Linux Remote host Down

[john.akash]

Hello Team,

I have configured a nagios server 4.0.3 on a Amazon Linux server and added a CentOS server as remote host. All of the services (The services which are configured to monitor are: Current Load, Current Users, HTTP, Root Partition, Total Processes) status are showing OK but the server status is showing as DOWN. The status information showing on the nagios web console is (Host check timed out after 30.01 seconds). how can I resolve this issue?

My host configuration is
define host{
use linux-server
host_name server1
alias server1
address XX.XX.XX.XX
}

define hostgroup{
hostgroup_name linux-servers
alias Linux Servers
members server1
}



define service{
use local-service
host_name server1
service_description PING
check_command check_ping!100.0,20%!500.0,60%
}


define service{
use local-service
host_name server1
service_description Root Partition
check_command check_local_disk!20%!10%!/
}


define service{
use local-service
host_name server1
service_description Current Users
check_command check_local_users!20!50
}

define service{
use local-service
host_name server1
service_description Total Processes
check_command check_local_procs!250!400!RSZDT
}

define service{
use local-service
host_name server1
service_description Current Load
check_command check_local_load!5.0,4.0,3.0!10.0,6.0,4.0
}

define service{
use local-service
host_name server1
service_description Swap Usage
check_command check_local_swap!20!10
}

define service{
use local-service
host_name server1
service_description SSH
check_command check_ssh
notifications_enabled 0
}

define service{
use local-service
host_name server1
service_description HTTP
check_command check_http
notifications_enabled 0
}

[slansing]

Interesting, the host does not even show up properly in the web interface, by what method are you accessing the host details page for it? Can you manually run check ping against it from the Nagios server's command line? If so, what is the output?

[john.akash]

Hello Slansing,
Thanks for the response, the host name was shown up there with the name which we have configured but the host status shows as DOWN. The ping response was blocked in the remote server, I have enabled it and check the ping with command line and is worked fine. The status in the nagios server dash board was OK. Even after that the remote host status is DOWN .

Could you please let me know which is the parameter / command used in nagios core 4.0.3 to check whether the remote host is UP or DOWN?

The application versions which I used for configuration
Nagios Core: 4.0.3
Nagios Plugins: 2
Nrpe: 2.15

Interesting, the host does not even show up properly in the web interface, by what method are you accessing the host details page for it? Can you manually run check ping against it from the Nagios server's command line? If so, what is the output?

Hello Slansing,
The interface showing the host (i masked for security purpose) and the status is DOWN. The ping response is blocked in the remote server.

Could you please let me know which service check determine whether a remote server is UP or DOWN?

My Nagios configuration details
Nagios Core: 4.0.3
Nagios plugin: 2.0
Nrpe: 2.15

[slansing]

Services are not used to determine a host's reachability, hosts generally have their own checks assigned, and that is typically (highly dependent on what you have set up for commands) a ping check to tell if the host is reachable, or unreachable, the average time it takes for icmp data to be sent and returned, and it's latency over the wire. So you would want to be looking in your host's configuration file, for the "check_command." Some typical plugins/checks used by hosts:

Code: Select all

check_icmp

check_ping

check_host_alive

[john.akash]

Hello slansing,

Thanks for the response, even I have burned lot of time to resolve this issue, I found the solution. The issue was with the AWS firewall. We need to enable ICMP response over there only after that Nagios will check whether the remote host is UP / DOWN. Thanks for the tip which you have provided me.

The solution for this issue is right here,
http://www.therealtimeweb.com/index.cfm ... n-ec2-ping

[slansing]

Oh excellent! Sometimes the equipment you are trying to monitor can be the key.