Duplicate LAN site IP, connecting site to site T-1 for video

Posted on 2011-05-02
Last Modified: 2012-05-11
My internal LAN ip's are set to 192.168.x.x and we have seprate video/data T-1 lines in a hub to site to site T-1 connections.  I want to connect to another company that has the same internal IP setup that we have.  I need to setup a T-1 line from their site to ours and then be able to dial from a 192.168.x.x to a 192.168.x.x.  I can not change my internal IP scope as we use that video to do multiply video to other sites that have different IP's that work.
Question by:marcelgar
    LVL 9

    Expert Comment

    Setup the connection between the two through a bridge.  The only issue there is there can be no duplicate IPs on both sides.

    What is the third octet of the address, since the 198 addresses are class C and will route as long as the 3rd octet is different and the netmask is set to
    LVL 5

    Expert Comment

    It sounds like you need to ROUTE between subnets using a /24 subnetmask (  However, you did not indicate what the 3rd octet is, is it 192.168.1.x, 192.168.2.,x etc....and is that 3rd octet the same for BOTH networks?

    if it IS the same for both networks, either one of you has to change, OR you can do POLICY NATTING, where  you assign a new IP for resources on the other side, and the routers will take care of NATTING.  

    This means that if you are both, and you need to access resource on the remote end, you would map a NEW subnet scheme and IP (say, and setup the configuration to NAT to on the other end.  Likewise, with this in place, the other side would ALSO need a NAT policy in place with a new unique subnet to talk BACK to your resources, (say

    Please let me know if the subnets are both the same in the 3rd octet, and if you want to setup something like a policy nat.  It gets messy if you do not document it correctly or set it up right, but if setup and managed correctly, this can allow (2) LANs to connect to each other while still running on the same private IP subnet.

    Author Comment

    The 3rd octet is the same, I am thinking of settin one aside that we will not use in the future like
    and the other site acn set up one like
    LVL 5

    Accepted Solution

    That would work, then use policy NAT to NAT to specific resources.  This will be easy if you only have only a few resources that need to be accessed from both sites, just setup NAT policies and DNS mappings to access them across the links.  

    Author Closing Comment

    Thanks so much for quick response.

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