RT-AC66U + Shibby 120 problem

Discussion in 'Tomato Firmware' started by Connor McCaffrey, Jul 5, 2014.

  1. Connor McCaffrey

    Connor McCaffrey Networkin' Nut Member

    ok, so yesterday i wire 75 foot cable from RT-AC66U to DIR-655. then it will not work, link isnt happening, so i take the same cord, plug into modem instead of RT-AC66U, link works.


    change cable to RT-AC66U

    link works. shows up at 10mbps. but doesnt work, cant ping the router, then using same 2 cables, i went RT-AC66U ---> Swtich ---> DIR-655 and it worked.

    the RT-AC66U created the problem. the switch solved it. i dont wanna have to use a pointless switch!

    Last edited: Jul 5, 2014
  2. dmaster-mdg

    dmaster-mdg Reformed Router Member

    Sounds like your 75 foot patch cable is no good. Did you test your cables with a tester? Pretty sure you will need all 8 pins for 1 gig. If you are missing an "important" pin, could explain the 10 meg link.
  3. Connor McCaffrey

    Connor McCaffrey Networkin' Nut Member

    no its working for 1gbps link on everything else. ITS THE RT-AC66U / TOMATO CREATING THE ISSUE 99.999999%

    either its related to the switches on the RT-AC66U / DIR-655 not working well together or its related to the fact that the RT-AC66U in some way isnt putting out enough power into the cable

    the 10mbps link was only with another cable the cable im having problems with show NO LINK, it NEVER showed 10mbps. that was with another perfectly good cable into the RT-AC66U which proved the problem is in it again!

    2 perfectly good working cables going from RT-AC66U to DIR-655 ARE NOT WORKING WITH THESE DEVICES IN COMBINATION, then i switch cables to other devices, AND THEY BOTH HOLD GIGABIT LINKS AND DROP 0 PACKETS PERFECTLY FINE!

    when i use 75 foot cable between my laptop and RT-AC66U it works @1gbps.

    when i use 75 foot cable between my laptop and DIR-655 it works @1gbps.

    when i use 75 foot cable between RT-AC66U and DIR-655. no link

    when i use 30 foot cable between RT-AC66U and DIR-655. 10mbps

    when i use same 30 foot cable with my laptop and each router, it also HOLDS GIGABIT!

    THIS PROBLEM ALSO HAPPENED WITH THIS CABLE ON RT-AC66U and an ATM we had at my house. it would not hold a link from RT-AC66U to ATM, but back then i did think the cable was faulty when that happened, but now i know its not because when that happened i did not know why my cable just stopped working. i had took it out of use about a week before only to replace with a shorter cable as i did not need 75 feet and the clips on it are broken ( not causing the issue)

    edit: i should also add then when the second cable between dir-655 and rt-ac66u had 10mbps link. i couldnt even pink the dir-655.. because i was coming from the rt-ac66u
    Last edited: Jul 5, 2014
  4. PetervdM

    PetervdM Network Guru Member

    although they seem similar from the outside, there are in fact TWO distinct wirings on rj45 connections. those on "terminal" equipment use MDI, and those on "communication" equipment use MDIX. this has been done to be able to use a "straight" cable between equipment of each category. see: https://en.wikipedia.org/wiki/Medium_Dependent_Interface

    but if you connect two similar devices, fi routers, the connection is either MDI - MDI or MDIX - MDIX. in this case you need a cross cable, a straight cable might not work. might, as modern devices have auto polarity, as long as the port is configured for auto speed and auto duplex.
    it might be either router or router port is not configured for auto, or does not support auto polarity.
    you might try to reconfigure the ports for auto - both of them - or try a cross cable between them.

    Pin# color color
    1 white/green white/orange
    2 green orange
    3 white/orange white/green
    4 blue blue
    5 white/blue white/blue
    6 orange green
    7 white/brown white/brown
    8 brown brown

    568A 568B
  5. Connor McCaffrey

    Connor McCaffrey Networkin' Nut Member

    interesting, that sounds like a reasonable explanation, i will get a crossover cable and report back.
  6. Connor McCaffrey

    Connor McCaffrey Networkin' Nut Member

    @shibby20 is there any way this could be fixed so that the auto-negotiation works, its suppose to work.
  7. Marcel Tunks

    Marcel Tunks Networkin' Nut Member

    You should probably try the crossover cable before requesting a fix for something that may not be broken.
  8. Connor McCaffrey

    Connor McCaffrey Networkin' Nut Member

    if a crossover cable is required. its broken, there were features put in for the routers and switches to detect if a crossover is needed and apply it itself. it wasnt working properly, but i actually changed dns servers and added domain name and the gateway name on my DIR-655 and somehow it fixed it.......

    for some reason neither router wanted to auto-negotiate properly. only 1 router needed to co-operate in order for this issue to be solved.

    neither routers were co-operating

    i changed some settings on my d link and now magically it is.

    i also changed my WAN MAC on my DIR-655 but i AM NOT using wan and there is no bridge, my LAN mac is dif but if it matters i did change my WAN MAC because it was matching the mac of my PC
  9. Connor McCaffrey

    Connor McCaffrey Networkin' Nut Member

  10. PetervdM

    PetervdM Network Guru Member

    auto polarity only works if both devices:
    - support it,
    - are set for auto speed,
    - are set for auto duplex.

    the only way to be certain 2 MDI OR 2 MDIX devices can communicate with eachother is to use a cross cable.
  11. Connor McCaffrey

    Connor McCaffrey Networkin' Nut Member

    exactly, but why changing settings 100% unrelated to this changed it makes no sense, there is no option to change either of these settings on the wan ports for either router...........

    so for me to have made changes to anything that should have affected it is impossible, however some random changes i made fixed it......
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