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No answer from host issue

Posted: Wed Oct 03, 2018 11:13 am
by vignesha
Hello Team,

In our environment we are monitoring Switches/ Firewalls etc., we have added parameters like CPU Utilization, Hardware Status Summary, Memory usage for the network devices, so for this services we keep on getting alerts every day as "No answer from host" error and we are not facing any issue for ports monitoring.

As per my finding while running SNMPWALK command in nagios server in between am getting an error as "Timeout: No Response from xxx.xxx.xxx.xx" to destination server, so this can be reason we are facing an issue for monitoring?

so kindly help us to resolve the issue. PFA info.

Nagios Command/Output:
check_snmp_load.pl $USER1$/check_snmp_load.pl -H $HOSTADDRESS$ -C $ARG1$ -n $ARG2$ $ARG3$
[nagios@XXXXXXX ~]$ /usr/local/nagios/libexec/check_snmp_load.pl -H XXXXX -v3 -l nagios -x XXXXXX -L md5 -T cisco -w 80,70,60 -c 90,80,70 -f no global timeout defined : 5 SNMPv3 login SNMPv3 AuthNoPriv login : nagios, md5 CPU : 9 10 10 : OK | load_5_sec=9%;80;90 load_1_min=10%;70;80 load_5_min=10%;60;70

check_snmp_mem.p1 $USER1$/check_snmp_mem.pl -H $HOSTADDRESS$ -C $ARG1$ -n $ARG2$ $ARG3$
[nagios@XXXXXXX ~]$ /usr/local/nagios/libexec/check_snmp_mem.pl -H XXXXXXX -l nagios -x XXXXXXX -L md5 -I -w 80 -c 90 -f Processor:35%,IOS Process stack:70% : 36% : ; OK | ram_used=197531800;442918502;498283315;0;553648128

check-snmp-cisco $USER1$/check_snmp_environment.pl -H $HOSTADDRESS$ $ARG1$ $ARG2$
[nagios@XXXXXXX ~]$ /usr/local/nagios/libexec/check_snmp_environment.pl -H XXXXXX -l nagios -x XXXXX -L md5 -T cisco 12 Fan OK, 8 ps OK, 12 temp OK : OK

Errors:
Memory Utilization;UNKNOWN;HARD;1;ERROR opening session: No response from remote host 'xxx.xxx.xx.xx' during synchronization.
Hardware Status Summary;UNKNOWN;HARD;1;ERROR opening session: No response from remote host 'xxx.xxx.xxx.xx' during discovery.
CPU Utilization;UNKNOWN;HARD;1;No answer from host

Re: No answer from host issue

Posted: Wed Oct 03, 2018 3:29 pm
by ssax
As per my finding while running SNMPWALK command in nagios server in between am getting an error as "Timeout: No Response from xxx.xxx.xxx.xx" to destination server, so this can be reason we are facing an issue for monitoring?
If the snmpwalk command is not responding then it's the remote device that is having issues, does this happen at the same time every day? Could it be related to backups or another high IO/load process occurring on the remote devices?

To limit the amount of timeout errors you get, all 3 of the plugins you listed have a default timeout of like 5 seconds, please edit your commands and add a -t 30 to them to increase the timeout from the default, since many SNMP queries take longer than 5 seconds this should alleviate some of the ones that take longer than 5 seconds giving the timeout error.

If the remote device isn't responding to the snmpwalk though there's nothing we can really do from the XI side other than increasing the timeout of the commands. If the SNMP daemon on the remote device isn't responding in time or isn't responding at all you'll need to look at the device to see what is occuring at that time that may be impacting it.

Re: No answer from host issue

Posted: Wed Oct 10, 2018 3:13 am
by vignesha
ssax wrote:
As per my finding while running SNMPWALK command in nagios server in between am getting an error as "Timeout: No Response from xxx.xxx.xxx.xx" to destination server, so this can be reason we are facing an issue for monitoring?
If the snmpwalk command is not responding then it's the remote device that is having issues, does this happen at the same time every day? Could it be related to backups or another high IO/load process occurring on the remote devices?

To limit the amount of timeout errors you get, all 3 of the plugins you listed have a default timeout of like 5 seconds, please edit your commands and add a -t 30 to them to increase the timeout from the default, since many SNMP queries take longer than 5 seconds this should alleviate some of the ones that take longer than 5 seconds giving the timeout error.

If the remote device isn't responding to the snmpwalk though there's nothing we can really do from the XI side other than increasing the timeout of the commands. If the SNMP daemon on the remote device isn't responding in time or isn't responding at all you'll need to look at the device to see what is occuring at that time that may be impacting it.
Hello Ssax,

We are facing this issue daily, so as per your suggestion we increased timeout as -t 30 issue resolved now.
Thanks for support.

Re: No answer from host issue

Posted: Wed Oct 10, 2018 8:08 am
by scottwilkerson
vignesha wrote:Hello Ssax,

We are facing this issue daily, so as per your suggestion we increased timeout as -t 30 issue resolved now.
Thanks for support.
Glad to hear it is resolved!

Locking thread.