As a network administrator, you are more likely to generate custom reports on network usage frequently. Even though traditional tools provides basic functionalities, you still need to retrieve any network statistic from your device. Seasoned network administrators use OIDs, MIB browsers, and SNMP poll to get custom data from devices.
Before starting an in-depth probe, you need to understand where MIBs and OIDs can be used, and its basic applications. For instance, you have a group of network devices that you want to monitor regularly. In any type of network, administrators look for key network information from the devices monitored, at pre-defined intervals. The type of information can be the status of a device or any hardware information. Generally, administrators employ a monitoring tool that helps to automate the processes. For example, if you want to monitor the temperature of the Cisco® switch, you can easily poll it using SNMP. The information that you poll, is available as a raw data in your network device. The raw data (e.g. hardware temperature) is called an ‘object’ that resides within the device in a database, i.e. Management Information Base (MIB), and every object (the device statistics that you are trying to poll) is uniquely identified with an object identifier i.e. OID.
What is MIB?
MIB is a collection of information used for managing devices in the network. Network devices have a database called ‘MIB’ or ‘MIB table’ or ‘MIB Tree’ with the set of ‘objects’. These object stores valuable information like memory status, hardware status, etc. within the network device.
What is OID?
OID or Object Identifier, is an identifier used to name and point to an object in the MIB hierarchy. As mentioned earlier, SNMP-enabled network devices (e.g. routers, switches, etc.) maintains database of system status, availability and performance information as objects, identified by OIDs. It will be a piece of quantifiable data which gives you statistical information to maintain an effective network system.
For instance, if you want to retrieve information on managed systems up time (sysUpTime) from your device. Your MIB request will be as, OID = (18.104.22.168.22.214.171.124.0). When an SNMP manager asks for the value of (126.96.36.199.188.8.131.52.0), it basically reads the request, giving the SNMP agent present in your network device the path to follow in order to find sysUpTime object. After locating, it retrieves that information from the MIB table and reports to you.
Where to use MIBs & OIDs? And How to manage them?
Considering that each network device have its own MIB table and multiple OIDs within them, you have more than million OIDs accounted for. It is physically impossible to know all those OIDs and MIBs while managing your network. Network management systems usually provide both basic and detailed performance information about your network devices. But to go an extra mile and poll custom MIB objects, administrators have to use MIB browsers that will helps to find OIDs. Custom pollers can be used to poll those OIDs to retrieve any information, by helping administrators to monitor devices with multiple statistical data.