[Kea-users] ping-check-hooks – global vs subnet level enable-ping-check behavior

[Dipesh Kayastha]

Hello Kea team,

I am testing the libdhcp_ping_check.so hook library and observed some
behavior I’d like clarification on.

My configuration:
"hooks-libraries": [
  {
    "library": "libdhcp_ping_check.so",
    "parameters": {
      "enable-ping-check": true
    }
  }
],

"subnet4": [
  {
    "subnet": "20.20.20.0/24",
    "user-context": {
      "enable-ping-check": false
    },
    "pools": [
      {
        "pool": "20.20.20.8 - 20.20.20.10"
      }
    ]
  }
]

Expectation:

   -

   Since I set "enable-ping-check": false at the *subnet level*, I expected
   no ICMP checks for leases in that subnet/pool.

Observation:


   -

   When running the server and requesting a lease, I still see ping-check
   activity in the logs:
   -

   2025-08-29 07:00:33.476 DEBUG [kea-dhcp4.ping-check-hooks]
   PING_CHECK_MGR_START_PING_CHECK for 20.20.20.8 ...
   2025-08-29 07:00:33.477 DEBUG [kea-dhcp4.ping-check-hooks]
   PING_CHECK_CHANNEL_ECHO_REQUEST_SENT to address 20.20.20.8
   2025-08-29 07:00:33.577 DEBUG [kea-dhcp4.ping-check-hooks]
   PING_CHECK_MGR_REPLY_TIMEOUT_EXPIRED for 20.20.20.8 ...
   2025-08-29 07:00:33.577 DEBUG [kea-dhcp4.ping-check-hooks]
   PING_CHECK_MGR_LEASE_FREE_TO_USE address 20.20.20.8 ...

Question:

   -

   Is this the *intended behavior* (global parameter overriding
   subnet-level user-context),
   or should the "enable-ping-check": false at subnet level disable ICMP
   checks for that subnet?

Thanks in advance for clarification.

Regards,
Dipesh
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