Abstract Syntax Notation One (ASN.1) is a formal language for abstractly describing messages to be exchanged between distributed computer systems.
Objects in a MIB are defined with the ASN.1 naming scheme that assigns each object a long prefix that guarantees that the name will be unique. For example, an integer that counts the number of IP datagrams that a device has received is named: iso.org.dod.internet.mgmt.mib.ip.ipinReceives.
The following figure depicts the ASN.1 naming scheme example.
This object name is represented in an SNMP message by assigning each part an integer. So, the above message would appear as 1.3.6.1.2.2.4.3.
Each integer has the following meaning:
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1 = ISO (International Organization for Standardization)
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3 = identified organization (one of branches under the ISO root)
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6 = U. S. Department of Defense (DoD) (one of the children under branch1.3)
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1 = the Internet subtree under 1.3.6
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2 = the mgm branch — (one of seven) of the Internet subtree. It is managed by the Internet Assigned Numbers Authority, and includes the standard MIBs
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2 = mib-2(1) group of managed objects
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4 = ip (the mib-2(1) IP group (one of 11))
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3 = ipinReceives (the MIB object)
