OSPF Stub Router Configuration
Defined in RFC 3137, and first supported in Cisco IOS Software Release 12.2(4)T, the OSPF stub router feature—not to be confused with stubby areas—allows a router to either temporarily or permanently be prevented from becoming a transit router. In this context, a transit router is simply one to which packets are forwarded, with the expectation that the transit router will forward the packet to yet another router. Conversely, non-transit routers only forward packets to and..
A relatively deep knowledge of IP ACL configuration and use is assumed to be pre-requisite knowledge for readers of this book. In fact, many of the examples in the earlier sections of the book did not take the space required to explain the detailed logic of ACLs used in the examples. However, some reference information, as well as statements regarding some of the rules and practices regarding IP ACLs, is useful for general CCIE Routing and Switching exam study. Those details ..
High CPU Utilization Level Troubleshooting
The load on a switch’s CPU is often low, even under high utilization, thanks to the TCAM. Because the TCAM maintains a switch’s forwarding logic, the CPU is rarely tasked to forward traffic. The show processes cpu command that you earlier learned for use on a router can also be used on a Cisco Catalyst switch to display CPU utilization levels, as demonstrated in Example 5-19. Notice in the output in Example 5-19 that the switch is reporting a 19 percent CPU load, with ..
Configuring CBWFQ for Frame Relay
This section discusses the configuration tasks for enabling CBWFQ on Frame Relay PVCs. CBWFQ is configured via the MQC configuration interface; MQC was explained at the beginning of this chapter. Table 18-1 lists the configuration options available for setting up the traffic classes. Table 18-2 displays the class policy configurations available. Table 18-1. Available Options for Setting Up the Traffic Class (class-map) Command (config-cmap) ..
The Origins of Frame Relay: X.25
v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Frame Relay has its roots in the X.25 protocol, a robust packet-switched WAN protocol widely deployed in the early 1970s to connect geographically dispersed LANs and WANs. The X.25 protocol works well on noisy transmission mediums, which observe a high rate of errors and packet drops. X.25's windowing, flow, and error control fe..
