passing multiple public IP addresses through 2 routers

Discussion in 'Cisco' started by lombardi, Jun 10, 2004.

  1. lombardi

    lombardi Guest

    Hello group,

    We have a router with two ethernet interfaces. The internal interface
    is on a 192.168.1.0 network. The external interface has a public IP
    address and is connected to a DSL modem. We have I believe 15 public
    IP addresses from our ISP. What we want to do is install another
    router behind the internal interface of the existing router and pass
    10 of these public ip addresses to clients located behind the internal
    interface of the new router. We cannot change the private addressing
    sceme of the internal interface of the first router. My question is
    how do we assign the new router a public ip address for the external
    interface and statically map the 10 public ip addresses to pcs located
    behind the internal interface of the first router. Looks like this;

    24.56.45.98
    Exisisting 1711 router
    192.168.1.30
    |
    |
    |
    |
    ???.???.???.??? (should be Public IP
    Address)
    New 1711 router
    172.16.50.1
    |
    |
    10 PCs that need public IP static mappings for vpn clients

    Is there a way to pass thoses 10 public ip addresses to the 10 pcs
    that need them for an older VPN client that does not support NAT-T.

    Thank you very much for any help. I hope I was descriptive enough.

    Joe
    lombardi, Jun 10, 2004
    #1
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  2. In article <>,
    (lombardi) wrote:

    > Hello group,
    >
    > We have a router with two ethernet interfaces. The internal interface
    > is on a 192.168.1.0 network. The external interface has a public IP
    > address and is connected to a DSL modem. We have I believe 15 public
    > IP addresses from our ISP. What we want to do is install another
    > router behind the internal interface of the existing router and pass
    > 10 of these public ip addresses to clients located behind the internal
    > interface of the new router. We cannot change the private addressing
    > sceme of the internal interface of the first router. My question is
    > how do we assign the new router a public ip address for the external
    > interface and statically map the 10 public ip addresses to pcs located
    > behind the internal interface of the first router. Looks like this;
    >
    > 24.56.45.98
    > Exisisting 1711 router
    > 192.168.1.30
    > |
    > |
    > |
    > |
    > ???.???.???.??? (should be Public IP
    > Address)
    > New 1711 router
    > 172.16.50.1
    > |
    > |
    > 10 PCs that need public IP static mappings for vpn clients
    >
    > Is there a way to pass thoses 10 public ip addresses to the 10 pcs
    > that need them for an older VPN client that does not support NAT-T.
    >
    > Thank you very much for any help. I hope I was descriptive enough.


    There's no need to put a public IP on the new router, it should have an
    address in the 192.168.1.0/24 network.

    On the router that connects to the Internet, configure static NAT
    entries that map the 10 public IP's to addresses in the 172.16.50.0/24
    address block, and configure a static route for 172.16.50.0/24 pointing
    to the new router's 192.168.1.x address.

    --
    Barry Margolin,
    Arlington, MA
    *** PLEASE post questions in newsgroups, not directly to me ***
    Barry Margolin, Jun 10, 2004
    #2
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  3. lombardi

    lombardi Guest

    Barry Margolin <> wrote in message news:<>...
    > In article <>,
    > (lombardi) wrote:
    >
    > > Hello group,
    > >
    > > We have a router with two ethernet interfaces. The internal interface
    > > is on a 192.168.1.0 network. The external interface has a public IP
    > > address and is connected to a DSL modem. We have I believe 15 public
    > > IP addresses from our ISP. What we want to do is install another
    > > router behind the internal interface of the existing router and pass
    > > 10 of these public ip addresses to clients located behind the internal
    > > interface of the new router. We cannot change the private addressing
    > > sceme of the internal interface of the first router. My question is
    > > how do we assign the new router a public ip address for the external
    > > interface and statically map the 10 public ip addresses to pcs located
    > > behind the internal interface of the first router. Looks like this;
    > >
    > > 24.56.45.98
    > > Exisisting 1711 router
    > > 192.168.1.30
    > > |
    > > |
    > > |
    > > |
    > > ???.???.???.??? (should be Public IP
    > > Address)
    > > New 1711 router
    > > 172.16.50.1
    > > |
    > > |
    > > 10 PCs that need public IP static mappings for vpn clients
    > >
    > > Is there a way to pass thoses 10 public ip addresses to the 10 pcs
    > > that need them for an older VPN client that does not support NAT-T.
    > >
    > > Thank you very much for any help. I hope I was descriptive enough.

    >
    > There's no need to put a public IP on the new router, it should have an
    > address in the 192.168.1.0/24 network.
    >
    > On the router that connects to the Internet, configure static NAT
    > entries that map the 10 public IP's to addresses in the 172.16.50.0/24
    > address block, and configure a static route for 172.16.50.0/24 pointing
    > to the new router's 192.168.1.x address.


    Barry,

    You've been most helpful. Also nice to have an MIT alumni help out.

    Thanks
    lombardi, Jun 10, 2004
    #3
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