Error map
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 · layer 2, Network
Centre: this error. First ring: errors it is linked with (8). 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.
Directly related (8)
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.
Networking: Connection works, then fails after being idle — firewall/NAT idle timeout dropped the TCP session (use keepalive)
A connection that sat idle was forgotten by a firewall or NAT device, so the next packet gets reset or vanishes.
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.
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.
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.
Networking: IKE: received NO_PROPOSAL_CHOSEN — IPsec peers can't agree on encryption, hash or DH group
The two VPN gateways offered encryption settings that have nothing in common, so the tunnel never comes up.
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.
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.
Two steps away (23)
Error: connect ECONNREFUSED 127.0.0.1:5432
Nothing is listening at that host:port — the target service is down or you’re connecting to the wrong address.
HTTP 407 Proxy Authentication Required
A proxy between you and the server requires credentials before it will forward your request.
HTTP 408 Request Timeout
The server closed the connection because the client took too long to send the complete request.
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…
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: 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.
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.
Networking: kernel: nfs: server nas01 not responding, still trying / nfs: server nas01 OK
An NFS client can't get replies from the server, so processes using the mount hang in uninterruptible sleep.
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.
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.
Networking: VPN is connected but I can't reach the internal network — missing routes, split tunnel or overlapping subnets
The tunnel is up, but traffic for the office/VPC subnets isn't sent through it or comes back the wrong way.
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.
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.
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.
OpenSSL: error:14094410:SSL routines:ssl3_read_bytes:sslv3 alert handshake failure (SSL alert number 40)
The server aborted the handshake with alert 40 — no acceptable parameters (cipher, signature algorithm, client certificate or SNI…
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.
Networking: VPN connected but internal names like db.corp.local don't resolve — split DNS / 127.0.0.53 stub resolver not using the VPN DNS
The VPN works by IP, but internal hostnames fail because queries still go to your normal DNS server.
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.
HTTP 504 Gateway Timeout
A proxy or gateway waited too long for the upstream server to respond and gave up.
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…
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.
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.
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.
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