Ethernet Works, Wifi Doesn't

By slid180
Mar 1, 2016
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  1. Hi everyone,

    I've been having problems with my wifi for a while now. When I plug my ethernet cable into my laptop, my internet works fine and speeds are great. However when I try to connect to wifi on my laptop or my smart tv the internet loses signal every few minutes or so. If I wait a minute or two the signal comes back and will work for a little while longer.

    I'm not sure what the problem is. When using wifi, the laptop and smart tv work sporadically (however netflix will usually stop mid tv show and say the device isn't connected to the internet). When I'm on the computer I'll show full wifi strength but I get a little yellow flag that says no internet connection. Then after a few minutes, the flag goes away and I can browse for another couple minutes.

    Any ideas where I should start looking?
  2. jobeard

    jobeard TS Ambassador Posts: 9,147   +597

    Make/Model of your wifi router?
  3. slid180

    slid180 TS Rookie Topic Starter

    Cisco RV110W Wireless-N VPN Firewall.

    It's pretty much a brand new router.
  4. jobeard

    jobeard TS Ambassador Posts: 9,147   +597

    Try this (in the order shown)

    get the latest firmware for your router

    for the PC, use only a {wired OR Wifi} connection, but not both
    by disabling the one to be ignored

    to make the router connections more reliable
    change the MTU to 1492
    which will avoid buffer overflows.
  5. jobeard

    jobeard TS Ambassador Posts: 9,147   +597

    And YES, even out of the box routers sometimes have updates - - at least LOOK :)
  6. slid180

    slid180 TS Rookie Topic Starter

    You called it jobeard. My new router had not so new firmware. I've updated the firmware.

    An MTU of 1492 means I get fragmented packets so I've left it at 1500.
  7. jobeard

    jobeard TS Ambassador Posts: 9,147   +597

    NOPE; exactly the opposite. An MTU < 1500 ensures that fragmentation does not occur and that is frequently a reason for disconnects.
    Trust me, I've even set my own to 1492.
  8. jobeard

    jobeard TS Ambassador Posts: 9,147   +597

    What's your current status ??
  9. slid180

    slid180 TS Rookie Topic Starter

    Definitely a big improvement just by following your recommendations jobeard. Been testing things out the past few days and have not lost internet connection yet!

    Thank you!
  10. jobeard

    jobeard TS Ambassador Posts: 9,147   +597

    Welcome. It's definitely counter-intuitive. The mechanics of TCP uses MTU discovery to find the smallest mtu in the path. Then the sender delivers packets of that size which never need to be reassembled when received.

    Otherwise, the receiving end (your pc NIC or WiFi) has to
    • get more than one buffer
    • move packet data inbound to the buffer
    • add the missing pieces as they arrive to that buffer
    • and finally show what was intended
    Taking time, memory and sometimes suffering buffer overflow and crashing the connection.

    Funny but LESS is MORE :)

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