SNMPTT (SNMP Trap Translator) interacts with snmptrapd to receive traps and process them into Nagios by matching the IP of the trapping host to a host in Nagios and changing a passive check in Nagios to alert someone.
In the below guide:
[APC-UPS] –>send traps to–> [SNMPTRAPD –> SNMPTT –> NAGIOS]

Here’s a simple guide, adapted and made much more cut and dry (and a little more simpler) from the guide found here.
We use Nagios 3.20, SNMPTT 1.3beta2, Debian Lenny (5)
As usual, your feedback will mean a lot to us. Thanks!
Sanjay.
Download some pre-reqs
=======================
Main component is SNMP (and some snmp tools) so do this at the CLI
apt-get install snmp snmpd libsnmp-dev
SNMPTT setup starts
===================
1) apt-get install unzip
2) cd /usr/src
3) wget http://search.cpan.org/CPAN/authors/id/C/CH/CHORNY/Text-ParseWords-3.27.zip
4) unzip Text-ParseWords-3.27.zip
5) cd Text-ParseWords-3.27
6) perl Makefile.PL
7) make test
8) make install
9) perl -MCPAN -e shell
At the Perl CLI
install YAML
install Getopt::Long
install Config::IniFiles
install Time::HiRes
install Sys::Hostname
install Text::Balanced
install Sys::Syslog
install DBI
install DBD::mysql
install Crypt::DES
install Digest::MD5
install Digest::SHA1
install Digest::HMAC
install Net::SNMP
Download, install and configure snmptt (the magician)
=====================================================
10) cd /usr/src
11) wget http://downloads.sourceforge.net/project/snmptt/snmptt/snmptt_1.3beta2/snmptt_1.3beta2.tgz?use_mirror=nchc
12) tar -zxvf snmptt_1.3beta2.tgz
13) cd snmptt_1.3beta2
14) cp snmptthandler /usr/sbin
15) cp snmptt /usr/sbin
16) cp snmpttconvert /usr/sbin
17) cp snmpttconvertmib /usr/sbin
Configure snmptrapd to not log but send them to snmptt
======================================================
18) nano /etc/snmp/snmptrapd.conf
19) Enter the following lines in there
traphandle default /usr/sbin/snmptt
disableAuthorization yes
donotlogtraps yes
Configure and enable the snmptrapd as a service
===============================================
20a) nano /etc/default/snmpd and /etc/init.d/snmpd
TRAPDRUN=yes
TRAPDOPTS=’-On -Lsd -p /var/run/snmptrapd.pid’
20b) /etc/init.d/snmpd start
21) netstat -an | grep “162”
>> Should see output
22) cd usr/src/snmptt_1.3beta2
23) cp snmptt.ini /etc/snmp
24) nano /etc/snmp/snmptt.ini, look for and change the following settings
net_snmp_perl_enable = 1
dns_enable=1
25) cd /usr/src/nagios-plugins-1.4.13/
26) mkdir /usr/local/nagios/libexec/eventhandlers
27) cd /usr/local/nagios/libexec/eventhandlers
28) wget
29) chmod +x submit_check_result
TESTING – Create sample to test
===============================
30) cd /usr/share/snmp/mibs
31) wget
32) snmpttconvertmib –in=PowerNet-MIB.mib –out=/etc/snmp/snmptt.conf.apcpower –exec=’/usr/local/nagios/libexec/eventhandlers/submit_check_result $r TRAP 1′
Here, the line above, you can change TRAP to any name as long as it matches the Service name in Nagios and 1 is the alert type, 0=OK, 1=WARNING, 2=CRITICAL etc..
33) nano /etc/snmp/snmptt.ini
add the /etc/snmp/snmptt.conf.cpqpower in [TrapFiles], comment out snmptt.conf
Example: Here we added /etc/snmp/snmptt.conf.apcpower based on the snmpttconvertmib outputfile like above
[TrapFiles]
snmptt_conf_files = <<END
/etc/snmp/snmptt.conf.apcpower
END
Enable log rotation
=======================
34) nano /etc/logrotate.conf
This is for log rotation. Add the following line at the end
/var/log/snmp/snmptt.log /var/log/snmp/snmpttunknown.log
{
missingok
}
35) mkdir /var/log/snmptt
36) touch /var/log/snmptt/snmptt.log
37) touch /var/log/snmptt/snmpttunknown.log
Configuring hosts file
=======================
Traps send IP not name, so we must configure /etc/hosts to add the name and ip of the device sending traps to us
38) nano /etc/hosts
Add the following as sample
192.168.1.11 sanjaypc

> Important! This name will be the same as your hosts.cfg file in nagios that will receive the traps
Send a sample trap: – Load the same MIBs into a program like ireasoning and send a trap to your nagios IP
=======================================================
39) tail -f /var/log/snmptt/snmptt.log
Sun Nov 8 09:09:11 2009 .1.3.6.1.4.1.318.0.5 WARNING “Status Events” 192.168.157.1 – APC UPS: On battery: The UPS has switched to battery backup power.
40) tail -f /var/log/messages — Output (after configuring Nagios settings below – or at least have a host/service defined that matches sanjaypc and TRAP)
Nov 8 09:09:20 server1 nagios: PASSIVE SERVICE CHECK: sanjaypc;TRAP;1;APC UPS: On battery: The UPS has switched to battery backup power.
Configuring Nagios- Sample definitions
=====================================
trap-service template
=====================================
define service{
name generic-service
register 0
check_period 24×7
max_check_attempts 3
normal_check_interval 15
retry_check_interval 5
active_checks_enabled 1
passive_checks_enabled 0
parallelize_check 1
obsess_over_service 0
check_freshness 0
event_handler_enabled 0
flap_detection_enabled 0
process_perf_data 1
retain_status_information 1
retain_nonstatus_information 1
notification_interval 60
notification_period 24×7
notification_options w,u,c,r
notifications_enabled 1
}
define service{
name trap-service
use generic-service
register 0
service_description TRAP
is_volatile 1
check_command check-host-alive
max_check_attempts 1
normal_check_interval 1
retry_check_interval 1
passive_checks_enabled 1
check_period none
notification_interval 0
contact_groups admins
}
Create service to host – NOTE: Hostname must match to /etc/hosts definition we created earlier
==================================================
define service{
host_name sanjaypc
use trap-service
contact_groups admins
}
41) Restart nagios
42) Send a trap again and check Nagios website, it should turn yellow [WARNING] and a notificaiton sent out