cisco ccna knjiga

cisco ccna knjiga.The subinterface number can take values from 1 to over 100 million. It does not matter what subinterface number you choose to use, as long as it is unique among all subinterfaces of the physical interface. The router uses the subinterface number to distinguish between different subinterfaces of a physical interface. After creating a subinterface, notice that the prompt changes from Router(config)# to Router(config-subif)#oAfter creating a subinterface, you can delete it by prefixing the command interface with the parameter no. However, the deleted subinterface remains in the router's memory. To delete a subinterface completely, you need to save the configuration and reboot the router. For example, to change the subinterface type from multipoint to point-to-point or vice versa, you must delete the subinterface, save the configuration, and reboot the router.Configuring Frame Relay Using SubinterfacesTo configure Frame Relay using a subinterface, you must associate DLCI to the subinterface using the command frame-relay interface-dlci.Router(config)# interface serial [slot_#/]port_#.subinterface_# (point-to-point | multipoint) Router(config-subif)# frame-relay interface- dlci local_DLCI_#For a point-to-point subinterface, only one VC (i.e., one DLCI) can be associated to it; for a multipoint subinterface, multiple DLCIs can be associated to it. When creating a sub-interface, the sub-interface number is usually specified as the corresponding DLCI number; but don't forget that the two numbers are not related at all and can be completely different. Also, be sure to assign the Layer 3 address to the sub-interface, not the physical (primary) interface. However, the frame type and LMI type are configured on the physical interface.The command frame-relay interface-dlci uses reverse ARP for dynamic resolution. If you cannot or do not want to use reverse ARP, you can perform manual resolution on the subinterface using the command frame-relay map, as shown below.Router(config)# interface serial [s2ot_#/]port_#.subinterface_^ (point-to-point | multipoint} Router(config-if)# frame-relay map protocol_ name destination_address local_dlci_^ [broadcast] [ietf | cisco]Multipoint Subinterface Frame Relay Configuration Example This section presents an example of configuring Frame Relay connections on a router using multipoint subinterfaces for a network such as the one shown in Figure 25.13. In this example, assume that the LMI type is automatically detected and that only one multipoint subinterface is used on Router A.Router B E0