The abilities to control which devices get addresses and track the address assignments for auditing purposes are important issues that can be accomplished using DHCPv6. Ironically, privacy is another reason that DHCPv6 could be a good idea. Normally IPv6 addresses contain the MAC address, a unique ID that can be linked back to a specific system. DHCPv6 could be used to break the link between the MAC address and the Layer 3 address. Stateless DHCPv6 is a m..
An AS is multihomed if it has more than one exit point to the outside world. An AS can be multihomed to a single provider or multiple providers. A nontransit AS does not allow transit traffic to go through it. Transit traffic is any traffic that has a source and destination outside the AS. Figure 4-5 illustrates an AS (AS1) that is nontransit and multihomed to two providers, ISP1 and ISP2. Figure 4-5. Multihomed Nontransit AS Example A nontransit AS would only advertis..
Summary Link-State Types 3 and 4
Summary type 3 propagates information about a network outside its own area. Many network administrators assume that summary LSA generates information outside the area by summarizing routes at the natural network boundary, although this has been proven untrue. For example, a summary LSA will not summarize all subnets of a major network 131.108.0.0 in a /16 route. Summary in OSPF does not mean that summarize occurs at the classful network boundary. In this case, s..
The richness of the Cisco QoS toolset allows for a myriad of QoS design and deployment options. However, a few succinct design principles can help simplify strategic QoS designs and lead to an expedited, cohesive, and holistic end-to-end deployment. Some of these design principles are summarized here; others, which are LAN-, WAN- or VPN-specific, are covered in detail in their respective design chapters. General QoS Design Principles A good place to begin is to decide which c..
v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Frame Relay relays or forwards frames from the source to the destination through a Frame Relay network on virtual path connections. These virtual paths can be either permanent virtual circuits (PVCs) or switched virtual circuits (SVCs). A PVC, as its name implies, is a permanent virtual connection. It is usually set up by the ca..
