| A | B |
|---|
| subinterfaces | multiple logical interfaces are created from one physical interface, |
| Subinterfaces are logical | subdivisions of a physical interface |
| In a subinterface configuration, each PVC can be configured as a | point-to-point connection, which allows the subinterface to act as a dedicated line |
| The overall cost of implementing a Frame Relay network can be reduced by | implementing subinterfaces |
| Subinterfaces can resolve | split horizon issues |
| Split horizon reduces routing loops by | not allowing a routing update received on one physical interface to be sent back out that same interface. |
| subinterfaces to support the connection types | point-to-point and multipoint |
| In Point-to-point connection a single subinterface is used to | establish one PVC connection to another physical interface or subinterface on a remote router. |
| In Point-to-point the interfaces would be | in the same subnet and each interface would have a single DLCI |
| Each point-to-point connection is | its own subnet |
| In a point-to-point environment, broadcasts are not a problem because | the routers are point-to-point and act like a leased line. |
| Multipoint -- A single subinterface is used to establish | multiple PVC connections to multiple physical interfaces or subinterfaces on remote routers |
| In amultipoint connection, all the participating interfaces would be in the same subnet, and | each interface would have its own local DLCI. |
| In a multipoint environment, because the subinterface is acting like a regular Frame Relay network, routing updates are | subject to split horizon |
| A basic Frame Relay configuration assumes that you want to configure Frame Relay on one or more physical interfaces and | that LMI and Inverse ARP are supported by the remote router(s). |
| In a basic FR configuration,the LMI notifies the router about | the available DLCIs |
| In a basic FR configuration, inverse ARP is enabled by | default, so it does not appear in configuration output. |
