Net-SNMP on FreeBSD

1. Installation using ports
# cd /usr/ports/net-mgmt/net-snmp
# make install clean

2. List directories and files name that contain "snmpd"
# pkg_info -L net-snmp-5.4.2.1 | grep snmpd
...
/usr/local/sbin/snmpd
/usr/local/share/snmp/snmpd.conf.example
/usr/local/etc/rc.d/snmpd

3. Create snmpd.conf file from the example
# mkdir /usr/local/etc/snmp
# cp /usr/local/share/snmp/snmpd.conf.example /usr/local/etc/snmp/snmpd.conf

4. Edit the file
# vi /usr/local/etc/snmp/snmpd.conf

and modify from:
# sec.name source community
com2sec local localhost COMMUNITY
com2sec mynetwork NETWORK/24 COMMUNITY

become:
# sec.name source community
com2sec local localhost private
com2sec mynetwork 192.168.123.0/28 public

5. Modify rc configuration file
#vi /etc/rc.conf
then add this
snmpd_enable="YES"

6. Start snmp daemon
Check if port 161 active
#sockstat -4 | grep 161
---nothing displayed

Ready to start snmpd
# /usr/local/etc/rc.d/snmpd start
Starting snmpd.

# sockstat -4 | grep 161
root snmpd 16217 10 udp4 *:161 *:*

# ls /var/run | grep snmpd
snmpd.pid

Read the log file
# cat /var/log/snmpd.log

7. Is it works?
# snmpwalk -c private -v1 localhost | grep Address
# snmpwalk -c private -v2c localhost HOST-RESOURCES-MIB::hrSWRunName
# snmpwalk -c public -v1 192.168.123.1 sysDescr
SNMPv2-MIB::sysDescr.0 = STRING: OpenBSD host1.mydomain.com 4.7 GENERIC.MP#449 i386

# snmpwalk -c public -v1 192.168.123.4 sysDescr
SNMPv2-MIB::sysDescr.0 = STRING: FreeBSD host2.mydomain.com 7.0-RELEASE FreeBSD 7.0-RELEASE #0: Thu Jan 15 16:15:25 WIT 2009 root@host2.mydomain.com:/usr/src/sys/i386/compile/BINSARBSD i386

# snmpwalk -c public -v1 192.168.123.1 hrSystemUptime.0
HOST-RESOURCES-MIB::hrSystemUptime.0 = Timeticks: (15403177) 1 day, 18:47:11.77

# snmpget -c public -v1 192.168.123.4 hrSystemUptime.0
HOST-RESOURCES-MIB::hrSystemUptime.0 = Timeticks: (1598771) 4:26:27.71

# snmpget -c public -v2c 222.xxx.yyy.zzz sysUpTime.0
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (15976711) 24 day, 20:22:47.11

# snmpget -c private -v1 localhost .1.3.6.1.4.1.2021.100.6.0
# snmpwalk -c public -v1 192.168.123.1 .1.3.6.1.4.1.2021.100.6.0
# snmpstatus -c private -v2c localhost
[UDP: [0.0.0.0]->[127.0.0.1]:161]=>[FreeBSD host2.mydomain.com 7.0-RELEASE FreeBSD 7.0-RELEASE #0: Thu Jan 15 16:15:25 WIT 2009 root@host2.mydomain.com:/usr/src/sys/i386/compile/BINSARBSD i386] Up: 0:44:48.24
Interfaces: 3, Recv/Trans packets: 116458/74594 IP: 85052/74569
1 interface is down!

# snmpstatus -c public -v2c 192.168.123.1
[UDP: [0.0.0.0]->[192.168.123.1]:161]=>[OpenBSD host1.mydomain.com 4.7 GENERIC.MP#449 i386] Up: 1 day, 19:15:49.53
Interfaces: 7, Recv/Trans packets: 337656/162218 IP: 219127/159655
3 interfaces are down!

# snmptest -c public -v 1 localhost
Variable: system.sysDescr.0
Variable:
Received Get Response from UDP: [0.0.0.0]->[127.0.0.1]:161
requestid 0xCC474EF errstat 0x0 errindex 0x0
SNMPv2-MIB::sysDescr.0 = STRING: FreeBSD host2.mydomain.com 7.0-RELEASE FreeBSD 7.0-RELEASE #0: Thu Jan 15 16:15:25 WIT 2009 root@host2.mydomain.com:/usr/src/sys/i386/compile/BINSARBSD i386
Variable:

You may be interested in these OID:
# snmpget -c private -v1 localhost .1.3.6.1.2.1.1.1.0

probably these too
1.3.6.1.2.1.2.2.1.10.1
1.3.6.1.2.1.2.2.1.16.1
1.3.6.1.4.1.2021
1.3.6.1.4.1.2021.2
1.3.6.1.4.1.2021.100.6.0
1.3.6.1.4.1.2021.100.11.0

In this writing, snmpd works with SNMP version 1 and 2c and some snmpd command has been used.