SNMP traps not working

[eshwarharsha]

Hi,

We have installed Nagios XI recently and currently doing our POC. We have used the inbuilt wizards to perform basic monitoring. Now, when I try to use "SNMP Trap" wizard so that I can receive the traps from our Cisco devices, it doesn't work. I had gone through the documentation provided by Nagios and it says I should see the logs at "/var/log/snmptt/snmptt.log" (I cannot see the snmpttunknown.log file as well). The only file I can find in snmptt folder is "snmpttsystem.log".

I had also used these commands for automated installation of SNMP:
cd /tmp
wget https://assets.nagios.com/downloads/nag ... p-setup.sh
sh ./NagiosXI-SNMPTrap-setup.sh

I had also tried adding snmp trap service for localhost and using the command "snmptrap -v 2c -c public 127.0.0.1 '' linkUp ifDescr s eth0 ifAdminStatus i 1 ifOperStatus i 1" from CLI. The service status still says "Waiting for trap...".

When I do ps aux on the server where Nagios XI is installed, I get this output:
[root@nagiost1 snmptt]# ps -aux | grep -i snmp
root 6985 0.0 0.0 229736 7944 ? Ss May04 0:05 /usr/sbin/snmptrapd -Lsd -f
root 27154 0.0 0.1 240124 10904 ? Ss May04 1:41 /usr/sbin/snmpd -LS0-6d -f
root 24591 0.0 0.0 112708 996 pts/0 S+ 10:22 0:00 grep --color=auto -i snmp

I am guessing it's missing snmptt service? Any ideas how this problem can be solved?

Thanks in advance!

[cdienger]

A commonly missed step is the need to update the snmptt.conf file as described in https://support.nagios.com/kb/article.php?id=559. Run through this and run the snmptrap command again and check /usr/local/nagios/var/nagios.log for entries as well as the status in the web UI.

Traps coming from other machines may be getting dropped due to iptables. Check to make sure an entry like the one below is seen when you run "iptables -L INPUT":

ACCEPT udp -- anywhere anywhere state NEW udp dpt:snmptrap