Before you can modify port settings, you must select one or more switch ports. Even though they have traditionally been called ports, Catalyst switches running the Cisco IOS Software refer to them as interfaces. To select a single switch port, enter the following command in global configuration mode: Switch(config)# interface type module/number The port is identified by its Ethernet type (fastethernet, gigabitethernet, tengigabitethernet, or vlan), the physical ..
EIGRP Basics and Steady-State Operatio
Many CCIE candidates have known, at least at some point, many of the details of EIGRP operation and configuration. EIGRP is widely deployed and is thoroughly covered on the CCNP BSCI exam. With that in mind, this chapter strives to review the key terms and concepts briefly, and get right to specific examples that detail EIGRP operation on a Cisco router. To that end, the chapter begins with Table 9-2, which lists some of the key features related to EIGRP. Table 9-2 EIGRP Fea..
When EIGRP loses its successor or primary route, EIGRP immediately tries to reconverge by looking at its topology table to see if any feasible successors are available. If a feasible successor is available, EIGRP immediately promotes the feasible successor to a successor and informs its neighbors about the change. The feasible successor then becomes the next hop for EIGRP to forward the packets to the destination. The process by which EIGRP converges locally and does not invo..
In this example, Router4 will dial into Router1 by using an ISDN circuit: Router4#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router4(config)#username Router1 password 0 cisco Router4(config)#interface BRI0 Router4(config-if)#ip address 192.168.15.4 255.255.255.0 Router4(config-if)#encapsulation ppp Router4(config-if)#ip ospf demand-circuit Router4(config-if)#dialer map ip 192.168.15.1 broadcast 4165550000 Router4(config-if)#dialer-g..
By default, a Catalyst switch detects an error condition on every switch port for every possible cause. If an error condition is detected, the switch port is put into the errdisable state and is disabled. You can tune this behavior on a global basis so that only certain causes trigger any port being disabled. Use the following command in global configuration mode, where the no keyword is added to disable the specified cause: Switch(config)# [no] errdisable detect cause ..
