1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

see the modem

Discussion in 'DD-WRT Firmware' started by R0ut3r, Feb 17, 2006.

  1. R0ut3r

    R0ut3r Network Guru Member

    is there a trick to see a modem (http interface) connected to the wan port of a dd-wrt router from the lan side? :thumb:
     
  2. 4EverGreen

    4EverGreen Network Guru Member

    See the solution in 4Access posts here and here. :thumb:
     
  3. R0ut3r

    R0ut3r Network Guru Member

    i suppose that's possible, thanks a lot to u and 4access :thumb:
    i will try it! :rockon:
     
  4. R0ut3r

    R0ut3r Network Guru Member

    i'm trying just now.. but i'm not sure for the commands

    my wrt have a 192.168.0.1 ip, 255.255.255.0 netmask, all the pcs has 192.168.0.x ip
    i have changed the modem ip to its default 192.168.1.1

    so..
    the commands reported by 4access
    Code:
    ifconfig vlan1:0 192.168.0.2 netmask 255.255.255.0
    iptables -t nat -I POSTROUTING -o vlan1 -d 192.168.0.0/24 -j SNAT --to-source 192.168.0.2
    became, with my configuration
    Code:
    ifconfig vlan1:0 192.168.1.1 netmask 255.255.255.0
    iptables -t nat -I POSTROUTING -o vlan1 -d 192.168.1.0/24 -j SNAT --to-source 192.168.1.1
    is that true??

    another question.. these commands can cause a security problem or not? (this isnt' a bank :) but i don't want to open an highway to my pc)

    thanks again..
     
  5. 4EverGreen

    4EverGreen Network Guru Member

    Wrong ...

    If you read carefully 4Access's notes you'll understand that the first command assigns a second IP to the WAN port ...

    So, if your modem is 192.168.1.1 you don't want to assign this same IP to the wan port of your WRT ... instead you should assign a different IP from the modem's subnet :
    ifconfig vlan1:0 192.168.1.2 netmask 255.255.255.0
    iptables -t nat -I POSTROUTING -o vlan1 -d 192.168.1.0/24 -j SNAT --to-source 192.168.1.2


    Furthermore, if you read the 2 last posts in this thread
    you'll want to try it without the second command ...

    With this alone, there are no security problems whatsoever.

    Cheers :)
     
  6. mstombs

    mstombs Network Guru Member

    Thanks Guys, for the benefit of others searching for the same thing I can confirm that the command

    ifconfig vlan1:0 192.168.100.2 netmask 255.255.255.0

    entered via RUN command on a WRT54GS v1.1 running firmware

    v4.70.8, Hyperwrt 2.1b1 + Thibor13d

    allows Robin Walker's docsdiag program with default parameters to access my Terayon TJ210 cable modem docsis diagnostics (no http diag screen) in client side mode (ISP NTL blocks SNMP from ISP side) via the router. This modem responds to requests on 192.168.100.1, the router has LAN side default IP 192.168.1.1.
     

Share This Page