ccna 2 practice skills assessment

ccna 2 practice skills assessment.To find all the PVCs associated with an interface or sub-interface, simply browse to the shaded portion of the output in Example 14-21. In this example, S0/0/0.2 lists only one PVC for DLCI102, so in this case there is only one PVC associated with interface S0/0/0.2. (3) Determine which PVC can reach a particular neighbor (sub-step d of step 3) oWhen the router configuration associates more than one PVC with an interface or subinterface, the next step is to figure out which PVC is used to communicate with another specific neighbor. For example, Example 14-21 shows a multipoint subinterface S0/0/0.34 for R1 using DLCI 103 and 104. so if you are troubleshooting a failed ping 10.1.34.3 command problem for R1, the next step is to determine which of these two DLCIs (103 and 104) identifies the VC that connects R1 to R3.Unfortunately, it is not always possible to find this answer without looking at other documentation. The only show command that helps is show frame-relay map, which correlates the next-hop IP address with the DLCIO but, if the local router relies on reverse ARP, this local router is not informed of the mapping information now either, so this mapping table may not have any useful information. However, if a static mapping is used, then the correct PVC/DLCI can be identified.In this example, when R1 fails to ping 10.1.2.2 (R2), this step can be ignored here because only one PVC is associated with the correct S0/0/0.2 interface, and this PVC has already been identified.(4 ) PVC status. At this point in the troubleshooting step 3, the correct output interface/sub-interface and the correct PVC/DLCL have been identified Finally, the PVC status is checked to determine if something is wrong with the PVC.Routers use 4 different PVC status codes. A router can get two possible status values: Active and Inactive, via LMI messages from the Frame Relay switch. The LMI message from the switch lists all DLCIs for all PVCs configured on the access link, and whether the PVC is currently available (active or inactive).Active: The Frame Relay network knows the PVC by the listed DLCI and that the PVC is working. Inactive: The Frame Relay network knows about the PVC by the listed DLCI, and the PVC is not currently working. Two other PVC states are not available through LMI, one of which is called Static. If LMI is disabled,If LMI is disabled, the router cannot get any information about the PVC state from the switch. Therefore, the router lists all of its configured DLCIs in a static state, i.e., statically. Although the router does not know if these PVCs are operational, it can at least send some frames using these DLCIs and expect the Frame Relay network to deliver them.306 Chapter 14 Implementing Frame Relay14.2 Basic Content 307 Another PVC state is Deleted, which is used when the LMI is functioning properly but the switch's LMI messages do not involve any specific DLCI values. If the router has configured a DLCI (for example, in the frame-relay interface-dlci command), but the switch's LMI messages do not list that DLCI, the router displays that DLCI as deleted. The implication of this statement is that the router is configured with a DLCI,but the switch is not. In a real-world network, a deleted status could mean that the router or switch is misconfigured or that the Frame Relay switch has not been configured with the correct DLCIO Table 14-3 summarizes the four types of Frame Relay PVC status codes.