Error map

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

Networking · layer 2, Network

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Centre: this error. First ring: errors it is linked with (11). 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.

PING: transmit failed. General failure. — Networking: PING: transmit failed. General failure. / ping: sendmsg: Operation not permitted (Networking)PING: trans…WSL 2 installation is incomplete — Docker Desktop: WSL 2 installation is incomplete / WSL update required (Docker)WSL 2 installation …Network cable unplugged / NO-CARRIER — Networking: Network cable unplugged / `ip link` shows NO-CARRIER state DOWN / Ethernet: Network cable unplugged (Networking)Network cable unplu…Ping: Request timed out — Networking: ping — Request timed out / 100% packet loss (host drops or filters ICMP) (Networking)Ping: Request timed…The specified network name is no longer available (64) — Networking: Windows error 64: The specified network name is no longer available — SMB session dropped (Networking)The specified netwo…169.254.x.x self-assigned IP (DHCP failed) — Networking: IPv4 address 169.254.x.x (Autoconfiguration / APIPA) — the PC couldn't get an address from DHCP (Networking)169.254.x.x self-as…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 adapter fo…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.…Reply from x: TTL expired in transit — Networking: TTL expired in transit — routing loop between routers (Networking)Reply from x: TTL e…Frag needed and DF set (ICMP type 3 code 4) — Networking: ping: local error: message too long, mtu=1500 / Packet needs to be fragmented but DF set (Networking)Frag needed and DF …ICMP Destination unreachable (Port unreachable) — Networking: ICMP Destination unreachable (Port unreachable) — UDP packet sent to a port where nothing is listening (Networking)ICMP Destination un…Windows: Default gateway is not available — Networking: Windows: Default gateway is not available / Diagnose Connection Problems: DHCP not enabled (Networking)Windows: Default ga…not a git repository — fatal: not a git repository (or any of the parent directories): .git (Git)not a git repositorydaemon — Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running? (Docker)daemonauthor identity unknown — Author identity unknown *** Please tell me who you are. (Git)author identity unk…Network is unreachable — connect: Network is unreachable (ENETUNREACH) (Linux)Network is unreacha…ERR_INTERNET_DISCONNECTED — Chrome: No internet — ERR_INTERNET_DISCONNECTED (You are not connected to the internet) (Browser)ERR_INTERNET_DISCON…SFP link down / Loss of Signal (LOS) — Networking: Interface down — SFP transceiver Loss of Signal / no receive light (Networking)SFP link down / Los…1020 — Cloudflare Error 1020: Access Denied (Cloudflare)1020iptables: No chain/target/match — driver failed programming external connectivity on endpoint: iptables: No chain/target/match by that name (Docker)iptables: No chain/…ssh port 22 Connection timed out — ssh: connect to host x port 22: Connection timed out (Linux)ssh port 22 Connect…0x80070035 — 0x80070035: The network path was not found (System error 53) (Windows)0x80070035Connections hang on large transfers (PMTU black hole) — Networking: SSH/HTTPS connects but hangs on large data — path MTU discovery black hole (Networking)Connections hang on…Your Remote Desktop Services session has ended (network problem) — Networking: Your Remote Desktop Services session has ended. Possibly the network connection was lost / Remote Desktop disconnected, error code 0x904 (Networking)Your Remote Desktop…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…Wrong subnet mask: hosts can't reach each other — Networking: Two hosts on one LAN can't talk — subnet mask or network address mismatch (Networking)Wrong subnet mask: …DHCPDISCOVER ... No DHCPOFFERS received — Networking: dhclient: DHCPDISCOVER on eth0 ... No DHCPOFFERS received. No working leases in persistent database - sleeping. (Networking)DHCPDISCOVER ... No…captive portal — Browser: This network requires you to sign in — captive portal (hotel, airport, café Wi-Fi) blocking HTTPS sites (Browser)captive portalWi-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…arp -a shows (incomplete) — Networking: `arp -n` shows (incomplete) / Destination Host Unreachable — no ARP reply from the next hop (Networking)arp -a shows (incom…404 — HTTP 404 Not Found (HTTP)404405 — HTTP 405 Method Not Allowed (HTTP)405No route to host — connect: No route to host (EHOSTUNREACH) (Linux)No route to host1019 — Cloudflare Error 1019: Compute server error (Workers) (Cloudflare)1019554 5.4.14 Hop count exceeded - possible mail loop — SMTP: 554 5.4.14 Hop count exceeded - possible mail loop (Email / SMTP)554 5.4.14 Hop coun…OSPF neighbor stuck in EXSTART/EXCHANGE — Networking: %OSPF-5-ADJCHG: Nbr 10.0.0.2 from EXSTART to DOWN — OSPF neighbor stuck in EXSTART/EXCHANGE (MTU mismatch) (Networking)OSPF neighbor stuck…1033 — Cloudflare Error 1033: Argo Tunnel error (Cloudflare Tunnel not connected) (Cloudflare)1033cloudflared Unable to reach the origin service — cloudflared: Unable to reach the origin service. The service may be down or it may not be responding to traffic from cloudflared (502) (Cloudflare)cloudflared Unable …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…nc/telnet hangs: firewall DROP vs REJECT — Networking: nc -vz hangs then times out — firewall silently DROPs packets (REJECT would answer "Connection refused") (Networking)nc/telnet hangs: fi…UDP RcvbufErrors / packet receive errors — Networking: netstat -su: packet receive errors, receive buffer errors — UDP datagrams dropped by a full socket buffer (Networking)UDP RcvbufErrors / …dig: status: REFUSED (recursion not available) — Networking: dig: status: REFUSED / recursion requested but not available — the DNS server won't resolve queries for you (Networking)dig: status: REFUSE…502 — HTTP 502 Bad Gateway (HTTP)502504 — HTTP 504 Gateway Timeout (HTTP)504Cloudflare 502 — Cloudflare-branded 502 Bad Gateway / 504 Gateway Timeout ("cloudflare" footer) (Cloudflare)Cloudflare 502

Directly related (11)

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.

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.

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.

The specified network name is no longer available (64)Networking

Networking: Windows error 64: The specified network name is no longer available — SMB session dropped

A connection to a Windows file share was cut while in use.

169.254.x.x self-assigned IP (DHCP failed)Networking

Networking: IPv4 address 169.254.x.x (Autoconfiguration / APIPA) — the PC couldn't get an address from DHCP

With no DHCP answer, the computer gave itself a link-local 169.254.x.x address, which only works on the local segment.

No Wi-Fi adapter found / Wi-Fi option missingNetworking

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

The operating system doesn't see a working wireless adapter, so no networks can be listed.

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.

Reply from x: TTL expired in transitNetworking

Networking: TTL expired in transit — routing loop between routers

A packet ran out of hops before arriving, which usually means two routers keep sending it back and forth.

Frag needed and DF set (ICMP type 3 code 4)Networking

Networking: ping: local error: message too long, mtu=1500 / Packet needs to be fragmented but DF set

A packet is larger than the path MTU and is marked "don't fragment", so a router discards it.

ICMP Destination unreachable (Port unreachable)Networking

Networking: ICMP Destination unreachable (Port unreachable) — UDP packet sent to a port where nothing is listening

A host answered a UDP packet with an ICMP message saying no program is listening on that port.

Windows: Default gateway is not availableNetworking

Networking: Windows: Default gateway is not available / Diagnose Connection Problems: DHCP not enabled

The PC can't reach its router, so it has no path out of the local network.

Two steps away (33)

not a git repositoryGit

fatal: not a git repository (or any of the parent directories): .git

You ran a Git command outside a Git working tree.

daemonDocker

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

The docker CLI can’t talk to the Docker engine — it isn’t running, or your user can’t access the socket.

author identity unknownGit

Author identity unknown *** Please tell me who you are.

Git doesn’t know your name and email for commits.

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.

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.

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.

1020Cloudflare

Cloudflare Error 1020: Access Denied

A Cloudflare firewall/WAF custom rule blocked the request — the visitor’s IP, country, user agent or request pattern matched a bl…

iptables: No chain/target/matchDocker

driver failed programming external connectivity on endpoint: iptables: No chain/target/match by that name

Docker’s iptables rules were wiped (firewalld/ufw reload, iptables flush) while Docker was running, so it can’t publish ports.

ssh port 22 Connection timed outLinux

ssh: connect to host x port 22: Connection timed out

SSH packets get no reply — a firewall/security group drops them, the server is off, or the IP is wrong.

0x80070035Windows

0x80070035: The network path was not found (System error 53)

Windows can’t reach the shared folder — name resolution, SMB settings, firewall or network discovery is preventing it.

Connections hang on large transfers (PMTU black hole)Networking

Networking: SSH/HTTPS connects but hangs on large data — path MTU discovery black hole

Small packets pass but full-size ones vanish, so logins work and then transfers or page loads stall.

Your Remote Desktop Services session has ended (network problem)Networking

Networking: Your Remote Desktop Services session has ended. Possibly the network connection was lost / Remote Desktop disconnected, error code 0x904

An established Remote Desktop session dropped because the network under it stalled or the session was reset.

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.

Wrong subnet mask: hosts can't reach each otherNetworking

Networking: Two hosts on one LAN can't talk — subnet mask or network address mismatch

The hosts disagree about which addresses are local, so one tries to route traffic that should go straight across the LAN.

DHCPDISCOVER ... No DHCPOFFERS receivedNetworking

Networking: dhclient: DHCPDISCOVER on eth0 ... No DHCPOFFERS received. No working leases in persistent database - sleeping.

The client broadcast a DHCP request and no server answered.

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.

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.

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.

404HTTP

HTTP 404 Not Found

The server can’t find anything at the requested URL.

405HTTP

HTTP 405 Method Not Allowed

The URL exists, but it doesn’t accept the HTTP method you used (e.g. POST to a GET-only route).

No route to hostLinux

connect: No route to host (EHOSTUNREACH)

The destination host isn’t reachable — it’s down, on another subnet without routing, or a firewall rejects with “host unreachable…

1019Cloudflare

Cloudflare Error 1019: Compute server error (Workers)

A Cloudflare Worker routed the request to a loop or hit an internal compute error.

554 5.4.14 Hop count exceeded - possible mail loopEmail / SMTP

SMTP: 554 5.4.14 Hop count exceeded - possible mail loop

The message passed through too many mail servers (usually over 25), which almost always means two systems forward mail to each ot…

OSPF neighbor stuck in EXSTART/EXCHANGENetworking

Networking: %OSPF-5-ADJCHG: Nbr 10.0.0.2 from EXSTART to DOWN — OSPF neighbor stuck in EXSTART/EXCHANGE (MTU mismatch)

Two OSPF routers see each other but never finish exchanging databases, cycling between EXSTART and DOWN.

1033Cloudflare

Cloudflare Error 1033: Argo Tunnel error (Cloudflare Tunnel not connected)

The hostname routes to a Cloudflare Tunnel, but no healthy cloudflared connector is running for it.

cloudflared Unable to reach the origin serviceCloudflare

cloudflared: Unable to reach the origin service. The service may be down or it may not be responding to traffic from cloudflared (502)

The tunnel is connected, but cloudflared can’t reach your local service at the address in the ingress rule.

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.

nc/telnet hangs: firewall DROP vs REJECTNetworking

Networking: nc -vz hangs then times out — firewall silently DROPs packets (REJECT would answer "Connection refused")

A connection attempt gets no answer at all, which points to a firewall dropping the packets rather than a closed port.

UDP RcvbufErrors / packet receive errorsNetworking

Networking: netstat -su: packet receive errors, receive buffer errors — UDP datagrams dropped by a full socket buffer

UDP packets arrive faster than the application reads them, so the kernel throws the extras away.

dig: status: REFUSED (recursion not available)Networking

Networking: dig: status: REFUSED / recursion requested but not available — the DNS server won't resolve queries for you

The DNS server answered, but its policy refuses to look up names for your address.

502HTTP

HTTP 502 Bad Gateway

A proxy or gateway (Nginx, load balancer, CDN) got an invalid response — or no response — from the upstream server behind it.

504HTTP

HTTP 504 Gateway Timeout

A proxy or gateway waited too long for the upstream server to respond and gave up.

Cloudflare 502Cloudflare

Cloudflare-branded 502 Bad Gateway / 504 Gateway Timeout ("cloudflare" footer)

A plain-looking 502/504 page with “cloudflare” at the bottom comes from Cloudflare’s network itself (or an origin response it cou…