SNMP MIB Changes Related to IPv6
Simple Network Management Protocol (SNMP) is part of IETF’s Internet Protocol Suite that consists of four abstraction layers and defines a set of protocols used on the Internet. SNMP is mainly used for management and monitoring of networked devices. It can inform about the health of a network device or other reflections of its state (interfaces, IP addresses, traffic and more). SNMP is defined as part of IETF RFC 1157. For its function, it leverages Management Information Bases (MIBs), which define the structure of device information maintained. They represent a hierarchical namespace containing object identifiers (OIDs). Each OID identifies an object that holds the information of interest and can be polled or set via SNMP.
Now, it is common knowledge that IPv6 has gained great attention, especially after the IPv4 address exhaustion reports. At the same time, IPv6 had brought a number of challenges to SNMP. These are not as much related to SNMP itself (as an Application layer protocol, SNMP should work with either IPv4 or IPv6 at the Network layer) as to the MIB objects carrying network addresses. It is obvious that SNMP MIB OIDs contain information for multiple OSI or TCP/IP layers, and thus the differences between IPv4 and IPv6 would in turn be reflected in the OIDs tied to them.
Our recently published white paper in the new IPv6 section of the Cisco Security Intelligence Operations portal describes the challenges that IPv6 posed to legacy SNMP OIDs, and the approach that was adopted by IETF, Cisco’s adoption, and the current industry direction in the area.