Wireless laptop IP is different than what router sees

Discussion in 'Wireless Internet' started by john22, Jul 13, 2006.

  1. john22

    john22 Guest

    I have a laptop connected to internet through a wireless router. When I
    do ipconfig on the laptop it shows 192.168.0.3. However, the user list
    on the router web interface doesn't have this IP. Instead, the list
    shows 192.168.1.1, 192.168.1.2 and 192.168.1.3. Some of these IPs
    correspond to other wired PCs on the same network. TCP/IP settings on
    the laptop obtain IP address and DNS server automatically.

    Basically, I am trying to setup a ftp server on my wireless laptop at
    home but to be able to do that the router needs to see this laptop
    correctly after which I can forward ports 20-21 to the laptop's IP.

    This works perfectly if I "wire" the laptop to the router. The laptop
    gets 192.168.1.4 and the router's user list show the same IP as well.
    So it all makes perfect sense when the laptop is wired. I am not sure
    how to get this to work for wireless connection. I have been fiddling
    with this for a few days now, any pointers will be greatly appreciated.

    Thanks,

    John22
     
    john22, Jul 13, 2006
    #1
    1. Advertisements

  2. john22

    Duane Arnold Guest

    You should be using a static IP on the router and not a DHCP IP from the
    router when doing the above, because if those ports are forwarded to a
    machine using a DHCP IP, the IP might change and the forwarding rules
    will not work any more.
    Configure the wireless NIC to use a static IP on the router.

    Duane :)
     
    Duane Arnold, Jul 13, 2006
    #2
    1. Advertisements

  3. john22

    David Guest

    Are you are sure you are connected to YOUR wireless network and not some
    other access point?

    David
     
    David, Jul 13, 2006
    #3
  4. john22

    Duane Arnold Guest

    You got a point there.

    Duane :)
     
    Duane Arnold, Jul 13, 2006
    #4
  5. john22

    john22 Guest

    I am connected to mine. I confirmed it by matching with the external IP
    address.
     
    john22, Jul 13, 2006
    #5
  6. john22

    john22 Guest

    I am connected to mine. I confirmed it by matching with the external IP
    address.
     
    john22, Jul 13, 2006
    #6
  7. john22

    john22 Guest

    Thank you for your resonse!

    1) When I wired the laptop and still used DHCP, I could get my ftp
    server to work. Although, I understand with dynamic IP this should stop
    working as soon as the IP changes since all forwarding rules will no
    longer hold. However, it should work atleast for one session. Moreover,
    the laptop seems to get the same dynamic IP address everytime.i.e.
    192.168.0.3.

    2) When I do run->cmd->arp -a the table shows the following (if that
    is relevant here):

    Interface: 192.168.0.3 --- 0x2
    Internet Address Physical Address Type
    192.168.1.1 00-03-47-b1-99-3d dynamic
    The user list on router's web interface shows 192.168.1.1 as one of the
    IPs.

    3)Without changing router settings, when I setup TCP/IP properties on
    the laptop to use static IP (like 192.168.1.6 or sth) and DNS the
    internet stops working. But if I setup the IP to 192.168.0.3 the static
    addressing works and so does the internet. How do I setup the router
    for static addressing? Is it possible to use static addressing for the
    laptop and dynamic addressing for other computers at the same time?

    Thanks for any help!

    John22
     
    john22, Jul 13, 2006
    #7
  8. Could you post the result of "ipconfig /all"?
    DHCP knows about 'manual DHCP', registering a mac address to use a
    'fixed' IP address. Of course, you always could assign an IP address
    on your laptop outside the DHCP pool.

    Could it be that your router has all wired PCs on a different LAN
    than the wireless ones? Maybe VLAN tagging?
    Yes, it is.

    Peter
     
    Peter Boosten, Jul 13, 2006
    #8
  9. john22

    Rico Guest

    What brand of Wireless Router are you using, DLink? (model and firmware
    also if you could). Just for reference sake. Also when you Open Avaialbe
    Wirelss networks, do any others besides yours show up?
    fundamentalism, fundamentally wrong.
     
    Rico, Jul 13, 2006
    #9
  10. john22

    Duane Arnold Guest

    What external IP? If the machine is using a DHCP IP on the router as you
    claim, then the machine wireless NIC MAC would be linked to an IP in the
    router's DHCP table, when you look at the table.

    Duane :)
     
    Duane Arnold, Jul 14, 2006
    #10
  11. john22

    John Navas Guest

    There's no such thing as an "external IP address" on a NAT client.

    What you should be doing is using a *unique* SSID (e.g., "john22net")
    that's set in the wireless client, not the default SSID from the router
    manufacturer.
     
    John Navas, Jul 14, 2006
    #11
  12. john22

    john22 Guest

    I am using TrendNet TW100-S4W1CA.

    By external IP I meant the router's external IP. Your ISP assings an
    external IP to your router (the IP that rest of the world sees). All
    computers on a private network sharing the external IP would show same
    IP when you go to www.whatismyip.com. If mistakenly you get connected
    to someone else's wireless network then www.whatismyip.com should not
    match with that of other computers. This is how I confirmed I was using
    "my" wireless connection.

    Here is my iconfing /all
    Windows IP Configuration

    Host Name . . . . . . . . . . . . : John
    Primary Dns Suffix . . . . . . . :
    Node Type . . . . . . . . . . . . : Unknown
    IP Routing Enabled. . . . . . . . : Yes
    WINS Proxy Enabled. . . . . . . . : Yes
    DNS Suffix Search List. . . . . . : Domain

    Ethernet adapter Wireless Network Connection:

    Connection-specific DNS Suffix . : Domain
    Description . . . . . . . . . . . : Dell TrueMobile 1300 WLAN
    Mini-PCI
    ard
    Physical Address. . . . . . . . . : 00-90-4B-24-8B-BD
    Dhcp Enabled. . . . . . . . . . . : Yes
    Autoconfiguration Enabled . . . . : Yes
    IP Address. . . . . . . . . . . . : 192.168.0.3
    Subnet Mask . . . . . . . . . . . : 255.255.255.0
    Default Gateway . . . . . . . . . : 192.168.0.1
    DHCP Server . . . . . . . . . . . : 192.168.0.1
    DNS Servers . . . . . . . . . . . : 192.168.1.254
    68.87.76.178
    68.87.78.130
    Lease Obtained. . . . . . . . . . : Thursday, July 13, 2006
    7:32:55 PM
    Lease Expires . . . . . . . . . . : Monday, January 18, 2038
    8:14:07 PM

    Many thanks everybody for your responses!
     
    john22, Jul 14, 2006
    #12
  13. john22

    Duane Arnold Guest

    If that NIC's MAC is not listed in the router's admin DHCP server screen
    as you say that's an IP issued by your router, then your machine is not
    using your router.

    Is the MAC linked to 192.168.0.3 listed in the router's admin DHCP
    server screen?

    Physical Address. . . . . . . . . : 00-90-4B-24-8B-BD

    I find it hard to believe that wire machines are using 192.168.1.xx
    while this one lone wireless machine is using 192.168.0.xx from the DHCP
    server on the router.

    Duane :)
     
    Duane Arnold, Jul 14, 2006
    #13
  14. john22

    john22 Guest

    It seems there are two routers:

    Router #1: TrendNet TW100-S4W1CA is directly connected to cable modem.
    I think this router doesn't have wireless capability.

    Router #2: NetGear Wireless Router MR814 which is wire/wireless combo.
    The laptop is connected to the internet via router #2. This router is
    hooked up to Router #1 and gets IP = 192.168.1.1 which shows up on DHCP
    list of router #1.

    The IP address of the laptop 192.168.0.3 shows on the DHCP table of
    Router #2.

    In this scenario how do we forward the ports now that there are two
    routers between the cable modem and the laptop. Do I need to forward
    ports on router #1 to router#2 and then from router#2 to the laptop?

    Thanks in advance,

    -John22
     
    john22, Jul 14, 2006
    #14
  15. john22

    DavidT Guest

    what is the ip address of your broadband modem??
    Could be the modem somehow assigning a ip addess if it is capable of being a
    DHCP server
     
    DavidT, Jul 14, 2006
    #15
  16. Router #2 should NOT have a DHCP table, disable the DHCP server on it,
    and everything will work.

    You can't have two DHCP servers on one network, at least not without
    grief.
    Router #2 isn't acting as a router, its just being a wireless access
    point and wired hub. Make sure DHCP is disabled on it, otherwise do
    all your port forwarding on the router connected to the internet.
     
    Mark McIntyre, Jul 14, 2006
    #16
  17. john22

    Rico Guest

    What brand of Wireless Router are you using, DLink? (model and firmware
    also if you could). Just for reference sake. Also when you Open Avaialbe
    Wirelss networks, do any other networks in addition to yours show up?

    fundamentalism, fundamentally wrong.
     
    Rico, Jul 14, 2006
    #17
  18. john22

    John Navas Guest

    It actually looks like he is doing double NAT, which is a Very Bad Idea.
    It takes more than turning off DHCP to convert a wireless router into an
    access point -- see the wikis below.
     
    John Navas, Jul 15, 2006
    #18
    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.