Updating MIBs
MIBs are periodically updated to add new functionality, remove ambiguities and to fix defects. These changes are made in conformance to section 10 of RFC 2578. An example of an MIB that has been updated many times is the important set of objects that was originally defined in RFC 1213 "MIB-II". This MIB has since been split up and can be found in MIBs such as RFC 4293 "Management Information Base for the Internet Protocol (IP)", RFC 4022 "Management Information Base for the Transmission Control Protocol (TCP)", RFC 4113 "Management Information Base for the User Datagram Protocol (UDP)", RFC 2863 "The Interfaces Group MIB" and RFC 3418 "Management Information Base (MIB) for the Simple Network Management Protocol (SNMP)".
Read more about this topic: Management Information Base