Configuring SNMP Support

Keepalived provides an SNMP subsystem that can gather various metrics about the VRRP stack and the health checker system. The keepalived MIB is in the doc directory of the project. The base SNMP OID for the MIB is .1.3.6.1.4.1.9586.100.5, which is hosted under the Debian OID space assigned by IANA.

Prerequisites *********

Install the SNMP protocol tools and libraries onto your system. This requires the installation of a few packages:

yum install net-snmp net-snmp-utils net-snmp-libs

Once SNMP has been installed on your system, configure keepalived with SNMP support. When compiling keepalived, add the --enable-snmp configure option. For example:

./configure --enable-snmp

During the configure step of the compiling process, you will get a configuration summary before building with make. For example, you may see similar output on a CentOS 6 machine:

./configure --prefix=/usr/local/keepalived-1.2.15 --enable-snmp
Keepalived configuration
------------------------
Keepalived version       : 1.2.15
Compiler                 : gcc
Compiler flags           : -g -O2 -I/usr/include/libnl3
Extra Lib                : -Wl,-z,relro -Wl,-z,now -L/usr/lib64
-lnetsnmpagent -lnetsnmphelpers -lnetsnmpmibs -lnetsnmp -Wl,-E
-Wl,-rpath,/usr/lib64/perl5/CORE -lssl -lcrypto -lcrypt  -lnl-genl-3 -lnl-3
Use IPVS Framework       : Yes
IPVS sync daemon support : Yes
IPVS use libnl           : Yes
fwmark socket support    : Yes
Use VRRP Framework       : Yes
Use VRRP VMAC            : Yes
SNMP support             : Yes
SHA1 support             : No
Use Debug flags          : No

Notice the Extra Lib section of the configuration summary. It lists various library flags that gcc will use to build keepalived, several of which have to do with SNMP.

Configuring Support

Enable SNMP AgentX support by including the following line in the SNMP daemon configuration file, typically /etc/snmp/snmpd.conf if you installed via RPMs on a CentOS machine:

master agentx

Note

Be sure to reload or restart the SNMP service for the configuration change to take effect.

Adding the MIB

You can query keepalived SNMP managed objects by using the OID. For example:

snmpwalk -v2c -c public localhost .1.3.6.1.4.1.9586.100.5.1.1.0
SNMPv2-SMI::enterprises.9586.100.5.1.1.0 = STRING: "Keepalived v1.2.15 (01/10,2015)"

Alternatively, with the keepalived MIB, you can query using the MIB available from the project. First, copy the MIB to the system’s global MIB directory or to the user’s local MIB directory:

cp /usr/local/src/keepalived-1.2.15/doc/KEEPALIVED-MIB /usr/share/snmp/mibs

or:

cp /usr/local/src/keepalived-1.2.15/doc/KEEPALIVED-MIB ~/.snmp/mibs

The SNMP daemon will check both directories for the existence of the MIB. Once the MIB is in place, the SNMP query can look as follows:

snmpwalk -v2c -c public localhost KEEPALIVED-MIB::version
KEEPALIVED-MIB::version.0 = STRING: Keepalived v1.2.15 (01/10,2015)

MIB Overview

There are four main sections to the keepalived MIB:

• global
• vrrp
• check
• conformance

Global

The global section includes objects that contain information about the keepalived instance such as version, router ID and administrative email addresses.

VRRP

The VRRP section includes objects that contain information about each configured VRRP instance. Within each instance, there are objects that include instance name, current state, and virtual IP addresses.

Check

The Check section includes objects that contain information about each configured virtual server. It includes server tables for virtual and real servers and also configured load balancing algorithms, load balancing method, protocol, status, real and virtual server network connection statistics.

Conformance

Todo

do conformance

Note

Use a MIB browser, such as mbrowse, to see what managed objects are available to query for monitoring the health of your LVS servers.