SNMP port is used for managing ip devices like computers, switchers, servers, ip video cameras, basically all ip devices that are connected to a network. The snmp or simple network management protocol is composed of a few computers with main task of managing ip hosts on the network.

The SNMP port number is 161 and it uses the UDP protocol. On a snmp network there are three components:

1.      Managed device;

2.      Agent, this is the software that is on the managed device;

3.      NMS – network management system , this is the software that  runs on the manager.


SNMP protocol  has the following routine:

          GetRequest: this command is used by the manager to retrieve a value of a variable or a list of variables from the agent;

          SetRequest: this commend is used by the manager to change the value of a variable from the agent;

          GetNextRequest: this command is used by the manager to get available variables from the agent;

          GetBulkRequest: this command is used by the manager when he want to use GetNextRequest for several times;

          Response: this is the acknowledgement of the agent at a manager command;

          Trap response from agent to manager;

          Inform Request: asynchronous acknowledgement from agent to manager or manager to manager.

If you want to change the snmp port settings the following steps need to be taken:

1.      Check the snmp port 161 used for general message to see if he functions correct;

2.      The default snmp port for trap messages is 162; check to test his functionality;

3.      If one of this snmp ports are used by another device then change them by using the local service file located on the agent ; the root to this file is: % SystemRoot %System32Drivers…..