1. SNMP Neil Tang 12/10/2008
CS440 Computer Networks

2. SNMP
SNMP is used to obtain the state of various equipments and protocols on different nodes.
SNMP is implemented on top of UDP.
SNMP is essentially a specialized request/reply protocol that supports two kinds of request messages: GET and SET.
SNMP also supports a GET-NEXT message which is used to walk through elements of a complex data structure such as a table.
CS440 Computer Networks

3. SNMP Client and Server
A system administrator interacts with a client program that displays information about the network.
The client program uses SNMP to request that information from the node in question.
An SNMP server running on that node receives the request, locates the appropriate piece of information, and returns it to the client program.
CS440 Computer Networks

4. MIB
SNMP depends on a companion specification called the management information base (MIB). The MIB defines the specific pieces of information—the MIB variables—that you can retrieve from a network node.
MIB organizes variables into 10 different groups. For example: System, IP, TCP, …
MIB is essentially a database with a tree structure. MIB assigns a globally unique identifier to each MIB variable. For example, is the unique ASN.1 identifier for the IP-related MIB variable ipInReceives; this variable counts the number of IP datagrams that have been received by this node.
CS440 Computer Networks