 supporting longer addresses, and for the protocol to work on a per-link instead of a per-subnet basis. In addition to the changes caused by longer addresses, other changes were also made, such as changing to use ESP instead of OSPF's own authentication methods. However, the fundamental mechanisms did not need to change. Changes to IS-IS An implication of IPv6 to IS-IS is the need for two new options, as defined in RFC 5308 [151]. The first option is called IPv6 Reachability, and it is used to pass information regarding the IPv6 prefix and its length, a metric, and a couple of control bits including one describing whether the information has been 'externally' learned from another routing protocol. The second option is called the IPv6 Interface Address that is effectively oth- erwise similar to the corresponding IPv4 option, but allows addresses of 128 bits. IS-IS works on top of layer 2, and hence IPv6 does not impact the transportation of this protocol. IPv6 Routing for Low-power and Ad-hoc Networks Special focus for IPv6 routing has been given to low-power wireless networks and ad-hoc networks, which often do not even support IPv4. In these networks mesh topologies are commonly used, and routing has to consider the very constrained nature of the routing nodes. Protocols that have been developed in this area include RPL [64]. As this book is not about low-power networks, we do not discuss how these protocols work. We suggest the readers to study the literature related to sensor networks and routing. 3.10.5 Management Information Base The Simple Network Management Protocol (SNMP) is the standard for managing network nodes in the Internet [153]. The information that SNMP uses for management is defined in Management Information Bases (MIBs). There are hundreds of MIBs and hence also some for IPv6. The most relevant MIBs for IPv6 are RFC 4292 'IP Forwarding Table MIB' [154] Deploying IPv6 in 3GPP Networks and RFC 4293 'Management Information Base for the Internet Protocol (IP)' [155]. The MIBs are supported by nodes