ccna 2 chapters pdf

ccna 2 chapters pdf.A 140.1.2.0/24 140.1.2.1 Point to pointD 140.1.2.0/24 140.1.2.4 Point to pointA 140.1.3.0/24 140.1.3.1 Point to pointE 140.1.3.0/24 140.1.3.5 Point to pointMultipoint subinterfaces operate best when there is a full mesh interconnection between a group of routers. Referring to the other two routers, a multipoint subinterface configuration is used on Routers A, B, and C, as these three routers can be considered to form a subnet with a full mesh interconnection.The term multipoint simply means that there is more than one VC, so it is possible to send and receive over one and more VCs at the subinterface. Similar to point-to-point subinterfaces, multipoint subinterfaces use the frame-relay interface-dlci command. Note that in this case, there are two commands for each multipoint subinterface because it must be determined which of the two PVCs associated with the interface is the PVC used by that subinterface.Router A is the only - router that uses both multipoint and point-to-point subinterfaces. On Router A's multipoint SerialO/1/l.l interface, the DLCIs for Router B and Router C are listed. on Router A's other two point-to-point subinterfaces, only a single DLCI needs to be listed. in fact, only one frame-relayinterface-dlci command is allowed on the point-to-point subinterface because only one VC is allowed . otherwise the configuration is similar between the two types.Example 14-13. the configuration shown in Example 14-17 does not require a mapping statement because reverse ARP is enabled by default on multipoint subinterfaces. again no mapping is required for point-to-point subinterfaces because the unique DLCI associated with the interface has been statically configured using the frame-relay interface-dlci command.Example 14-18 lists another showframe-relay map command that shows the mapping information known by reverse ARP for a multipoint subinterface. Note that the output includes the Layer 3 address, whereas the same command used for the point-to-point subinterface (in Example 18-12) does not include the Layer 3 address. The reason for this is that the route may refer to the next-hop IP address that is reachable through the multipoint interface, but because more than one DLCI is associated with that interface, the router needs to match the next-hop IP address with the correct DLCI using the mapping information.Example 14-18 Frame Relay Mapping and Reverse ARP on Router C