Subinterface Frame-Relay configuration

I already mildly discussed this subject with Chris, but he felt it would be beneficial to get the board members involved as well as to anyone studying for their CCNA.

When working in a partial mesh frame-relay network, when a subinterface is programmed with specific PVC DLCI information is needed, what exactly is the parameter point-to-point or multipoint tell the cisco IOS and is it needed? For example, lets say you are accessing serial0 on router1 and programming it for a point-to-point PVC with an arbitrary subinterface number

[code:1] router1(config)# interface serial0.1 point-to-point [/code:1]

The text I used for the CCNA didn't really explain what this parameter did and how it affects the sub-interface. My first guess was that it was a descriptionary parameter to make troubleshooting easier, but something tells me my guess is wrong.

hi,

although i am not so sure on this and this is just my own personal theory, i beleive that it has something to do on the behavior of the router towards the subinterface with regards to be it point-to-point or point-to-multipoint rather than just being a descriptive text of that subinterface. i'm guessing that it defines how the subinterface would operate at the same time pass packets to and from its single point or multipoint destination. (although this is just my theory of course, i would also love to hear other's thought as i am also studying for the ccna :lol: )

I use a point to point topology, not fully meshed. I never specify when I build a sub-intfc. These commands are used when the PVC order from the service provider specifies Point to Multi-point VC. Fully meshed would allow for a VRF table to be kept by the service providers router as in the case of MPLS or IPVPN service. Otherwise when you trace to another entity within your network it would first go to the hub then to the other remote.

Hello Cyber,
As u r using Partial mesh so you should use"point to point" type of subinterface because:-
Point to point is used when a single VC ic connecting router to router.
multipoint is used when you have router at the center of VC.

Your Buddy,
Balli