ETIMEDOUT networking network_error ai_generated true

TFTP: timeout waiting for data packet from 192.168.1.100:69

ID: networking/tftp-timeout-no-response

Also available as: JSON · Markdown · 中文
78%Fix Rate
82%Confidence
1Evidence
2023-07-22First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
tftp-hpa 5.2 active — — —
Cisco IOS 15.9 active — — —
Linux tftp client 0.17 active — — —

Root Cause

A TFTP client sent a read/write request to the server but received no data packet within the timeout period, typically due to firewall blocking UDP port 69, incorrect file path, or server overload.

generic

中文

TFTP客户端向服务器发送了读/写请求，但在超时时间内未收到数据包，通常由防火墙阻止UDP 69端口、文件路径错误或服务器过载引起。

Official Documentation

https://linux.die.net/man/1/tftp

Workarounds

  1. 85% success Check server connectivity with `tftp 192.168.1.100 -c get /path/to/file` and verify the server is running: `systemctl status tftpd-hpa` 
    Check server connectivity with `tftp 192.168.1.100 -c get /path/to/file` and verify the server is running: `systemctl status tftpd-hpa`
  2. 90% success Allow TFTP traffic through the firewall: `iptables -A INPUT -p udp --dport 69 -j ACCEPT` and ensure the TFTP server is not bound to localhost only. 
    Allow TFTP traffic through the firewall: `iptables -A INPUT -p udp --dport 69 -j ACCEPT` and ensure the TFTP server is not bound to localhost only.
  3. 80% success Test with a known good file in the server's root directory (e.g., /srv/tftp) to rule out permission issues: `chmod 644 /srv/tftp/test.txt` 
    Test with a known good file in the server's root directory (e.g., /srv/tftp) to rule out permission issues: `chmod 644 /srv/tftp/test.txt`

中文步骤

  1. Check server connectivity with `tftp 192.168.1.100 -c get /path/to/file` and verify the server is running: `systemctl status tftpd-hpa`
  2. Allow TFTP traffic through the firewall: `iptables -A INPUT -p udp --dport 69 -j ACCEPT` and ensure the TFTP server is not bound to localhost only.
  3. Test with a known good file in the server's root directory (e.g., /srv/tftp) to rule out permission issues: `chmod 644 /srv/tftp/test.txt`

Dead Ends

Common approaches that don't work:

  1. 75% fail

    If the firewall is blocking the port or the file does not exist, no amount of waiting will help; the request will still fail after the extended timeout.

  2. 60% fail

    The client implementation is rarely the issue; the problem is almost always server-side or network-layer.

  3. 50% fail

    This is a security risk and may not solve the problem if the server's firewall is the blocker; also, it does not verify the server is running.