Blackbox ICMP Probe not working properly.

[yagyans...@gmail.com]

Hi. I am using blackbox exporter version 0.18.0 and using ICMP module to check for Host Downs in my environment. I have started noticing a discrepancy from past few days that sometimes when the host is down actually Blackbox still returns probe_success as true.

On getting into it further, I found out that for some of my targets I am observing last log line for ICMP probe in the Blackbox logs 7 days ago, 2 days ago for some etc. So, I assume blackbox has not sent a ICMP requests since 7 days to that target and hence it kept on giving the information it got whenever it last sent it.

What could be the reason for it?

Sample example. Today is 7th March and last Probe Succeeded for this target is on March 2, not failures or success after that.

Mar  2 22:22:37 infra-prometheus-n2 blackbox_exporter: ts=2021-03-02T16:52:37.982Z caller=main.go:169 module=icmp_prober target=x.x.x.x level=debug msg="Probe succeeded" duration_seconds=0.001848452

Here is the module configuration:

  icmp_prober:
   prober: icmp
   timeout: 30s
   icmp:
     preferred_ip_protocol: ip4

Please help. Thanks in advance!

[Marcelo Magallón]

What happens if you hit BBE directly, e.g.

$ curl http://.../probe?target=x.x.x.x&module=icmp_prober

Does it return the expected values? If yes, are you sure the Prometheus configuration is correct?

-- 

Marcelo