linksys router with different subnet

Discussion in 'Cisco' started by Patriot, Nov 1, 2003.

  1. Patriot

    Patriot Guest

    Can someone please shed some light. I have a cable modem with two linksys
    routers, one is a 4 port linksys/VPN router and the other is a 8 port. I
    want to link and configure them with a different subnet. For example, the 4
    port will use 192.168.1.1 255.255.255.0 and the 8 port with 192.168.2.1
    255.255.255.0. How can I configure them correctly and still access the
    internet from both.

    Thank you very much
     
    Patriot, Nov 1, 2003
    #1
    1. Advertisements

  2. Patriot

    Kevin© Guest

    A tad off topic for a Cisco group but here goes .. ;-) This sounds like an
    exam question.

    4 Port Linksys = L4
    8 Port Linksys = L8
    Cable Modem = CM

    Assumptions;
    Cable modem will NOT give out more then one DHCP assigned address from your
    ISP.
    You know the DNS's given out by your ISP.
    You have enough cross over cables, etc.
    Here's how I would configure them.

    CM -> L4 -> L8.

    * CM connected to L4's WAN port.

    * L4 (port 1) is connected to WAN port on L8
    * L4 LAN address is 192.168.1.1,
    * L4's DHCP server set for 192.168.1.101-103.
    * Set L4's DNS to ISPs.
    * Leave PCs you want to VPN into on L4's LAN.


    * L8's WAN port is set for STATIC IP and set to 192.168.1.254
    * L8's Default gateway is 192.168.1.1.
    * L8's LAN address is 192.168.2.1
    * L8's DHCP server set for 192.168.2.101-108.
    * Set L8's DNS to ISPs.
     
    Kevin©, Nov 2, 2003
    #2
    1. Advertisements

  3. Patriot

    Patriot Guest

    I truely appreciate your help. I will try it. Again thank you very much
     
    Patriot, Nov 2, 2003
    #3
  4. Patriot

    Patriot Guest

    Kevin,
    why the PC connected to L8 is pointing to default gateway 192.168.2.1
    instead of 192.168.1.1. In the L8 router I change the default gatway to
    192.168.1.1 but every time I renew and release the pc that I connect in one
    of the port in L8, it keeps pointing to 192.168.2.1. Shouldn't it be
    pointing to the L4 gatway 192.168.1.1.

    Thanks in advance
     
    Patriot, Nov 2, 2003
    #4
  5. Patriot

    Patriot Guest

    What I am doing wrong. I can ping the default gateway 192.168.1.1 in L4 from
    any computer that is connected to L8 but I can't ping the DG 192.168.2.1 in
    L8 from L4 router.

    Any help will be greatly appreciated

    Thanks
     
    Patriot, Nov 2, 2003
    #5
  6. Patriot

    Kevin© Guest

    Hi.

    L8 devices can PING anything inside 192.168.1.x, good. Can L8 and L4 PCs
    reach the Internet?

    Since the PCs on the L8's LAN know their default gateway which 192.168.2.1,
    L8 forwards the packets onto L4s network. All is well for them outbound.
    Your now having issues inbound to L8's LAN.

    These Linksys devices are pretty simple. They probably don't have a section
    for adding custom routes or even do ICMP redirection. As a result L4's LAN
    PCs don't know anything about the 192.168.2.x segment, they simply see
    traffic looking like it's coming from 192.168.1.254 (NAT'ed PCs in
    192.168.2.x).

    On the L8 can you switch off NAT and only have it route? I'll be buying
    one of these soon, once I sell my old SMC. I'm not that familiar with the
    LinkSys in terms of setting up STATIC NATs (making say 192.168.2.101 NAT to
    192.168.1.201, for example.). But you 'may' need to STATIC NAT each PC on
    L8 in order for them to be seen properly by L4 PCs.

    I'm assuming Microsoft PCs here. One thing you can try is on a PC in
    192.168.1.x add a manual route towards 192.168.2.x. You'll need to go into
    the PC and add a route adjustment from a command prompt.

    route add 192.168.2.0 mask 255.255.255.0 192.168.1.254

    This tells the L4 PC that to reach the 192.168.2.x network, they need to
    talk to 192.168.1.254 (L8's WAN port). The question is will L8 allow them
    in? It things 192.168.1.x as untrusted on the WAN interface.

    What you may need to consider if this gets too complicated or isn't adequate
    for your needs, this may not even work right, is to pick up a cheap 8 port
    switch and hang it off one of L4's LAN ports.
     
    Kevin©, Nov 2, 2003
    #6
  7. Patriot

    Kevin© Guest

    Sorry missed this.

    L8 is the router for L8's PCs. He's the default gateway for L8's PCs.
    They have to have 192.168.2.1 as their gateway.

    He'll forward or route the traffic from L8's PC's out his WAN port onto his
    default gateway which is L4, or 192.168.1.1. L4 then sends it to the
    Internet.
     
    Kevin©, Nov 2, 2003
    #7
  8. Patriot

    Patriot Guest

    Thanks a lot. Yes I can get in to the internet with any port from both L4
    and L8. I will try the second solution for the pinging and let you know.

    Thanks for all your help
     
    Patriot, Nov 2, 2003
    #8
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.