Network management tools can also help in providing security to the systems.
A network management tool known as "The Multi Router Traffic Grapher" is used to monitor the traffic load on all the network links. Emails are also monitored to delete spam and virus-infected emails at server itself and also to ensure that attachments are not too heavy to clog the rest of the system.
Another network management tool "Nagios", which is a network and server monitoring system is also used. Nagios helps monitor network services, processor load, system logs, disk usage, etc. and is capable of providing email and SMS notifications as well. Nagios also allows proactively resolving problems by defining event handlers.
To summarize, network management tools can help a network manager understand when any component of the network is about to fail or has already failed, or whose security has been compromised (e.g. through a viral attack), when the traffic has reached its peak, and most importantly, to know that everything is working fine.
Structure of Management Information (SMI) is a component that is used in network management and provides the rules required in network management. It is based on object definition language known as Abstract Syntax Notation One (ASN.1) and operates in Simple Network Management Protocol (SNMP). It "defines the general rules for naming objects, defining object types (including range and length), and showing how to encode objects and values" (Yang, n.d.). However, SMI does not define the number of objects that an entity should manage. It also does not define the names of the objects that are to be managed. Also, it does not define the how the objects and their corresponding values will be associated.
A managed object has the following three attributes:
a. Name: The name of the object known as the object identifier (OID) is used to uniquely define a managed object. There is no restriction on the type of name - it can be human readable or it could be numeric like an IP address. The naming convention of these managed objects is based on the ASN.1 naming scheme as mentioned earlier, which is hierarchical in nature. So an object identifier is made up of a series of integers separated by dots. These series is based on the nodes in the tree and is hierarchical. The figure below shows an example of an object identifier.
As can be seen from the figure, the management branch (i.e. mgmt in the figure) defines a standard set of internet management objects (hierarchically above mgmt) and is named as iso.org.dod.internet.mgmt or 184.108.40.206.2.
b. Type and syntax: ASN.1 is machine, OS and language independent method for describing data types and rules that define how data will be transmitted over the network. The data-types are described in brief below:
An integer with a value between -231 and 231 - 1
Same as INTEGER
Unsigned with a value between 0 and 232 - 1
Byte-string up to 65,535 bytes long
An object identifier
An IP address made of four integers
An integer whose value can be incremented from zero to 232; when it reaches its maximum value it wraps back to zero