Hostalive returns CRITICAL, yet reachable shows "yes"

Hello everybody,

I’ve got a problem with understanding how a host can (apparently) be both, DOWN (hence the hostalive check returning Critical) and reachable at the same time. Which information can I derive from this constellation, and where might possible errors regarding configuration or connectivity between my master and the host lie?

Thanks for any answers

Hello Daniel

Can you share with us the host object configuration and the service definition for the hostalive ?
Is the setup a distributed one or are you executing all the checks from the master ?

Hi Assaf,

thanks for helping me out here :slight_smile: The setup is partly distributed, but all checks for this specific machine are executed on the master node. The host object looks as follows

  object Host "[SRS]Router" {
    import "generic-host"
    address = ""
    vars.standort = "city"
    vars.os = ""
    vars.notification["mail"] = {
      users = [ "admins" ]
    groups = [ "iaas" ]

and the service object defining the hostalive-checks

  template CheckCommand "hostalive-common" {
    vars.ping_wrta = 3000.0
    vars.ping_wpl = 80

    vars.ping_crta = 5000.0
    vars.ping_cpl = 100

  object CheckCommand "hostalive" {
    import "ping"
    import "hostalive-common"

  object CheckCommand "hostalive4" {
    import "ping4"
    import "hostalive-common"

I hope this is helpful.

Hello Daniel

This might be unrelated to Icinga, but if the device is a router, is it possible it is blocking ICMP, while you can reach it on telnet/SSH or the other management ports (SNMP) used by the vendor ?

That might actually be it. So trivial I never thought of that, will look into it in a moment. In the meantime, do you happen to know why the host is marked as “reachable” anyways? How is Icinga determining if a host is reachable if ICMP is rejected?


The “reachable” status in the web interface is part of the dependency calculation.
It has nothing to do with the actual host state.

If you configure a router as a parent of a server you will see the “reachable” status of the server change to “no” in the web interface, in case the router goes DOWN.

The dependencies are used for limiting notifications of child hosts (e.g behind a central router/switch), so you don’t get bombarded with messages, if the central component is DOWN. You will then only get the notification for the parent host.


Thank you very much, I did not know this until now and it clarifies so much and opens new possibilities.