Network error overview
What “Network error overview” usually means
When PuTTY reports Network error overview, the client has already attempted a network or protocol step and failed before a normal interactive shell is available. This guide explains what the message usually means on Windows clients, which local settings to verify first, and when the problem is almost certainly on the server, firewall, or DNS path rather than inside the PuTTY GUI.
Generic network failure class covering refused, reset, abort, and related socket errors. Read the full dialog text—PuTTY usually includes a more specific clause that maps to a dedicated guide on this site.
Independent resource: Putty.info is educational only and is not affiliated with the official PuTTY project. Compare symptoms against the official documentation for your installed version.
Symptoms you will see
Operators usually notice this failure in one of a few repeatable ways. Capture the exact dialog text, the hostname and port from the Session panel, and whether the failure happens before or after a username prompt—those details decide which checklist below applies.
- Error dialog titled or containing Network error.
- Failure before interactive shell with little SSH-level detail.
Likely causes ranked by frequency
Several independent conditions can produce the same client-facing wording. Work from the outside in: reachability first, protocol selection second, authentication third. Changing key files will not fix a TCP refusal, and opening a wider firewall will not fix a rejected public key.
- Underlying TCP problems (firewall, routing, reset).
- Local security software intercepting sockets.
- Sleeping NIC or flaky Wi-Fi mid-connect.
Step-by-step client checks
Use this ordered checklist on a workstation you control. Prefer saved sessions so Host Name, Port, and Connection type stay consistent while you isolate one variable at a time.
- Copy the exact subcategory text and open the matching /errors/ page.
- Retry wired vs wireless and with VPN toggled deliberately.
- Disable experimental proxy settings under Connection → Proxy if not required.
- Update to current stable PuTTY from official hosts if the client is ancient.
- Test with Plink -v for verbose clues without pasting secrets into websites.
- Collect corporate proxy PAC requirements if you are on a locked-down network.
Do not paste private keys, passphrases, or production passwords into Putty.info tools or contact forms. Diagnose locally with PuTTY, Plink, PSCP, or PSFTP from an official install.
When it is a server or network issue
Correlate with firewall deny counters and load balancer resets. Generic client messages often reflect middlebox policy.
If TCP connects from another network path but fails from yours, involve the network team with traceroute/path evidence rather than repeatedly regenerating keys. If authentication fails after a banner appears, collect the server sshd logs for the same timestamp and username—client-side retries alone rarely reveal AccountLocked, Match blocks, or AllowUsers denials.