how do I allow two subnets to see each other

Posted on 2007-10-13
Last Modified: 2010-04-11
how do I allow two subnets the computer on each

Question by:kinosabi
    LVL 2

    Expert Comment

    This question isn't entirely clear.  Are you trying to get computer A on subnet1 to talk to computer B on subnet2?  If so, you need something, like a router, to route between the two subnets.

    Author Comment

    I have two routers, one is subnet (A) the other is subnet (B), Subnet(A) is the parent, and Subnet(B) is connected through SubNet(A) at  I have no problem with computers on subnet(B) seeing computers on Subnet(A).  I want for computers on subnet(A) to see computers on subnet (B).  
    LVL 70

    Expert Comment

    If you want two differnet subnets to be able to communicate with each other you need to route between the two using a hardware router or a computer configured with two network cards and configured to route between the two.


    Author Comment

    What I have is two routers, I want computers on one router to see the computers on the other router, and in the opposite direction  I just need to know the routes that need to be on each router to allow each routers computers to see each other
    LVL 2

    Accepted Solution

    Each router has (at least) 2 interfaces in separate subnets.  There should be a network between these two routers. eg.

    PC A------ int 1 (router1) int 2 ------ int 1 (router2) int 2 ------ PC B

    so PC A and int 1 on router1 is in one network (subnet)
    PC B and int 2 on router2 is on another network (subnet)
    int2 on router1 and int1 on router2 is on yet another network (subnet)

    you will tell router1 that the route to network containing PC B is via the IP address of int1 on router2.  Same with router2, that is the network PC A is on is reachable via the IP address of int2 on router1

    on a cisco, this would be

    ip route

    Assuming PC B is on / 24 network and the network between the routers is and int1 on router2 is

    Does that help?  If not, please let us know what exactly you are trying to do in the environment. -T


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