How to Install and Configure SNMP in CentOS
To Install and Configure SNMP in CentOS
SNMP stands for Simple Network Management Protocol. It is an internet standard protocol that can retrieve the operational statistics of the routers and firewalls remotely. This article explains the installation and configuration process of the SNMP in CentOS.
Installation of SNMP
Utilize the ' yum' command to install SNMP packages.
[root@linuxhelp ~]# yum -y install net-snmp net-snmp-utils
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: mirror.fibergrid.in
* extras: mirror.fibergrid.in
* updates: mirror.fibergrid.in
Resolving Dependencies
--> Running transaction check
---> Package net-snmp.x86_64 1:5.7.2-24.el7_2.1 will be installed
--> Processing Dependency: net-snmp-libs = 1:5.7.2-24.el7_2.1 for package: 1:net-snmp-5.7.2-24.el7_2.1.x86_64
--> Processing Dependency: net-snmp-agent-libs = 1:5.7.2-24.el7_2.1 for package: 1:net-snmp-5.7.2-24.el7_2.1.x86_64
--> Processing Dependency: libnetsnmptrapd.so.31()(64bit) for package: 1:net-snmp-5.7.2-24.el7_2.1.x86_64
--> Processing Dependency: libnetsnmpmibs.so.31()(64bit) for package: 1:net-snmp-5.7.2-24.el7_2.1.x86_64
.
.
Installed:
net-snmp.x86_64 1:5.7.2-24.el7_2.1
Dependency Installed:
net-snmp-agent-libs.x86_64 1:5.7.2-24.el7_2.1
Updated:
net-snmp-utils.x86_64 1:5.7.2-24.el7_2.1
Dependency Updated:
net-snmp-libs.x86_64 1:5.7.2-24.el7_2.1
Complete!
Once the SNMP packages is installed, add the basic configuration for SNMP.
[root@linuxhelp ~]# mv /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.orig
Move the SNMP configuration to an alternate location, /etc/snmp/snmpd.conf.orig.
Now its time to create a new file and add the following lines as shown below,
[root@linuxhelp ~]# vim /etc/snmp/snmpd.conf
# Map ' idv90we3rnov90wer' community to the ' ConfigUser'
# Map ' 209ijvfwer0df92jd' community to the ' AllUser'
# sec.name source community
com2sec ConfigUser default idv90we3rnov90wer
com2sec AllUser default 209ijvfwer0df92jd
# Map ' ConfigUser' to ' ConfigGroup' for SNMP Version 2c
# Map ' AllUser' to ' AllGroup' for SNMP Version 2c
# sec.model sec.name
group ConfigGroup v2c ConfigUser
group AllGroup v2c AllUser
# Define ' SystemView' , which includes everything under .1.3.6.1.2.1.1 (or .1.3.6.1.2.1.25.1)
# Define ' AllView' , which includes everything under .1
# incl/excl subtree
view SystemView included .1.3.6.1.2.1.1
view SystemView included .1.3.6.1.2.1.25.1.1
view AllView included .1
# Give ' ConfigGroup' read access to objects in the view ' SystemView'
# Give ' AllGroup' read access to objects in the view ' AllView'
# context model level prefix read write notify
access ConfigGroup " " any noauth exact SystemView none none
access AllGroup " " any noauth exact AllView none none
Save and exit the file.
Restart the SNMP to take effect.
[root@linuxhelp ~]# service snmpd restart
Redirecting to /bin/systemctl restart snmpd.service
Configure SNMP to start when the server boots:
[root@linuxhelp ~]# chkconfig snmpd on
Note: Forwarding request to ' systemctl enable snmpd.service' .
ln -s ' /usr/lib/systemd/system/snmpd.service' ' /etc/systemd/system/multi-user.target.wants/snmpd.service'
Try out the following two commands to test the SNMP configuration file.
[root@linuxhelp ~]# snmpwalk -v 2c -c idv90we3rnov90wer -O e 127.0.0.1 SNMPv2-MIB::sysDescr.0 = STRING: Linux linuxhelp 3.10.0-123.el7.x86_64 #1 SMP Mon Jun 30 12:09:22 UTC 2014 x86_64 SNMPv2-MIB::sysObjectID.0 = OID: NET-SNMP-MIB::netSnmpAgentOIDs.10 DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (19818) 0:03:18.18 SNMPv2-MIB::sysContact.0 = STRING: root@localhost SNMPv2-MIB::sysName.0 = STRING: linuxhelp SNMPv2-MIB::sysLocation.0 = STRING: Unknown SNMPv2-MIB::sysORLastChange.0 = Timeticks: (5) 0:00:00.05 SNMPv2-MIB::sysORID.1 = OID: SNMP-MPD-MIB::snmpMPDCompliance SNMPv2-MIB::sysORID.2 = OID: SNMP-USER-BASED-SM-MIB::usmMIBCompliance SNMPv2-MIB::sysORID.3 = OID: SNMP-FRAMEWORK-MIB::snmpFrameworkMIBCompliance SNMPv2-MIB::sysORID.4 = OID: SNMPv2-MIB::snmpMIB . . . SNMPv2-MIB::sysORUpTime.9 = Timeticks: (5) 0:00:00.05 SNMPv2-MIB::sysORUpTime.10 = Timeticks: (5) 0:00:00.05 HOST-RESOURCES-MIB::hrSystemUptime.0 = Timeticks: (178268) 0:29:42.68 HOST-RESOURCES-MIB::hrSystemUptime.0 = No more variables left in this MIB View (It is past the end of the MIB tree) [root@linuxhelp ~]# snmpwalk -v 2c -c 209ijvfwer0df92jd -O e 127.0.0.1 SNMPv2-MIB::sysDescr.0 = STRING: Linux linuxhelp 3.10.0-123.el7.x86_64 #1 SMP Mon Jun 30 12:09:22 UTC 2014 x86_64 SNMPv2-MIB::sysObjectID.0 = OID: NET-SNMP-MIB::netSnmpAgentOIDs.10 DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (25414) 0:04:14.14 SNMPv2-MIB::sysContact.0 = STRING: root@localhost SNMPv2-MIB::sysName.0 = STRING: linuxhelp SNMPv2-MIB::sysLocation.0 = STRING: Unknown SNMPv2-MIB::sysORLastChange.0 = Timeticks: (5) 0:00:00.05 SNMPv2-MIB::sysORID.1 = OID: SNMP-MPD-MIB::snmpMPDCompliance SNMPv2-MIB::sysORID.2 = OID: SNMP-USER-BASED-SM-MIB::usmMIBCompliance SNMPv2-MIB::sysORID.3 = OID: SNMP-FRAMEWORK-MIB::snmpFrameworkMIBCompliance SNMPv2-MIB::sysORID.4 = OID: SNMPv2-MIB::snmpMIB SNMPv2-MIB::sysORID.5 = OID: TCP-MIB::tcpMIB . . . SCTP-MIB::sctpRtoInitial.0 = Gauge32: 0 milliseconds SCTP-MIB::sctpMaxAssocs.0 = INTEGER: 0 SCTP-MIB::sctpValCookieLife.0 = Gauge32: 0 milliseconds SCTP-MIB::sctpMaxInitRetr.0 = Gauge32: 0
The result for your first command is about 33 lines and contain some basic system information. But the second command will display the information about the system and likely be thousands of lines.
davshakaryan
Jul 13 2018
Thanks
Q
What protocols are supported for SNMP?
A
SNMP supports all three current versions of SNMP (v1, v2c, and v3), over both UDP and TCP transports.
Q
How do I remove a MIB from the agent?
A
Follow these steps mentioned below to remove MIB
re-run 'configure' to exclude the given MIB module(s) from the build configuration, then recompile and reinstall:
# ./configure --with-out-mib-modules=path/to/unwanted
# make
# make install
re-run 'configure' to exclude the given MIB module(s) from the build configuration, then recompile and reinstall:
# ./configure --with-out-mib-modules=path/to/unwanted
# make
# make install
Q
Need to configure SNMP from the host, not from PFsense?
A
For generating SNMP from the host
You need a firewall rule on WAN that passes the traffic to the inside address and port.
That is generated automatically by default.
You need a firewall rule on WAN that passes the traffic to the inside address and port.
That is generated automatically by default.
Q
Have you tried to run ie 'tcpdump' with appropriate options on both server and client to see what happens when the SNMP-request is run?
A
SNMP is UDP (sessionless) ==> is a connection always possible and given during the whole request.
Q
How to make MIB file of SNMP protocol in linux?
A
You can download default MIBs from websites and upload them in Linux for SNMP Protocols.