Frame Relay Questions

I have compiled as set of questions about Frame relay, this is my small quiz about the Frame-Relay technology:

1. How can you disable LMI? What are the results?

Disabling LMI makes inARP no longer works (because nothing triggers a router to send an inARP message.

no keepalive

2. How can you reset inARP entries?

Two ways. First one, shutdown the interface and second one, it’s to use  the command:

clear frame-relay inARP

3. Which command will you use to verify frame-relay maps?

show frame-relay map

4. Scenario: We have two routers connected to a Frame Relay Network. R1 is using a point-to-point configuration while R2 is using a multipoint interface with a dynamic map. Once the VC is up, we try to disable the inARP on R1. What will happen?

You cannot disable inARP in a point-to-point interface.

5. How can you  check LMI type?

There are 3 LMI types which are:

• cisco: Allowed dlci range: 16-1007 (cisco propietary)
• ansi:  allowed dlci range: 16-991
• itu: allowed dlci range: 16-991

The commands to verify the LMI type are:

    show interface x/x/x

    show frame lmi

6. Which command will use to modify the lmi type?

    frame-relay lmi-type type

7. Which to commands can you use for Mapping DLCI to L3 addresses?

    frame-relay map

    frame-relay interface-dlci

8. What types of frame relay encapsulation are and how can you configure it?

• ietf
• cisco

    encapsulation frame-relay ietf

    frame-relay interface-dlci ietf

    frame-relay map dlci ietf

The default encapsulation type is cisco.

9. What is the broadcast keyword use for?

The broadcast keyword tells the router to send copies of broadcast and multicast packets over a specific DLCI.

Without the broadcast option, dynamic routing protocols such as EIGRP, OSPF and RIPv2 would not be able to advertise multicast route updates over the DLCI.

10. Is it possible to ping your own ip on a multipoint frame-relay?

By default, you are not able to ping your own ip.  To be able, you need to configure a  static map for  your own IP address to use the local DLCI.

This is because Frame Relay multipoint interfaces are non-broadcast, (unlike Ethernet and point-to-point interfaces High-Level Data Link Control [HDLC]), and Frame Relay point-to-point subinterfaces.