CCNP BCMSN Exam Cram 2 (Exam Cram 642-811)
Terms you'll need to understand:
Techniques you'll need to master:
VLANs contain broadcasts, which enable you to scale your switched networks to much larger sizes. One of the downsides of this is that to pass traffic between VLANs (different subnets), you'll need a Layer 3 device, such as a traditional router or multilayer switch. This Layer 3 switching process is defined in the network layer of the seven-layer OSI Reference Model. This chapter covers both a traditional approach to this problem, using external routers, as well as multilayer switching (MLS) with internal routers. Because of the shift toward client/server applications, the deployment of bandwidth-intensive multicasting applications, the need for improved response time, the need for high-speed switching, and the centralization of servers have all become critical components in a network design. To provide the necessary scalability in today's large campus environments, new technologies are needed to enhance both Layer 2 and Layer 3 performance. The last chapter discussed many enhancements that you can configure on your switches to deal with STP. With the introduction of MLS, networks can scale their applications to any size and contain their broadcast and multicast problems. This enables them to take advantage of Layer 2 switching speeds and price and still take advantage of the redundancy, convergence, and load balancing of Layer 3 routing protocols, such as IS-IS, OSPF, and EIGRP. |