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I built the following Zabbix template to monitor small routers, with just two interfaces (WAN and LAN), which have been deployed as CPE for some customers.

What I needed was only interfaces monitoring, such as traffic, packets, status, but I needed to configure it for many etherogeneous devices, that means different SNMP indexing and naming.

I decided to build a small SNMP-based template using dynamic parameters and host macros.

Each template’s item has an SNMP OID value containing a macro reference:

Description: LAN - Description
Type: SNMPv2 agent
SNMP OID: .1.3.6.1.2.1.2.2.1.2.{$LAN_IF_IDX}
Key: ifDescr-LAN

Description: LAN - In Octets
Type: SNMPv2 agent
SNMP OID: .1.3.6.1.2.1.2.2.1.10.{$LAN_IF_IDX}
Key: ifInOctets-LAN

Description: WAN - Description
Type: SNMPv2 agent
SNMP OID: .1.3.6.1.2.1.2.2.1.2.{$WAN_IF_IDX}
Key: ifDescr-WAN

...

On each host you apply this template to you need to add two macros, {$LAN_IF_IDX} and {$WAN_IF_IDX}, containing the value of the LAN and WAN interface SNMP index:

In order to understand which value to use in the macro you can “ask it” to your router or run a snmpwalk on it:

CiscoRouter#show snmp mib ifmib ifindex FastEthernet 0/0
Interface = FastEthernet0/0, Ifindex = 1

root@NMS:~# snmpwalk -v 2c -c public 10.0.0.1 .1.3.6.1.2.1.2.2.1.2
iso.3.6.1.2.1.2.2.1.2.1 = STRING: "FastEthernet0/0"
iso.3.6.1.2.1.2.2.1.2.2 = STRING: "FastEthernet0/1"
iso.3.6.1.2.1.2.2.1.2.3 = STRING: "VoIP-Null0"
iso.3.6.1.2.1.2.2.1.2.4 = STRING: "Null0"
iso.3.6.1.2.1.2.2.1.2.5 = STRING: "Loopback1"

The template includes interfaces description, status, traffic (in bps and packets per second), a trigger to detect status transition and graphs.

You can find the Zabbix Template_Lightweight_Dynamic_SNMPv2_Router here; instructions about importing the template can be found on the Zabbix documentation web site.

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Pier Carlo Chiodi

Italian, born in 1980, I started working in the IT/telecommunications industry in the late '90s; I'm now a system and network engineer with a deep knowledge of the global Internet and its core architectures, and a strong focus on network automation.

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