Diagnose HTTP 401 responses through a proxy by separating target authentication from proxy authentication, then checking WWW-Authenticate, token scope, session expiry, redirects, and request headers.
Diagnose proxy redirect loops by recording each Location header, scheme and host change, region decision, cache layer, and session-state dependency before changing exits.
When a proxy TLS handshake fails, separate proxy tunnel setup from SNI, certificate chain, trust-store, TLS version, and client-library errors before replacing the exit.
Proxy authentication setup should be verified before a client rollout. Use this checklist to separate username/password errors, IP whitelist gaps, protocol mismatch, and client-side configuration problems.
A proxy request timing baseline helps teams identify whether failures come from warm-up behavior, traffic bursts, retry pressure, timeout settings, or target-side throttling.
A practical proxy latency spike checklist for separating DNS lookup time, proxy connect time, TLS handshake, target response, retries, and real route quality before rotating IPs.
A practical proxy protocol mismatch checklist for teams separating HTTP, HTTPS, SOCKS5, authentication, DNS mode, and client support problems from real IP quality issues.
A practical proxy credential inventory checklist for teams that need to keep ports, protocols, regions, client settings, and ownership records aligned before scaling work.
Use this proxy error log template to record endpoint, client, DNS, location, latency, status code, and session evidence before replacing IPs.
Proxy timeout and connection refused errors need different fixes. Use this diagnostic order to check endpoint, protocol, DNS, authentication, client behavior, target limits, and proxy pool quality before rotating IPs.
