Feb 102016
 

I recently got my hands on a Linksys SRW2048 switch to use as the core of my home network. The main reason why I wanted this was for VLANs so I could start experimenting with them in my homelab, but as a bonus, the switch supports SNMP which means that I can use my Zabbix instance to monitor the stats on the switch.

The SNMP configuration on these switches are straightforward as they have a WebGUI to use to configure the community strings. Once SNMP was setup though, I found that Zabbix could not monitor the switch correctly using the out of the box SNMP template.
After a snmpwalk, I quickly found out the reason why.

IF-MIB::ifDescr.1 = STRING: Ethernet Interface
IF-MIB::ifDescr.2 = STRING: Ethernet Interface
IF-MIB::ifDescr.3 = STRING: Ethernet Interface
IF-MIB::ifDescr.4 = STRING: Ethernet Interface
**SNIP**
IF-MIB::ifDescr.45 = STRING: Ethernet Interface
IF-MIB::ifDescr.46 = STRING: Ethernet Interface
IF-MIB::ifDescr.47 = STRING: Ethernet Interface
IF-MIB::ifDescr.48 = STRING: Ethernet Interface

All 48 ports on the switch had the same ifDescr, which is what Zabbix uses to distinguish interfaces from each other when using the default SNMP Interfaces template.

The solution to this issue was to create my own SNMP LLD rules for the switch so that it would use the SNMP index as well as the ifDescr to distinguish between interfaces.

All the rules are the same as the default SNMP Interface LLD, except that I needed to add the {#SNMPINDEX} macro into the key, and $2 to the item name.

This is what the 'Admin status of Interface' item prototype looks like

This is what the ‘Admin status of Interface’ item prototype looks like

Applying these new rules on the Linksys resulted in the interfaces being named properly as you can see in this screenshot:

Properly Named Interfaces

Properly Named Interfaces

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  2 Responses to “Monitoring Linksys SRW2048 with Zabbix”

  1. What do you mean by LLD?

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