LAN connection present but no internet connection

By bhbf
Jan 14, 2011
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  1. I'm using a Dell Precision 490 and recently had the entire computer wiped due to viruses, had the OS reinstalled and am in the process of setting it up again. I have connected to the LAN at my office but can't get the computer to connect to the internet and all the built in troubleshooters and diagnostic tests can't find anything wrong with the connection. I have manually entered the IP and Gateway addresses and the DNS addresses for our network but still can't connect. Any ideas?
  2. mailpup

    mailpup TS Special Forces Posts: 6,875   +332

    After the OS was installed did anyone install the chipset, LAN, sound, graphics, etc. drivers?
  3. bhbf

    bhbf TS Rookie Topic Starter

    I believe that all the appropriate drivers have been installed, yes.
  4. jobeard

    jobeard TS Ambassador Posts: 8,945   +584

    use the device mgr to verify that
  5. bhbf

    bhbf TS Rookie Topic Starter

    Yes, the drivers are installed, according to the device manager.
  6. jdillman1502

    jdillman1502 TS Enthusiast Posts: 120

    You may want to check the following:

    For Internet Explorer
    -Open IE
    -Click Tools
    -Select Internet Options
    -Select the Connections Tab
    -Click LAN Settings at the bottom of the screen
    -Make sure the box "Use a proxy server for your LAN" is not checked

    For Firefox
    -Open Firefox
    -Click Tool
    -Select Options
    -Select Advanced (top right)
    -Select the Network Tab
    -Click the Setings button
    -Make sure No Proxy is selected
  7. bhbf

    bhbf TS Rookie Topic Starter

    I've doubled checked these settings for internet explorer and the problem is still persisting.
  8. jobeard

    jobeard TS Ambassador Posts: 8,945   +584

    Using run->cmd enter ipconfig /all
    your IP is at IP Address. . . . . . . . . . . . : 192.168.x.x
    the router will be at Default Gateway . . . . . . . . . : 192.168.a.b.
    and the DNS at DNS Servers . . . . . . . . . . . :a.b.c.d​
    Q: does your system access the router?
    test: ping 192.168.a.b

    Q: can you access your DNS?
    test: ping a.b.c.d

    Q: can you ping google using the address?
    test: ping

    Q: now can you resolve a name to an address?
    test: nslookup
    yes, there's a period trailing .com
  9. bhbf

    bhbf TS Rookie Topic Starter

    The system is accessing the router but can't access the DNS.
  10. jobeard

    jobeard TS Ambassador Posts: 8,945   +584


    lookup name -> address will fail and that stops all email/browser activities.

    Did this ever work on this system or is this a new ISP connection or New system?

    Let's take some inventory:
    the OS and edition,
    eg Windows/XP/Pro Vista/Home Win/7 ultimate

    WHY??? delete that stuff and allow the system to pull the data from the router using DHCP.
  11. bhbf

    bhbf TS Rookie Topic Starter

    I'm working on Windows XP.

    And the only reason that I manually entered in the IP and DNS is because when I let the system obtain them automatically, then my computer doesn't connect to the LAN.
  12. jobeard

    jobeard TS Ambassador Posts: 8,945   +584

    manual config is frought with issues and just one will cause problems.

    highly recommend using DHCP and let your system be configured from the router settings.
    if issues are still present, we can address those and then all your systems will be controlled from a single point (the router) and can be maintained uniformly
  13. bhbf

    bhbf TS Rookie Topic Starter

    I've reset the IP and DNS to be chosen by the system automatically. I still can't connect to the internet or the LAN but the system is recognized the router when I ping it. I can't find the automatic DNS though and it doesn't show up when I type "ipconfig /all" into the command prompt.
  14. jobeard

    jobeard TS Ambassador Posts: 8,945   +584

    Q? did you recently add the router? if so, there's a setting required by the ISP
  15. bhbf

    bhbf TS Rookie Topic Starter

    Well, the system was recently wiped and then the OS was reinstalled. Would that make the router new to the system?
  16. jobeard

    jobeard TS Ambassador Posts: 8,945   +584

    no. I was headed toward the frequent issue of the ISP recording the first NIC mac address
    and using it to verify you as their customer. When you add a router after the fact,
    the ISP sees the router is not your system and we need to play tricks (offically) to make
    the router report itself as your system's nic.

    This is the masquerade option in the router settings.

    use the Physical Address reported from ipconfig /all and place that in the
    masquerade value and enable it. Save the settings and the router should restart.

    wait 30 seconds and rerun the ipconfig /all

    you should have all values present.
  17. bhbf

    bhbf TS Rookie Topic Starter

    How do I access the router settings?
  18. jobeard

    jobeard TS Ambassador Posts: 8,945   +584

    use your browse and enter a url with only the router IP address
  19. bhbf

    bhbf TS Rookie Topic Starter

    I've tried that and all I get is a "The address is not valid" page.

    But the system is recognizing the router and when I ping the address, I get a 0% loss.
  20. jobeard

    jobeard TS Ambassador Posts: 8,945   +584

    have you ever connected modem=>system w/o the router? did that work?

    Please report the ISP name, make/model of your modem and the router.

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