Selecting the Right SNMP Remote Monitoring Equipment for Your Network

The basics of SNMP: SNMP Tutorial

SNMP remote monitoring is a vital function for any company with a large network. When you have a network that isn't isolated within a single area, you need assistance to manage it remotely. Integrating monitoring SNMP protocols allows you to streamline remote network visibility. There's just no way (at least, no economical way) to station a live human being at each remote site to monitor everything that happens there.

What distinguishes SNMP remote monitoring from other types of remote monitoring is the use of SNMP ("Simple Network Management Protocol") to transmit messages between central alarm master (an SNMP manager, by definition, in this case) and the SNMP remotes at each network site. This makes monitoring SNMP systems ideal for large-scale, distributed networks. As we discuss more SNMP pros and cons, you'll notice the pros of SNMP are many, and the cons are quite few.

The Pros and Cons of SNMP Remote Monitoring

One of the benefits of SNMP - even possibly the main advantage of SNMP - is that it is an open standard. Open protocols are designed to combat the wasted effort and costs when one manufacturer develops its own "proprietary" protocol that only it will support. Utilizing open-standard SNMP monitoring ensures scalability and compatibility with a wide range of devices. Anyone who buys remote monitoring devices that use these protocols is asking for trouble. The manufacturer may raise prices with little threat of damaging sales volume, since they are "the only game in town." Worse yet, the manufacturer may close up shop. At this point, there is no way to get new products or parts to add or repair your remote monitoring system. You'll most likely end up suffering with a dead-end system rather then switching over to a new system all at once. There's no way to gradually transition between systems if one side doesn't work with the other.

The cons of SNMP, which are small compared to its openness, include security risks that are normal whenever using an open standard. There is "security through obscurity" linked with any little-used communications standard. Monitoring SNMP traffic securely - especially using SNMPv3 - is crucial to mitigating these risks. Still, the release of SNMPv3 added new encryption and privacy options that had never before existed within SNMP.

SNMPv3 introduces robust security measures by defining specific security models and levels that enhance data protection:

• User-based Security Model (USM): USM provides essential authentication and encryption for SNMP messages. It utilizes mechanisms like HMAC (Hash-based Message Authentication Code) and cryptographic algorithms such as MD5 or SHA (Secure Hash Algorithm) to ensure data integrity and confidentiality.
• View-based Access Control Model (VACM): VACM allows for fine-grained access control by defining access policies and rules based on Management Information Base (MIB) views, ensuring that only authorized users can access specific data.
• Transport Security Model (TSM): TSM focuses on securing communication by supporting transport-level security protocols like Transport Layer Security (TLS), which adds an additional layer of protection during data transmission.

SNMPv3 also defines three distinct security levels, each providing different degrees of protection:

• noAuthNoPriv: This level offers no authentication or encryption, suitable for environments where security is not a primary concern.
• authNoPriv: Utilizing HMAC for message authentication, this level ensures that the data is from a verified source, although it does not encrypt the content.
• authPriv: Combining both authentication and encryption, this level provides the highest security, protecting SNMP messages from unauthorized access and tampering.

SNMP is also a rather detailed protocol. Detailed messages are sent between devices, not just small preset codes. This downside has been rendered quite small in most applications, since bandwidth has skyrocketed in recent years. In an SNMP remote monitoring system, the two major components are an SNMP manager and SNMP agents.

The SNMP Manager is the central console used by a human operator. It sorts alarm data received from each remote SNMP agent throughout the network. Efficiently monitoring SNMP managers can significantly reduce response times. Additionally, the SNMP manager is responsible for initiating requests to gather data from devices and processing the collected information to generate insightful reports and trigger necessary alerts.

SNMP Agents are located at remote sites, and they fall into two major groups. A lot of modern gear supports SNMP natively. It can send its own alarm messages to the SNMP manager directly. Since not all gear that must be remotely monitored is SNMP-capable, however, SNMP remotes are also required. These devices accept alarms from non-SNMP gear, usually in the form of a discrete contact closure. The alarm remote, which is SNMP-capable, then sends an SNMP message back to the SNMP manager. In this way, both SNMP and non-SNMP devices can be managed under the same SNMP manager group.

How to choose the right SNMP remote
How to choose the right SNMP manager

Beyond these primary components, SNMP monitoring also involves:

• Managed Devices: These are the network equipment being monitored, such as routers, switches, servers, and printers. Each managed device has an SNMP agent installed to facilitate communication with the SNMP manager.
• Management Information Base (MIB): This is a crucial database that organizes the information available for monitoring and managing SNMP devices. It consists of objects representing specific attributes or parameters of the managed devices.
• Object Identifier (OID): Each object in the MIB is identified by an OID, a numeric sequence that acts like an address in the MIB hierarchy, ensuring precise data retrieval and management.

Understanding these components and their interactions provides a comprehensive view of how SNMP monitoring operates, ensuring both SNMP-enabled and non-SNMP devices are efficiently monitored within the same network infrastructure.