Internet disconnects and won't reconnect until restart

By gildedarmour
Feb 21, 2014
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  1. I've been having this problem for only the last week or so where my internet will stop working until I restart my computer, even though it says I am connected and internet is available.

    The problem is not with my modem or my router. The internet works fine on every other computer.
    I've run multiple antivirus scans on multiple programs. Clean.
    Drivers are up to date.

    Sometimes it disconnects after five minutes, sometimes forty, sometimes hours.
    I'm at a loss. Any ideas?
  2. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,451   +135

    What is this computers make and model? How does it connect to the Internet?
  3. gildedarmour

    gildedarmour Newcomer, in training Topic Starter

    I dont know the model. All it says is "To be filled by O.E.M"
    This is a computer I had built for me.
    It connects with ethernet cable.
  4. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,451   +135

    "I've run multiple antivirus scans on multiple programs. Clean"... How many "antivirus" programs do you have installed. What are these programs... the names?
  5. jobeard

    jobeard TS Ambassador Posts: 13,026   +221

    When it disconnects get us some information:

    get a command prompt (start->search, enter CMD and press return)
    then enter
    ipconfig /all >myTCP.txt
    open that file, copy all the content and paste it back into your follow-up reply.

    I suspect you're loosing the DHCP server
  6. gildedarmour

    gildedarmour Newcomer, in training Topic Starter

    Avast and microsoft security essentials. and aight I'll try that next time it goes down. I also just rebuilt my computer from scratch and that didn't solve it. :(
  7. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,451   +135

    "Avast and Microsoft security essentials"... Pick one only and completely un-install the other! Then do what jobeard said
  8. gildedarmour

    gildedarmour Newcomer, in training Topic Starter

    I only had one installed at a time.

  9. jobeard

    jobeard TS Ambassador Posts: 13,026   +221

    Code:
    Default Gateway . . . . . . . . . : 192.168.0.1
    DHCP Server . . . . . . . . . . . : 192.168.0.1
    those are quite normal - - pointing to your router.

    Have you power-cycled that router {recently or ever}? Do so. wait at least 30 seconds before restarting it.

    When the symptom reoccurs, get the command prompt again and enter
    IPCONFIG
    you should get back
    Code:
    IPv4 Address. . . . . . . . . . . : 192.168.0.3(Preferred)
    Subnet Mask . . . . . . . . . . . : 255.255.255.0
    Lease Obtained. . . . . . . . . . : Monday, February 24, 2014 6:20:37 PM
    Lease Expires . . . . . . . . . . : Monday, February 24, 2014 7:50:38 PM
    Default Gateway . . . . . . . . . : 192.168.0.1
    THEN FOLLOW with
    IPCONFIG /RELEASE
    IPCONFIG /RENEW
    and lastly
    IPCONFIG /ALL

    you should have the default gateway dhcp & dns addresses again.

    If not, then there's a problem in the router
  10. gildedarmour

    gildedarmour Newcomer, in training Topic Starter

    And assuming it works, that should fix it permanently? Like, it won't keep losing internet and I'd have to type that stuff in?
  11. jobeard

    jobeard TS Ambassador Posts: 13,026   +221

    "should fix it permanently?" Hmm. Even when you have a hair permanent, you still go back again - -
    The Rock of Gibraltar might be, but I would never call anything with computers permanent :sigh:
    Last edited: Feb 25, 2014
    learninmypc likes this.
  12. gildedarmour

    gildedarmour Newcomer, in training Topic Starter

    Ok so, when I did that I got up to ipconfig /renew but when I entered that command, a line popped up and said "Windows IP Configuration" and I couldnt enter anything else.
  13. gildedarmour

    gildedarmour Newcomer, in training Topic Starter

    Oops, and then a few minutes after that it says "An error occured while renewing interface Local Area Connection : unable to contact your dhcp server. Request has timed out."
     
  14. gildedarmour

    gildedarmour Newcomer, in training Topic Starter

    Fpfpffpffft ok I reset my winsock and then tried it again when I lost the internet and it worked this time. everything is the same as it was before soooo, does that mean the problem isnt fixed?
  15. gildedarmour

    gildedarmour Newcomer, in training Topic Starter

    Yeah ok I lost connection again 2 minutes after I did that. so its my router, then?
  16. Philip Booth

    Philip Booth Newcomer, in training

    Perhaps you need to extend the main memory, I guess that your computer run number of heavy software together with internet.
  17. gildedarmour

    gildedarmour Newcomer, in training Topic Starter

    I was one tab of youtube and google when it shut down that time. Why would it be the memory? I've never had a problem before this last week and a half.
  18. jobeard

    jobeard TS Ambassador Posts: 13,026   +221

    NO! it's not memory.

    You have two different issues
    1. frequent disconnects
    2. failure to honor a release/new cycle
    Let's talk about your ISP connection - -
    WHO is it and what type {Dsl, Cable, Satellite} ?

    DSL has special considerations which requires a filter on every device connected to the phone line OTHER than the modem. This is a direct contributor to the disconnect problem (*IF* you're using dsl)

    You ought to get the make/model number of the router and look for a firmware update (regardless of {Dsl, Cable, Satellite} as you ought to be able to renew).

    Here's a test you can run to determine if your router needs to reassemble packets:

    get the command line and enter:
    ping -f -l 1500 google.com​
    the character between the -F and google is an ELL in lower case.

    My results are:
    C:\Users\Jeff>ping -f -l 1500 google.com
    Pinging google.com [74.125.224.168] with 1500 bytes of data:
    Packet needs to be fragmented but DF set.​

    Now repeat that test by reducing the 1500 by -8 until it replies
    C:\Users\Jeff>ping -f -l 1440 google.com
    Pinging google.com [74.125.239.0] with 1440 bytes of data:
    Reply from 74.125.239.0: bytes=1440 time=18ms TTL=53​

    My test of the value just above that produced:
    C:\Users\Jeff>ping -f -l 1448 google.com
    Pinging google.com [74.125.239.0] with 1448 bytes of data:
    Request timed out.​

    When packets get fragmented, the router needs to do extra work and not only is that a performance hit, but also a vector for network virus' - - so help the poor thing along by setting the MTU in the router itself.

    Set the MTU to the highest value that replies with times and does not timeout.


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