ICMP / Ping Monitor

The ICMP monitor (often referred to as a "ping" check) verifies the basic reachability of a device over an IP network.

Configuration Options

When setting up an ICMP monitor, you can configure the following options:

Basic Settings

• Name: A descriptive name for your monitor.
• Group: Optional group assignment for organizing monitors.
• Interval (seconds): How frequently updu should send the ICMP echo requests.
• Timeout (seconds): The maximum time updu will wait for a reply before considering the ping failed.

ICMP Specific Settings

• Host / IP: The hostname or IP address of the target machine (e.g., 8.8.8.8 or router.local).
• Packet Count: The number of ICMP echo requests to send during each check interval. (Default is usually 1, but sending multiple can help mitigate transient packet loss).
• Packet Size (bytes): The size of the payload attached to the ICMP packet. Useful for testing MTU issues or specific network constraints.

Note: ICMP checks require that the device running updu has the necessary permissions to open raw sockets (or uses setcap cap_net_raw+ep). The official Docker image handles this automatically.

Example Use Cases

• Host Availability: Ensure your home server or Raspberry Pi is alive on the network, even if its web services have crashed.
• Gateway Check: Ping your ISP router to verify that your basic internet connection is online.