Let’s look into other interfaces. Sometimes you will need to monitor something that doesn’t work with an agent: printer, router, etc. SNMP can help you with that.
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First, you will need is to find the variable’s OID (Object Identifier) the numeric code that will help the server to request the specific things we will monitor.
To do so you can look it up in the device's manual or discover it with snmpwalk utility or use any MIB browser you like. For this article we will look into using snmpwalk.

snmpwalk

Let's look into getting OIDs with snmpwalk.
Install the SNMP package: you'll need to install the SNMP package. On Debian-based systems, you can install it with:

On Red Hat-based systems, you can use:

On Windows system, you can use the Net-SNMP package for Windows, which is available at Net-SNMP website (https://www.net-snmp.org/download.html).

Check the IP address or hostname of the device you want to query, as well as the SNMP version this device supports (usually SNMPv1 or SNMPv2c).

You'll also need to find out the SNMP community for the device. This works like a password that allows to access the SNMP data on this host. You should be able to find this in the device's documentation or configuration, the usual default option is ‘public’.

If you learned the OID you need from manual, run the snmpwalk command to check if everything's fine. The basic syntax for snmpwalk is the same on Windows as on Linux or Unix:

for example

Getting variable value with snmpwalk

Here, the OID .1.3.6.1.2.1.1.5.0 specifies the hostname, and the snmpwalk command will return the MIB name along with the current value and the variable type.

To discover an OID with snmpwalk you could run it without an OID or MIB name to search the one you interested in manually.

Getting all of the host's OIDs

After finding out its name run the same command adding - On

Getting OID number

Note that some variables have more than one port the last number in OID shows this port.

Hosts

Next, we will need to add a host with an SNMP interface configured and enter your device’s IP, SNMP version, and SNMP community. SNMP templates can be handy, but compatibility is not granted. Otherwise it’s a usual host creation.

Adding SNMP interface to a host

Items

The only thing left is to create an SNMP item: Go to Configuration > Hosts and click on the device you want to monitor. Go to the Items tab and click on the "Create item" button. Fill in the necessary information: item name, type (for our example, SNMPv2 agent), information type, and OID. Fill the Key line with OID number.

Creating Item

Press test to see if it works.

Testing the item

Once everything is set up, you should start seeing data from the device in Zabbix. You can use Zabbix's graphs, triggers, and other features to monitor the device and be alerted if there are any issues.

Conclusion

SNMP is a simple way to monitor devices that can’t run an agent — routers, switches, printers, UPS, and other network gear. In this guide, you used snmpwalk to discover the right OIDs (or validate them from documentation), then created a Zabbix host with an SNMP interface and added SNMP items to start collecting metrics.
To keep monitoring reliable and secure, prefer SNMPv3 where possible, limit access to UDP/161 by allowlist/firewall, and test OIDs with snmpget/snmpwalk before building dashboards and triggers. Once the data is flowing, you can reuse it across graphs, triggers, and templates to scale monitoring to dozens of devices with minimal effort.

FAQ

• 1) What’s the difference between an OID and a MIB?
  An OID is the numeric path (for example, .1.3.6.1.2.1.1.5.0). A MIB is the “dictionary” that maps human-readable names (like sysName.0) to those numeric OIDs.
• 2) Should I use SNMPv2c or SNMPv3?
  Use SNMPv3 in production: it supports authentication and encryption. SNMPv2c is easier to start with, but the community string is sent in plaintext and should only be used in controlled networks.
• 3) Why does snmpwalk return “Timeout: No Response”?
  Most common causes:
  SNMP is disabled on the device, Wrong IP/hostname, version, or credentials, Firewall/ACL blocking UDP/161, Device only allows SNMP from specific source IPs
• 4) What does the last number in sysName.0 mean?
  That last part is usually the instance/index. For many “single-value” system metrics it’s .0. For tables (like interfaces), the index changes per row (for example, interface 1, 2, 3, etc.).
• 5) Zabbix item “unsupported” — what should I check first?
  The SNMP OID field is correct (not accidentally placed in Key)
  Zabbix host has the SNMP interface configured
  Device responds to snmpget/snmpwalk from the Zabbix server
  Correct SNMP version (v2c vs v3) and credentials
• 6) When should I use snmpget instead of snmpwalk?
  Use snmpget for a single OID value (faster and cleaner). Use snmpwalk to explore a whole branch or discover table indexes.
• 7) How do I find the interface index for traffic counters?
  Walk the interface name table (usually ifDescr / ifName) to map indexes to ports, then use that index with counters like ifInOctets / ifOutOctets.
• 8) Do I really need MIB files installed?
  Not required. Without MIBs you’ll mostly see numeric OIDs, but everything still works. MIBs just make output and configuration more readable.
• 9) Is it OK to scan all OIDs with snmpwalk without specifying a subtree?
  Not recommended. It can generate huge output and load the device. Start with relevant subtrees (system/interfaces/host-resources) and filter.
• 10) How do I make SNMP monitoring more secure?
  Prefer SNMPv3 authPriv
  Allowlist only the Zabbix server IP
  Block public access to UDP/161
  Avoid default community strings (public, private)