How to route subnets?

libblibb Member Posts: 1 ■□□□□□□□□□
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?

Comments

  • mzinzmzinz Member Posts: 328
    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?
    _______LAB________
    2x 2950
    2x 3550
    2x 2650XM
    2x 3640
    1x 2801
  • Forsaken_GAForsaken_GA Member Posts: 4,024
    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_GAForsaken_GA Member Posts: 4,024
    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.
Sign In or Register to comment.