Creating multiple point to point connection

[Nukesquad]

Consider me mostly a newbie. I have a router that's connected to a WiFi radio system. The radio is, for all intent and purposes, transparent to the network.

Point is now, I want to connect via the same WiFi radio system to 4 other routers (each other router has the same radio system) on a point to point basis.

All five routers have static IPs.

The need is to create 4 static point-to-point link, over 1 single interface on the router that's connected to the radio system.

Can this be done? Is so, how? Help please?

[lgijssel]

First of all, I do not really see the advantage of configuring this as point-point. Appearently you want to make all traffic flow over the central router? The radio is actually a point-to-multipoint medium by nature. This means that the bandwidth on the link will be shared, no matter what you configure.

You could "enforce" point-point behaviour by means of static routing. On all spoke-routers you configure a single static route 0.0.0.0 with the hub router as the next hop.

On the the central router you can then put statics to the respective destinations. Very important is to use the interface command "no ip redirects"

This prevents icmp redirects being sent which would cause non-point-to-point behaviour. This implies that you have used the same ip subnet for all routers. This is what I would configure for this case.

Alternatively, you may use different subnets per router and apply secondary IP's on the hub.

Regards,

Leo

[Nukesquad]

I understand that there is no benefit here. Let's just say there's an underlining issue that can be solve if I do this.

So technically, I can use multiple static IPs on the hub router and enforced it with static routing?

[jackyoung]

What I think we can use GRE tunnel to create the tunnels between hub and spokes, and the Wi Fi use the same subnet in all locations.

Does it make sense ?

[Nukesquad]

Ah, maybe I didn't explain it well enough.

Its like this, I need to create point-to-point link between hub router and spoke router. That's not really clear as there's really no route here.

What I meant to say is that say the 4 spoke routers have the same subnet, and have IP addresses of x.x.x.16, x.x.x.18, x.x.x.20, x.x.x.22.

I need to config the hub router to have x.x.x.17, .19, .21, .23 from which x.x.x.16 to x.x.x.17 is a fixed pair and so on so forth.

So essentially, if I packet needs to go to x.x.x.16 router, it'll need to arrive at x.x.x.16 from the hub router saying that its last hop was from x.x.x.17.

If a packet wants to go to router x.x.x.23, it'll arrive there thinking it passed through x.x.x.22.

II'm quite sure its possible but not sure how.

[jackyoung]

You can configure secondary IP address in the hub router, but what I mentioned is to configure one IP in hub router physical interface then configure 4 tunnel interfaces for individual spoke routers. It should provide the same function.

[lgijssel]

A router is a fairly stupid thing. You can fiddle a lot by selectively distributing routes.

In the suggested solution, the hub router is the only one who knows the routes to all destinations. The spokes can only forward traffic to their next hop which is the central hub.

This is typical point to point behaviour.

Regards,

Leo

[Nukesquad]

Really appreciate the help, but I'm not sure you're not getting what I want to do.

I want to make it so that if I remove the x.x.x.17 from the interface, one of my router (x.x.x.16) will no longer forward traffic to the hub router.

Someone told me I need to set up a point to point link for this, with one point of the pair being on the spoke and the other on the hub router. I check out point to point and I keep getting references to frame relay. Is that what I need to do?

I'm thinking the first suggestion with all spoke routers being on different subnets and then with multiple secondary address on the single physical interface would work. However, I may not have that many subnets to go around.