Areas grouped by OSI layer, from cabling to ISP services. Every category ends with Add Other for an area of your own. You tick the areas involved and, for each one, give its technical data, the problems observed, the failed tests (expected and actual result), the successful tests and your observations, then rank the problems by urgency. The AI correlates the evidence, builds hypotheses (failed tests strengthen them, successful tests eliminate them), starts with your most urgent problem, sets the investigation path and, for each problem, guides the root cause analysis and gives the best correction now and the corrective action decision.
Contents
1. Evidence Correlation
2. Problem Prioritization
3. Root Cause Hypotheses
4. Optimal Investigation Path
5. Problem-by-Problem Resolution
6. Missing Diagnostic Information
What you provide
Relevant areas — The areas concerned by the incident.
Cabling — Cable type, cable length (m), cable path (from → to), then the problems seen and the tests run.
Fiber — Fibre type, connector, optical power TX (dBm), then the problems seen and the tests run.
Physical Ports — Device, ports concerned, port state, then the problems seen and the tests run.
SFP / Transceivers — Transceiver model, vendor coding, tX power (dBm), then the problems seen and the tests run.
Hardware Connectivity — Device, vendor and model, power, then the problems seen and the tests run.
Patch Panels — Patch panel, panel ports concerned, labelling matches the documentation, then the problems seen and the tests run.
Additional component (OSI Layer 1 - Physical) — A component not listed above: its name, role, vendor and configuration, then the problems seen and the tests run.
VLAN — VLAN ID, vLAN Name, subnet, then the problems seen and the tests run.
Switching — Switch, model and firmware, cPU usage (%), then the problems seen and the tests run.
STP — Mode, root bridge, expected root bridge, then the problems seen and the tests run.
Port Configuration — Port, mode, access VLAN, then the problems seen and the tests run.
Trunking — Trunk link, allowed VLANs, native VLAN, then the problems seen and the tests run.
MAC Addressing — MAC address concerned, expected port, port where it is learned, then the problems seen and the tests run.
ARP — IP address concerned, expected MAC address, mAC address seen in the ARP table, then the problems seen and the tests run.
Additional component (OSI Layer 2 - Data Link) — A component not listed above: its name, role, vendor and configuration, then the problems seen and the tests run.
Routing — Source Network, destination Network, routing Protocol, then the problems seen and the tests run.
Subnetting — Subnet, mask / prefix, mask configured on the device, then the problems seen and the tests run.
Gateway — Gateway address, redundancy, active device, then the problems seen and the tests run.
IP Addressing — IP address concerned, assignment method, iP conflict detected, then the problems seen and the tests run.
ICMP — Source, destination, ping result, then the problems seen and the tests run.
NAT — NAT device, nAT type, inside address and port, then the problems seen and the tests run.
Additional component (OSI Layer 3 - Network) — A component not listed above: its name, role, vendor and configuration, then the problems seen and the tests run.
TCP — Destination (IP:port), connection result, retransmissions, then the problems seen and the tests run.
UDP — Flow (source → destination:port), application, loss (%), then the problems seen and the tests run.
Port Communication — Source, destination, destination port, then the problems seen and the tests run.
Session Establishment — Protocol / application, session established, drops after (time), then the problems seen and the tests run.
Load Balancing — Virtual service (VIP:port), pool state, health check, then the problems seen and the tests run.
Additional component (OSI Layer 4 - Transport) — A component not listed above: its name, role, vendor and configuration, then the problems seen and the tests run.
VPN Sessions — VPN type, peers / gateway, tunnel state, then the problems seen and the tests run.
Authentication Sessions — Authentication system, session lifetime / timeout, sessions end after, then the problems seen and the tests run.
Additional component (OSI Layer 5 - Session) — A component not listed above: its name, role, vendor and configuration, then the problems seen and the tests run.
Encryption — Encrypted flow, algorithms / cipher suites configured, mismatch reported by a peer, then the problems seen and the tests run.
SSL/TLS — Host / service, tLS versions allowed, tLS inspection on the path, then the problems seen and the tests run.
Certificates — Certificate subject / host, issuer (CA), expiry date, then the problems seen and the tests run.
Additional component (OSI Layer 6 - Presentation) — A component not listed above: its name, role, vendor and configuration, then the problems seen and the tests run.
DNS — DNS Server, forwarders, resolution Failures, then the problems seen and the tests run.
DHCP — DHCP server, scope, scope usage (%), then the problems seen and the tests run.
Firewall — Vendor, model, firmware Version, then the problems seen and the tests run.
Proxy — Proxy, pAC file / explicit configuration, category or rule involved, then the problems seen and the tests run.
NAC — NAC solution, authentication method, authentication result, then the problems seen and the tests run.
WLAN / WiFi — SSID, aP Name, frequency Band, then the problems seen and the tests run.
Endpoints — Device, operating system, iP configuration, then the problems seen and the tests run.
Authentication — Authentication system, error message, clock synchronised, then the problems seen and the tests run.
Applications — Application, server, uRL or host name, then the problems seen and the tests run.
APIs — API endpoint, hTTP status, response time (ms), then the problems seen and the tests run.
ISP Services — Provider, circuit / contract ID, service concerned, then the problems seen and the tests run.
Additional component (OSI Layer 7 - Application) — A component not listed above: its name, role, vendor and configuration, then the problems seen and the tests run.
Problem prioritisation — The analysis investigates the problems in this order, weighed by their business impact.
