frame relay multipoint dlci query

hi i have configured in the passed frame relay but now i wish to connect 3 branch routers from 1 serial connection via my main hub:

it appears there are different types of configurations of frame relay and need to get the correct format/configuration correct first.

i currently have connected a (hub & spoke) type topology ie

main hub

int s0/0
encapsulation frame-relay
no shut

int serial0/0.20 multipoint
frame-relay interface-dlci 201 - currently connected to branch router a
frame-relay interface-dlci 202 - branch router b
frame-realy interface-dlci 203 - branch router c
no shut

---------------------------------------------

branch-router-a - currently shows as up/up via branch a router
int s0
encapsulation frame-relay
no shut

note: currently i only have single serial dce/dte cables

question 1.  do i need to purchase a single serial cable that has multiple serial connections branching from the same serial cable in order to configure the above so that i can connect to dlci 202 & 203  ?

question 2.  i also wish to setup 'point-to'point' connections from the same cable above  ?
mikey250Asked:
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Don JohnstonInstructorCommented:
question 1.  do i need to purchase a single serial cable that has multiple serial connections branching from the same serial cable in order to configure the above so that i can connect to dlci 202 & 203  ?

That's not how it works. For every site (router) that you want to connect to, you will need a serial cable (like the one you've got) for each connection. That means you will need a router with four serial ports (one for each branch site and one for your HQ site).

This page shows how you would setup a frame-relay network with three sites using a 2523 router that is configured to simulate a frame-relay cloud.
mikey250Author Commented:
hi don,  i have already setup a topology like your example using those commands.

hence why was trying to setup this type below as the example i have shows the below

main hub

int s0/0
encapsulation frame-relay
no shut

int serial0/0.20 multipoint
ip address 172.16.1.1 255.255.255.240
frame-relay interface-dlci 201 - branch router a
frame-relay interface-dlci 202 - branch router b
frame-realy interface-dlci 203 - branch router c
no shut


branch-router-a - shows as up/up
int s0
encapsulation frame-relay
no shut


int serial0.0.21 point-to-point
ip address 172.16.1.17 255.255.255.252
frame-relay interface-dlci 221
no shut

for example!
Don JohnstonInstructorCommented:
What is your question?
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mikey250Author Commented:
i assumed the example you showed me was specifically for that topology which is what i have already setup before.

now i wanted to use the commands ie (interface-dlci)  to connect routers a b & c to the main hub  for (multipoint & point-to-point) so i assumed the example was not used at all so how  ?
Don JohnstonInstructorCommented:
What do you mean when you say "main hub"?  The frame-relay switch?  Or the site that you want to the other sites to be able to talk to?

Please post your topology or the config of the frame-relay switch.
mikey250Author Commented:
yes my 'main hub is my frame-relay-switch'

         frame-relay-switch
                       |
                       |
      --------------------------------
      |               |                 |
router-a | router b | router c

I have no topology drawing yet but router a, b & c will connect to my frame-relay-switch.
Don JohnstonInstructorCommented:
With just three routers, it's not very practical to do a multipoint config.

On a physical interface type config, it would look like this:
int s0/0
 encap frame-relay
 ip address 192.168.1.1 255.255.255.0

Open in new window

Inverse ARP will be used to learn the local DLCI's and the distant IP addresses.

If you want to get the exact same result with a multipoint config, it would look like this:
int s0/0
 encap frame-relay
 int s0/0.1
  ip address 192.168.1.1 255.255.255.0
  frame-relay map ip 192.168.1.2 102 broadcast
  frame-relay map ip 192.168.1.3 103 broadcast

Open in new window


So when you're dealing with just two other sites, there's absolutely no reason to use a multipoint configuration.  Unless you get paid by how many commands you type in. ;-)
mikey250Author Commented:
hi don,

yes i have already configured a topology using 'frame-relay map ip x.x.x.x 102 broadcast' also but sometime ago and made use of the 'no split-horizon' making also use of 'eigrp 100' routing protocol so that each of my branch routers could 'ping vica versa through the frame-relay-switch-cloud.

hence wanting to know how to make use of configuring my routers for a new topology making use of the 'interface-dlci' specifically.

note: i have not yet realised if any of these commands can be mixed yet but that will be for another thread question.
mikey250Author Commented:
the reason for asking is because i will now be working within a team at my (isp) and am going to also providing support.
Don JohnstonInstructorCommented:
hence wanting to know how to make use of configuring my routers for a new topology making use of the 'interface-dlci' specifically.
the interface-dlci command is not used in a multipoint sub-interface configuration.  It is used in a point-to-point configuration.

I'm still unclear as to what your question is though.

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mikey250Author Commented:
hi don, my apologies for no clarity.

i have just answered my own question without realising as i should have realised but for some reason i was under the impression 'interface-dlci' command could be used with dlci 'multipoint'

multipoint - ok so no 'interface-dlci' command used here - understood.

'point-to-point' using 'interface-dlci' - only on point-to-point networks

i understand now.

thanks for making me realise!!
Don JohnstonInstructorCommented:
Glad to help.

It's... unfortunate that you have to deal with Frame-Relay.  It was (still is, actually) a good protocol, but it's just not seen as much as it was back in the 90's.  I don't think I've seen a F/R connection to a production network in over 10 years.  

I don't know about you, but I hate having to learn a technology that will probably be gone once I start to really understand it.
mikey250Author Commented:
i dont mind because it is going anyway as i am aware that 'mpls' has took over but not yet configured one yet but i will have to also do this.
mikey250Author Commented:
sound advice.
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