Frame Relay ( point to point connection )

[rehabzenati1]

Hi, i would like to Inquire about frame relay protocol

My inquiry is why we need sub-interface in a frame relay in a  point to point connection .

[Vasilii Mikhailovskii]

Hello.

Because FR encapsulation implies a possibility to run multiple DLCIs over single physical interface, so this results in encapsulation challenge (find right DLCI for IP-address).

Once you have p2p sub-interface the encapsulation is obvious.

Also you may have static FR mapping and avoid using sub-interfaces.

[rehabzenati1]

thank you for replying

at first, i am sorry l did not understand your answer .

second, i tried to do static FR mapping at the physical interface but it did not work (the ospfv3 did not propagate their massage's ) however it work with using sub-interfaces (but i do not need it ).

[Vasilii Mikhailovskii]

Hello.

Let me clarify: with p2p interface (like p2p FR sub-interface) there are not problems with encapsulation, as interface itself defines it. But for physical interface you need a mapping, as multiple DLCIs may be running simultaneously.

Static FR mapping (for OSPFv3) should be done for link-local peer address + broadcast for adjacency to come up (for example, frame-relay map ipv6 FE80::1 <dlci> broadcast).

If does not work - please provide running configuration from both ends and check if ping does work.

[rehabzenati1]

hi, thanks a lot .

but what do you mean by " please provide running configuration from both ends and check if ping does work "

[Vasilii Mikhailovskii]

Hello.

You wrote:

second, i tried to do static FR mapping at the physical interface but it did not work

So, to troubleshoot, please provide running configuration that does not work )for OSPFv3) and if you can ping peers.