How to route subnets?

I came across a request from a client at work and thought I'd ask for some help solving it while I study for my ccnp.

He would like his public facing router to be assigned one of our public IP's from a /30.

Then behind that router he would to be given one of our /29's for one of his networks, and a /28 for another one of his networks.

Normally, we create a Vlan on our main cisco router and make the first useable IP of a customers subnet, their gateway.

How would I solve this?

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Comments

mzinz

libb wrote: »

I came across a request from a client at work and thought I'd ask for some help solving it while I study for my ccnp.

He would like his public facing router to be assigned one of our public IP's from a /30.

Then behind that router he would to be given one of our /29's for one of his networks, and a /28 for another one of his networks.

Normally, we create a Vlan on our main cisco router and make the first useable IP of a customers subnet, their gateway.

How would I solve this?

A little confused what you're trying to do... Maybe draw a picture? Are you trying to just use ONE IP from the /29 and /28 blocks?

Forsaken_GA

libb wrote: »

I came across a request from a client at work and thought I'd ask for some help solving it while I study for my ccnp.

He would like his public facing router to be assigned one of our public IP's from a /30.

Then behind that router he would to be given one of our /29's for one of his networks, and a /28 for another one of his networks.

Normally, we create a Vlan on our main cisco router and make the first useable IP of a customers subnet, their gateway.

How would I solve this?

Easy, create a static route.

lets say the address of the /30 is 10.0.0.0/30 with his remote IP being 10.0.0.2

lets say his /28 is 172.16.1.0
lets say his /29 is 192.168.1.0/29

On your router, you would create static routes like this:

ip route 172.16.1.0 255.255.255.240 10.0.0.2
ip route 192.168.1.0 255.255.255.248 10.0.0.2

You'll have a route in your routing table for the /30, so whenever traffic hits your network, it just needs to know the next hop. Use a static route to point that to the next hop.

Presumably, once the traffic hits his routers, they'll have been setup propelry to know what to do with it.

Forsaken_GA

Oh, and while I'm thinking about it, there is absolutely no reason to use public IP's for the /30, RFC 1918 addresses work just fine.

If the customer insists on public IP's for the /30, the customer is an idiot, and make sure he's charged accordingly.