There are essentially 2 ways of setting up Frame Relay.
- Multi-point/Static Map
- Pros – Uses less IP addresses
- Cons – Seems to be a mish-mosh way of putting things together.
*NOTE* – The preferred way of setting up Frame Relay is Point-to-Point/Sub-interfaces but requires more IP addresses.
As you can probably tell from the title we will be covering Multi-Point. Multi-point is also sometimes called “static mapped” because you essentially have to go in and statically map information otherwise things just will not work. Multi-point is _____FIND-THIS-OUT________ typology.
Technology terms that might be thrown around:
- Frame Relay is a layer 2 technology just like Ethernet is a layer 2 technology. Similarly like Ethernet Frame Relay needs to have layer 2 addresses. In frame relay the layer 2 addresses are called DLCI
- LMI – is a protocol (language) that delivers a list of DLCIs between routers. LMI is run on the service provider network/cloud.
I’m am going to be using Packet tracer to setup this lab.
First let’s put a cloud and 3 generic routers in the work area. Let’s label them as well. It should look something similar to this:
Next it’s important that we setup the serial connections. We must make sure the DCE is always connected starting at the “cloud” and then dragged and connected to the router. I will start with R1 and Finish with R3. hover over the connections to make sure that DCE’s are all on the cloud side. DTE’s will always be the client routers.
Next let’s label the map. Labelling and planning Frame Relay is half the battle. I find if I don’t do this next step I have a really hard time with the rest of the setup.
Next it’s important that we specify the path from each router to the other routers using DLCIs. They are pronounced DELL-SEES. It’s typical for people to write these using this format:
If this is your first time seeing this that probably won’t make much sense. People normally try and name DELCIs based on the path. To interpret them the first number is normally the number of the local router and the last number is the router where it is going to. You would read “102” as “router 1” TO “router 2”. 301 would be read as “router 3” to “router 1”. It’s typical that each router will have a single DELCI but will have several mappings to other DELCIs.
Next we will need to program the IP addresses on the router network interfaces. I like writing this out in Notepad++ and then copying it into the terminal line. We’ll also include the RIP commands.
Click on the cloud and let’s configure it. We’re going to leave LMI set to cisco’s version:
Serial 0 –> IE. Line going to R1
Serial 1 –> IE. Line going to R2
Serial 2 –> IE. Line going to R3
Next we need to setup the Frame Relay section of the cloud:
I think the last screenshot might need some explaining. When configuring Frame relay I always pick one router and use it as the starting point. The first two lines use Serial 0 as the starting point. Each line describes how to get to other networks using DLCIs.
Next we will have to add the static DLCI commands on each router to get everything all working…