6 min
What is SNMP v3 and what is it used for? Read on to find out!
Simple Network Management Protocol version 3, or SNMPv3, is a network monitoring protocol – unlike other communication-centric standards, it focuses on device behaviors and control. But how does it work? Here’s what we’re going to cover in this article.
How MSPs and SysAdmins Use SNMP for More Effective Networking
SNMP standardizes how managed device information gets aggregated and stored by network monitoring tools. For instance, your admin dashboard may leverage a subset of the protocol, like SNMP polling, to query the attached device for performance data, such as memory usage and bandwidth consumption history. Learn all about what SNMP is and how it works.
SNMP has some security features, but it’s neither a security-specific standard nor a complete network health solution. Instead, it’s more common to use these alongside other techniques.
For instance, imagine you decide to map out all of the devices on your network. You can use SNMP to get data from different routers and switches to build a pretty good picture of where the central network nodes are and what’s connected to them.
In SNMP, data flows both ways – from the managing devices to those under management and vice-versa – albeit with some performance- and security-driven restrictions. You can even use SNMP to watch for problems by setting up admin alerts and programming custom message routing for your predefined events!
Sounds great, huh? Bet you feel like you’re ready to probe the depths of any infrastructure! Sadly, it’s not quite that simple.
While SNMP can do all these things and more, it’s not an app alone – just a protocol and some shell utilities. Unless they genuinely love torturing themselves on the command line, most admins and MSPs use some form of higher-level framework to manage their SNMP activities and flows.
Pro tip: If all of this seems complicated, check out Domotz network monitoring software to help manage SNMP for you.
What is SNMP v3? Use Cases
For now, here are some excellent use cases you might encounter in the real world:
- Monitoring network devices for power consumption and temperature to make a data center more efficient,
- Managing server performance to inform load-balancing strategies,
- Keeping an eye on storage device capacity or device failures in a database, and
- Watching running services and applications to see the bigger picture – not just what their logs tell you after the fact but how they use resources in real-time.
An Overview of SNMPv3
SNMPv3 is the latest version of an Internet Standard from the early days of the web. The protocol has matured significantly with its version-one RFC released in the early 1990s.
At the heart of SNMP lies the distinction between managers, managed devices, agents, and network management stations:
- Managed devices are the connected devices you want to administer, such as printers, computers, phones, fleet vehicles, or IoT hardware. Managers are any devices that do the tracking, using the protocol to communicate with other managers and managed devices.
- Agents are software processes that run on a network device. They provide information to the local SNMP manager’s network management station.
- Network management station (NMS) software task runners execute monitoring and control applications on the manager machines. They also receive data from the agents and send out your control instructions.
Another important SNMP concept is the management information base or MIB. In short, agents respond to queries about the state of the managed system, and to make such querying easy, they expose variables organized as per the MIB. The result is that you can uniquely look up and hierarchically modify specific parameters.
What Makes SNMPv3 Special? The Features, Architecture, and Mechanisms
SNMPv3 differs from its ancestors in a few key ways. Although it didn’t change the fundamental workings of the protocol as defined above, it implemented some critical changes that many users had long been craving. For instance, it:
- Uses message integrity checks to be sure that messages reach their destination intact – without having been altered in transit,
- Protects the privacy of message contents from snoopers by using packet-level encryption,
- Supports configuring agents to respond only to requests from authorized managers, and
- SNMP v3 also includes upgrades to the cleartext community-group-based password standards with secure authentication.
Another important distinction is how the latest SNMP edition understands messaging. In addition to the security-minded features like encryption and authentication, this version defines:
- Notification originators are responsible for sending SNMPv3 notifications to management stations, and
- Proxy forwarders relay SNMPv3 messages from notification originators to management stations.
These roles make configuring advanced routing and monitoring frameworks typical of MSPs and corporate infrastructures easier. When combined with SNMPv3’s support for more secure remote configuration and administration, originators and forwarders can build highly robust network health monitoring systems.
SNMPv3 Communication Mechanisms
We’ve already hinted at this a few times, but all communication between devices using the SNMP protocol happens in the form of standardized messages handled via known UDP ports. These messages come in a few different synchronous and asynchronous flavors classified by their purpose, direction of flow, and payload contents.
SNMPv3 added concepts known as users, groups, and views, broadening the general security focus to see beyond individual messages and account for interaction patterns. As a result, an authorized admin can define their user-based security model (USM) regulating which types of data access are allowed for different groups of users:
- NoAuthNoPriv: This access type does not require authentication or privacy. It’s the lowest level of security. It would be best to use it only when safety isn’t a concern.
- AuthNoPriv: This security level requires authentication but not privacy. You’ll typically use it when the transmitted data isn’t sensitive.
- AuthPriv: This security level requires both authentication and privacy. It is the highest level of security and is appropriate for most situations involving sensitive data transmissions, although some admins enable it by default to be safe.
Why is USM Such a Powerful Game-changer for Network Management?
One of the big problems with earlier SNMP versions was that they were lacking in the security department. At the same time, the protocol retained popularity for its ease of use and extremely low overhead, a combination of features that few admins would willingly relinquish!
USM helps push network owners towards a better state without forcing them to relinquish total control. They can still gain valuable insights without bogging things down, which is vital in modern networks that increasingly host high numbers of devices and users, such as the linked manufacturing machines on a factory floor or the IP phones connected to a government office PBX. Even better, they’re not as susceptible to the IP spoofing attacks that plagued the other SNMP versions.
Does SNMPv3 Have Weaknesses?
One of the main shortcomings of SNMPv3 is that it is not entirely compatible with SNMPv2. It supports more message types and commands, for example, not to mention all of the added security upgrades.
If you’re trying to upgrade from old systems, expect to need to do extra work to keep your old monitoring framework running. These updates may require additional work for routers and switches that only get so many firmware updates before the end of their manufacturer-supported lifetimes.
Another challenge is that SNMPv3 requires a lot of configuration. Those fancy USMs and routing behaviors aren’t just going to define themselves, and it doesn’t help that on-demand MIB hierarchies aren’t always the easiest to understand. It’s critical to work with a tool that eases the journey by helping you organize policies, notifications, and actions sensibly, especially if you plan on network growth or heavy usage.
Good management dashboards let you enact security policies from a unified command center, minimizing the odds of someone making a mistake that exposes vital information. They allow you to view the data you collect from commands and notifications in an organized fashion that reveals insights you’d miss otherwise.
SNMPv3 is a definite improvement on the standards that came before it. This version of the protocol is your only choice for implementing comprehensive monitoring practices as professionally and securely as possible. When it comes to public-facing networks or sensitive organizational infrastructures, it’s the only option. You will, however, need to have suitable systems in place if you want to make the most of its power.
Tying SNMP v3 Together
MSPs pack their toolbox with helpers to keep networks healthy.
SNMPv3 is just one of many such tools, but its versatility, security focus, and technical maturity make the protocol a handy answer to many of the problems admins face daily.
Of course, building a complete arsenal goes beyond simply making a few good tooling picks. It would help if you also had robust frameworks that deliver real-time insights and let you take action on demand with easy, intuitive workflows.
Domotz powers live network monitoring and management with enterprise-grade oversight. We help you contextualize your SNMP monitoring insights by putting topology maps, diagnostics, and other vital stats at your fingertips. It’s never been easier to stay so well-informed.
Accomplish more with SNMPv3. Discover why 4,000 MSPs, IT professionals, and System Integrators in 190 countries depend on Domotz for more accessible, economical network monitoring. Start your free trial today.
Further reading: