Cisco switch help for Newbie

Posted on 2012-09-07
Last Modified: 2012-09-12

I am very green when it comes to Cisco.  I have an old 4503 switch and a C3560 switch that will share a fiber connection via gigabit uplinks.

One network is /23 - and the other is /23
The only internet connection (which both need is at :

Can someone tell me the best way to configure the interfaces?  

Thank you so much in advance!
Question by:pcassine
    LVL 3

    Expert Comment

    by:Nathan Kaufman
    The host range for your network is - and since is outside that range, you are not on the same network.  The only way to communicate between multiple networks is with a Router.  How many hosts are needed?  It seems to me that if you only have those two switches, than you don't need 510 hosts per network.  Which is what the /23 provides.  You could probably get away with having everyone on the /23 network.  If you do however need those two network address schemes than you need a router for them to talk, or a layer 3 switch.

    Author Comment

    Hi Nate_IT,

    I think both of the switches in question are layer 3.  Unfortunately we need to utilize the subnet mask as is.

    Can you tell me how we could configure the gig interfaces between the two switches to make the two networks communicate?

    Thank you so much!
    LVL 50

    Expert Comment

    by:Don Johnston
    What's the topology? Which switch will have the internet connection? Will one of your networks be connected to the 4503 and the other network connect to the 3560? Is the internet handoff an ethernet connection? If so, what speed?
    LVL 1

    Accepted Solution

    It is simple.

    4503 config mode

    ip routing

    int vlan 1
    ip address

    int vlan 2
    ip address /23

    int gig1/0
    description connected 3560
    switchport mode trunk  

    go to 3560

    just make vlan 2 and make member access port which you want in range
    and make put default gateway in end device then it will work with  network

    config mode
    ip default gateway

    int g1/0
    switch mode trunk

    Author Closing Comment

    Thank you very much!

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