39D The 39D Network ToolboxPublic network diagnostics and routing intelligence

NETWORK ENGINEERING • DNS • BGP • CYBER SECURITY

See what the internet sees.

Run external diagnostics from the 39D test server, inspect routing and DNS data, and troubleshoot public services without installing specialist software.

Run a ping test Open BGP looking glass
Public targets onlyRate limitedNo browser pluginsUK network expertise

FREE ONLINE TOOLS

Choose a network test

Connectivity

Ping TestMeasure packet loss and round-trip latency from the 39D test server. TracerouteDisplay the network hops between the 39D server and a public destination. MTR Network TestCombine repeated ping measurements with route visibility. Network Latency GraphVisualise a short series of latency measurements and packet loss. IPv6 Connectivity TestCheck AAAA records and test reachability over IPv6. Limited TCP Port CheckerTest a controlled list of common TCP service ports.

DNS & Email

DNS LookupLook up common DNS record types for a domain. Reverse DNS LookupFind PTR hostnames associated with public IP addresses. DNS Propagation CheckerCompare DNS answers from several independent public resolvers. DNSSEC ValidationCheck DNSSEC validation status and inspect signed DNS answers. SPF Record CheckerInspect SPF syntax, mechanisms and DNS lookup pressure. DKIM Record CheckerLook up a DKIM selector and inspect its public key record. DMARC Record InspectorInspect the DMARC policy published at _dmarc.domain. DNS Blocklist CheckCheck public IP reputation against RIPEstat DNS blocklist data.

Ownership & Routing

WHOIS LookupQuery domain or IP registration information from the server. Reverse WHOIS SearchSearch domain records by WHOIS email, organisation or name using an optional provider API. ASN LookupFind the originating ASN and network information for an IP or ASN. IP Geolocation LookupInspect the registration country and optional geolocation estimate for a public IP address.

Web & TLS

HTTP Status CheckTest HTTP or HTTPS status, redirect behaviour and timing. HTTP Header CheckerInspect response headers and common browser-security controls. SSL Certificate InspectorInspect the live TLS certificate presented by a public host. Website Speed TestMeasure DNS, connect, TLS, first-byte and total response timing.

BGP & Routing

BGP Route LookupInspect current routing status for an IP prefix or ASN. BGP Looking GlassView routes and AS paths observed by RIPE RIS collectors. RIPE RIS Route ViewerView BGP route state observed across RIPE RIS collectors. BGP Prefix Validation: RPKI & IRRCompare a prefix/origin announcement with RPKI and routing-registry data.

Monitoring

Historical Response-Time MonitoringView stored availability and response-time samples collected by the included cron job.

BUILT BY NETWORK OPERATORS

Diagnostics backed by real MSP and ISP experience

The toolbox is provided by 39D and brings together practical checks used when supporting business IT, cyber security, internet connectivity, VoIP, DNS and BGP routing. For managed support or project work, visit 39D and 39T.

Why server-side network tests matter

A local test tells you what your own device and broadband connection can see. A server-side test gives a second observation point. Comparing the two helps separate a local firewall, DNS resolver or access-network problem from a wider issue affecting a public service.

The 39D Network Toolbox validates destinations before running a test. Public installations block private, loopback, reserved and link-local addresses by default, and expensive operations are separately rate limited.

Routing and DNS intelligence in one place

Traditional diagnostic sites often stop at ping, traceroute and basic DNS. This toolbox also includes RIPE RIS route views, BGP looking-glass data, ASN information, RPKI origin validation, IRR consistency, DNSSEC, email authentication and historical response-time storage.

Each tool has a dedicated, indexable page with usage guidance, common interpretation mistakes and related checks so the site can grow as a useful technical reference rather than a single form.