Error map

No Wi-Fi adapter found / Wi-Fi option missing Networking: No Wi-Fi networks found — the Wi-Fi adapter is missing, disabled or its driver failed

Networking · layer 2, Network

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Centre: this error. First ring: errors it is linked with (7). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.

No Wi-Fi adapter found / Wi-Fi option missing — Networking: No Wi-Fi networks found — the Wi-Fi adapter is missing, disabled or its driver failed (Networking)No Wi-Fi ad…ERR_INTERNET_DISCONNECTED — Chrome: No internet — ERR_INTERNET_DISCONNECTED (You are not connected to the internet) (Browser)ERR_INTERNET_DISCON…captive portal — Browser: This network requires you to sign in — captive portal (hotel, airport, café Wi-Fi) blocking HTTPS sites (Browser)captive portalNetwork cable unplugged / NO-CARRIER — Networking: Network cable unplugged / `ip link` shows NO-CARRIER state DOWN / Ethernet: Network cable unplugged (Networking)Network cable unplu…4-way handshake timeout / Incorrect password — Networking: wlan0: WPA: 4-way handshake failed - pre-shared key may be incorrect / WRONG_KEY (Networking)4-way handshake tim…PING: transmit failed. General failure. — Networking: PING: transmit failed. General failure. / ping: sendmsg: Operation not permitted (Networking)PING: transmit fail…arp -a shows (incomplete) — Networking: `arp -n` shows (incomplete) / Destination Host Unreachable — no ARP reply from the next hop (Networking)arp -a shows (incom…Wi-Fi keeps disconnecting (weak signal, -80 dBm) — Networking: Wi-Fi keeps disconnecting / signal -80 dBm / wlan0: deauthenticating by local choice (reason=3) (Networking)Wi-Fi keeps disconn…521 — Cloudflare Error 521: Web Server Is Down (Cloudflare)521522 — Cloudflare Error 522: Connection Timed Out (Cloudflare)522ERR_NETWORK_CHANGED — Chrome: Your connection was interrupted — A network change was detected. ERR_NETWORK_CHANGED (Browser)ERR_NETWORK_CHANGED407 — HTTP 407 Proxy Authentication Required (HTTP)407408 — HTTP 408 Request Timeout (HTTP)408Failed to fetch — TypeError: Failed to fetch / NetworkError when attempting to fetch resource (JavaScript)Failed to fetchNetwork is unreachable — connect: Network is unreachable (ENETUNREACH) (Linux)Network is unreacha…SFP link down / Loss of Signal (LOS) — Networking: Interface down — SFP transceiver Loss of Signal / no receive light (Networking)SFP link down / Los…Windows has detected an IP address conflict — Networking: Windows has detected an IP address conflict / Duplicate address detected by 00:aa:bb:cc:dd:ee (Networking)Windows has detecte…Port err-disabled (psecure-violation) — Networking: %PM-4-ERR_DISABLE: psecure-violation error detected on Gi0/5, putting Gi0/5 in err-disable state (Networking)Port err-disabled (…Cannot assign requested address (EADDRNOTAVAIL) — Networking: connect: Cannot assign requested address — ephemeral port range exhausted by TIME_WAIT connections (Networking)Cannot assign reque…WireGuard: Handshake did not complete after 5 seconds — Networking: Handshake for peer did not complete after 5 seconds, retrying (try 2) — WireGuard tunnel never establishes (Networking)WireGuard: Handshak…WSL 2 installation is incomplete — Docker Desktop: WSL 2 installation is incomplete / WSL update required (Docker)WSL 2 installation …Reply from 192.168.1.1: Destination host unreachable — Networking: ping — Destination Host Unreachable / Destination net unreachable (ICMP type 3) (Networking)Reply from 192.168.…Ping: Request timed out — Networking: ping — Request timed out / 100% packet loss (host drops or filters ICMP) (Networking)Ping: Request timed…Duplex mismatch: late collisions / CRC errors — Networking: Duplex mismatch — late collisions, runts and CRC errors on the switch port (Networking)Duplex mismatch: la…Native VLAN mismatch / wrong VLAN, no connectivity — Networking: %CDP-4-NATIVE_VLAN_MISMATCH / device on the wrong VLAN can't reach the gateway (Networking)Native VLAN mismatc…MAC flapping / broadcast storm (spanning tree loop) — Networking: %SW_MATM-4-MACFLAP_NOTIF: Host is flapping between ports / broadcast storm (Networking)MAC flapping / broa…Port forwarding not working (CGNAT / double NAT) — Networking: Port forwarding configured but the port stays closed — carrier-grade NAT (CGNAT) or double NAT (Networking)Port forwarding not…High TCP retransmissions / packet loss — Networking: netstat -s: segments retransmitted / Wireshark: TCP Retransmission, TCP Dup ACK — packet loss on the path (Networking)High TCP retransmis…

Directly related (7)

ERR_INTERNET_DISCONNECTEDBrowser

Chrome: No internet — ERR_INTERNET_DISCONNECTED (You are not connected to the internet)

Chrome sees no working network connection on the device, so it cannot load any page.

captive portalBrowser

Browser: This network requires you to sign in — captive portal (hotel, airport, café Wi-Fi) blocking HTTPS sites

The Wi-Fi needs a login or acceptance page first; until you complete it, secure sites fail with certificate or connection errors.

Network cable unplugged / NO-CARRIERNetworking

Networking: Network cable unplugged / `ip link` shows NO-CARRIER state DOWN / Ethernet: Network cable unplugged

The network card sees no electrical link, so nothing above it (IP, DNS, browser) can work.

4-way handshake timeout / Incorrect passwordNetworking

Networking: wlan0: WPA: 4-way handshake failed - pre-shared key may be incorrect / WRONG_KEY

The Wi-Fi association started but key negotiation failed, almost always a wrong password.

PING: transmit failed. General failure.Networking

Networking: PING: transmit failed. General failure. / ping: sendmsg: Operation not permitted

The operating system could not even send the packet, so the problem is local (adapter, route or firewall), not the remote host.

arp -a shows (incomplete)Networking

Networking: `arp -n` shows (incomplete) / Destination Host Unreachable — no ARP reply from the next hop

The machine asked "who has this IP?" and nobody on the local network answered.

Wi-Fi keeps disconnecting (weak signal, -80 dBm)Networking

Networking: Wi-Fi keeps disconnecting / signal -80 dBm / wlan0: deauthenticating by local choice (reason=3)

The wireless link is too weak or too noisy to hold, so the client drops and rejoins repeatedly.

Two steps away (20)

521Cloudflare

Cloudflare Error 521: Web Server Is Down

Cloudflare couldn’t connect to your origin — the connection was refused.

522Cloudflare

Cloudflare Error 522: Connection Timed Out

Cloudflare’s TCP connection to your origin timed out — the origin didn’t answer at all.

ERR_NETWORK_CHANGEDBrowser

Chrome: Your connection was interrupted — A network change was detected. ERR_NETWORK_CHANGED

The device switched networks (Wi-Fi to mobile data, VPN on/off, IP renewed) while the page was loading, so the browser aborted th…

407HTTP

HTTP 407 Proxy Authentication Required

A proxy between you and the server requires credentials before it will forward your request.

408HTTP

HTTP 408 Request Timeout

The server closed the connection because the client took too long to send the complete request.

Failed to fetchJavaScript

TypeError: Failed to fetch / NetworkError when attempting to fetch resource

The browser couldn’t complete the request at the network level — CORS, DNS, offline, blocked mixed content, or the server refused…

Network is unreachableLinux

connect: Network is unreachable (ENETUNREACH)

The host has no route to the destination network — no default gateway, interface down, or trying IPv6 without IPv6 connectivity.

SFP link down / Loss of Signal (LOS)Networking

Networking: Interface down — SFP transceiver Loss of Signal / no receive light

A fibre or SFP link is down because the transceiver receives no light.

Windows has detected an IP address conflictNetworking

Networking: Windows has detected an IP address conflict / Duplicate address detected by 00:aa:bb:cc:dd:ee

Two devices on the same network are using the same IP address, so traffic reaches the wrong one or neither.

Port err-disabled (psecure-violation)Networking

Networking: %PM-4-ERR_DISABLE: psecure-violation error detected on Gi0/5, putting Gi0/5 in err-disable state

The switch shut the port down because a security or protection feature detected a violation.

Cannot assign requested address (EADDRNOTAVAIL)Networking

Networking: connect: Cannot assign requested address — ephemeral port range exhausted by TIME_WAIT connections

The machine ran out of local ports for new outgoing connections to the same destination.

WireGuard: Handshake did not complete after 5 secondsNetworking

Networking: Handshake for peer did not complete after 5 seconds, retrying (try 2) — WireGuard tunnel never establishes

The WireGuard peers can't complete the cryptographic handshake, so no traffic flows.

WSL 2 installation is incompleteDocker

Docker Desktop: WSL 2 installation is incomplete / WSL update required

Docker Desktop on Windows needs WSL 2 and its Linux kernel; they’re missing, outdated or disabled.

Reply from 192.168.1.1: Destination host unreachableNetworking

Networking: ping — Destination Host Unreachable / Destination net unreachable (ICMP type 3)

A router (or your own PC) tells you it has no way to deliver the packet to that address.

Ping: Request timed outNetworking

Networking: ping — Request timed out / 100% packet loss (host drops or filters ICMP)

No echo reply arrived in time: the host is down, unreachable, or simply ignores ping.

Duplex mismatch: late collisions / CRC errorsNetworking

Networking: Duplex mismatch — late collisions, runts and CRC errors on the switch port

One side runs full duplex and the other half duplex, so the link works but is slow and drops packets.

Native VLAN mismatch / wrong VLAN, no connectivityNetworking

Networking: %CDP-4-NATIVE_VLAN_MISMATCH / device on the wrong VLAN can't reach the gateway

A port or trunk carries a different VLAN than expected, so hosts silently land on the wrong network.

MAC flapping / broadcast storm (spanning tree loop)Networking

Networking: %SW_MATM-4-MACFLAP_NOTIF: Host is flapping between ports / broadcast storm

A layer-2 loop is making frames circle the network, saturating links and making the whole VLAN crawl.

Port forwarding not working (CGNAT / double NAT)Networking

Networking: Port forwarding configured but the port stays closed — carrier-grade NAT (CGNAT) or double NAT

Your router forwards the port correctly, but another NAT in front of it (your ISP or a second router) blocks inbound connections.

High TCP retransmissions / packet lossNetworking

Networking: netstat -s: segments retransmitted / Wireshark: TCP Retransmission, TCP Dup ACK — packet loss on the path

Packets are being lost, so TCP resends them and throughput collapses.