frame-relay config question

aueddonline

right i think i'm getting somewhere is this right

frame-relay interface-dlci - this can be used on a multipoint interface but inverse arp need to be enabled. It is also always used on point-to-point subinterfaces.

if inverse arp isn't used the on multipoint subinterfaces the

frame-relay map ip (destination ip)(destination dlci) broadcast

command is used to statically map the dlci to a layer 3 address.


right I have got another question does anyone know how to change an subinterface say s0/0.1 that has been configured as a point-to-point to a mulitpoint or visa versa?????
i've tried
no interface s0/0.1
and when i come to re-create it as the other type it says cannot change type. because i'm a bit concerd that if i want to config a multipoint on the exam and I forget to type anything i.e int s0/0.1 <enter>
it will become a point to point and i won't be able to change it back.

Thanks for reading

Netstudent

frame-relay interface-dlci - this can be used on a multipoint interface but inverse arp need to be enabled. It is also always used on point-to-point subinterfaces.

Thats right. In addition, You can use the map statement on subinterfaces. I don't think you have to use frame interface-dlci on a subinterface. Depends on the application. Inverse-arp is enabled by default, but it is disabled by default when you use the frame map statement. Is it also disbaled on p-t-p interfaces because discovery is not needed.

if inverse arp isn't used the on multipoint subinterfaces the

frame-relay map ip (destination ip)(destination dlci) broadcast

command is used to statically map the dlci to a layer 3 address.

Correct. It would be the remote IP and the local DLCI. The local DLCI that would be used to send the frame onto the right VC.

right I have got another question does anyone know how to change an subinterface say s0/0.1 that has been configured as a point-to-point to a mulitpoint or visa versa?????
i've tried
no interface s0/0.1
and when i come to re-create it as the other type it says cannot change type. because i'm a bit concerd that if i want to config a multipoint on the exam and I forget to type anything i.e int s0/0.1 <enter>

If you try to do int s0/1.1<cr> it should come back as an incomplete command unless you have already created a p-t-p to multipoint on s0/1.1.

You probably need to do a "no interface s0/0.1 point-to-point". To be honest with ya i don't think I have changed it like that. If I did I don't remember.

http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/wan_c/wcdfrely.htm#wp1002586

r_durant

Thats right. In addition, You can use the map statement on subinterfaces. I don't think you have to use frame interface-dlci on a subinterface. Depends on the application. Inverse-arp is enabled by default, but it is disabled by default when you use the frame map statement. Is it also disbaled on p-t-p interfaces because discovery is not needed.

I'm not sure if you "have" to use the frame interface-dlci command, but it is used on sub-interfaces...

Here's a snippet from one of our core routers...

interface Serial0/0/0.110 point-to-point
description PRIMARY LINK TO XXXX XXXX
ip address x.x.x.x 255.255.255.252
frame-relay interface-dlci 110

RD

aueddonline

just picking up on that point tried this command and this is what I got????? anyone???

#no int s0/0.1 point-to-point
Not all config may be removed and may reappear after reactivating the sub-interface

Netstudent

YOu may have to change the subinterface number then.

R1(config)#int serial 0/0.1 multi
R1(config)#int serial 0/0.1 multipoint
% Warning:  cannot change link type

r_durant

aueddonline wrote:

just picking up on that point tried this command and this is what I got????? anyone???

#no int s0/0.1 point-to-point
Not all config may be removed and may reappear after reactivating the sub-interface

Did you save the config and do a reload? If you haven't, save the config, do a reload and then do a "sh ip int bri" and see if the interface still shows up...