Cisco Certifications Tutorials

15 http:\\ciscocertifications.info · Cisco (Default) · ANSI · Q933a To set up frame relay on an interface just set the encapsulation to frame-relay. Frame relay encapsula- tion can either be Cisco (Default) or IETF. You must use Cisco encapsulation to connect two Cisco routers or IETF if a third party router is involved. Frame Relay configuration is done in the interface configuration mode. Although LMI type is configurable, the Cisco router will try to autosense which LMI type the switch is using. Router(config-if)# encapsulation frame-relay <cisco or ietf> To assign a DLCI to an interface you would type. Router(config-if)# frame-relay interface-dlci <number 16-1007> To set the LMI type you enter: Router(config-if)# frame-relay lmi-type <cisco/ansi/q933a> A keepalive interval must be set to enable LMI on an interface. This is 10 seconds by default and can be set by typing: Router(config-if)# frame-relay keepalive <number of seconds> The Frame Relay Map tells the network protocol how to get from a specific protocol and address pair to the correct DLCI. There are two ways to make this happen, you can use the frame-relay map com- mand or you can use the inverse-arp function. The "frame-relay map" command can be used to show which routers are reachable. Router(config-if)# frame-relay inverse-arp <protocol> <dlci> Router(config-if)# frame-relay map <protocol> <protocol address> <dlci> broadcast <cisco or ietf> With frame-relay you can use subinterfaces to allow multiple virtual circuits on a single serial interface and each subinterface can be treated as a separate interface. You use the interface s0.interface number command: Router(config-if)# interface s0.<subinterface number> <point-to-point or multipoint> You can configure subinterfaces to support the following connection types: Point-to-point A single subinterface is used to establish one PVC connection to another physical interface on a remote router. Each interface would be on the same subnet and have a single DLCI. Each point-to-point con- nection is its own subnet and act like a leased line. Multipoint A single subinterface is used to establish multiple PVC connections to multiple physical interfaces on a remote router. All participating interfaces are in the same subnet and each interface would have it's own DLCI. The subinterface acts like a NBMA network and broadcasts are subject to split horizon rules. It is worthwhile creating a subinterface with a number that matches the DLCI identifier.