

Exposure monitoring

Sentryx provides an outside-in view of public domains, subdomains, DNS, HTTPS, TLS certificates, and exposed services. Review the evidence, identify unknown assets, and turn important endpoints into monitors.

[Open the sample report](https://sentryxmonitor.com/report/) [Explore uptime monitoring](https://sentryxmonitor.com/services/uptime-monitoring/)

Discovery preview read-only

**api.company.com**Cloud provider · TLS valid

monitor

**vpn.company.com**443 open · certificate age 326d

review

**old-admin.company.com**service signal observed

review

**mail.company.com**public DNS and host observed

known

What discovery can reveal

## Find assets that are missing from the monitoring plan.

Customer-facing risk often sits outside the documented inventory: a staging host, an old subdomain, a public service, or a certificate that no team actively owns.

### Domains and subdomains

Map public hostnames connected to the organization, then separate expected assets from unknown hosts and monitoring candidates.

### Public service signals

Review internet-facing service evidence that may point to administration tools, legacy systems, public APIs, or infrastructure that needs an owner.

### DNS, hosting, and TLS context

Combine DNS, provider, region, IP, certificate, and TLS evidence so each finding is easier to triage and explain.

From discovery to action

## Turn important public assets into monitored endpoints.

A static inventory is useful. It becomes operational when selected assets become uptime, SSL certificate, DNS, TCP, HTTP, or keyword checks with evidence-based alerts.

**01****Scan a domain**

Start with a public domain. The scan is read-only and does not require an agent.

**02****Review the evidence**

Separate expected assets, unknown hosts, service signals, and certificate risks.

**03****Monitor what matters**

Turn important endpoints into checks with the appropriate method and interval.

**04****Share the context**

Give owners and clients the host, timing, IP, provider, and failure evidence they need.

Free domain scan

## See what your domain exposes today.

No signup required · read-only · initial results in seconds

## Related
- [Home](https://sentryxmonitor.com/)