Object Identifier

OID(Object Identifier) is a data type used to identify an object in the data structure. It is a sequence of integer numbers, separated by

decimal points who indicates what edge should be selected in the data tree structure to find an object, like in the figure below:

To simplificate the human read, is common to use the name corresponding to the studied object, like 1.3.6.1.2.1.2.

The mentioned object can be found using the object identifier iso.org.dod.internet.mgmt.mib.interfaces.

To access a simple variable, should you insert a ".0" to the object identifier like the variable

1.3.6.1.2.1.1.1.0 (iso.org.dod.internet.mgmt.mib.system.sysDescr.0).

In a table access, you should insert one or more INTEGER's to represent the object's row, and, after it, it's object identifier,

like in 1.3.6.1.2.1.7.5.1.1.127.0.0.1.67 (iso.org.dod.internet.mgmt.mib.udp.udpTable.udpEntry.udpLocalAddress.10.0.0.1.67 or

, to simplificate, udpLocalAddress.10.0.0.1.67). In this case, the udpLocalAddress of the entry 10.0.0.1.67 will be returned.

Note that 10.0.0.1 is an IP of a connection and 67 the used port. Both are collumns of the table.

More information can be obtained in the udp group.