Please Help with (Failing?) RT-N16

Discussion in 'Tomato Firmware' started by dthatcher, Feb 28, 2012.

  1. dthatcher

    dthatcher Networkin' Nut Member

    I purchased my RT-N16 in Feb 2011. I immediately loaded TomatoUSB build 54 and it ran fine until the end of January 2012. Now, a couple of times a week, the wireless will fail to connect. Ethernet works fine, I can SSH in, everything else is gold, but my computers (wireless clients), although they see my wireless network, refuse to connect. Resolving the issue requires a reboot of the router.
    What I have tried:
    1. Updated to Toastman (just a week or so ago)
    2. Set Wireless mode to G only
    3. Underclock router via Tomato GUI to 300Mhz
    I am still having the problem. Is it time for a new router? Or do you have any other suggestions?
  2. Monk E. Boy

    Monk E. Boy Network Guru Member

    I would try a thorough NVRAM wipe, AKA "Erase all data in NVRAM memory (thorough)" under Administration -> Configuration, then set everything up from scratch (don't restore settings from a backup .cfg file).
  3. dthatcher

    dthatcher Networkin' Nut Member

    Thanks Monk.... I cleared NVRAM redid the settings by hand when I upgraded to Toastman (cleared before and after, then did settings).
  4. kthaddock

    kthaddock Network Guru Member

    Use toastman 7496 or 0496
    Try "Auto"
    Don't under clock no need to do that.

    Don't use hidden ssid "brodcast"to test. 40Mhz channel witdh, choose it self.
    wpa2 personal+aes and use ascii Shared Key.
    If you don't get that to work look at your card drivers. Some intels card have major problem.

    last solution, post pic on all your wifi settings !

  5. dthatcher

    dthatcher Networkin' Nut Member

    I've reverted back to Auto. I will reset to stock speed and switch from WPA2 Personal TKIP+AES to AES only, and report back. I would prefer not to go to 40Mhz as a "good neighbor" measure, unless it really might solve this problem?
  6. Planiwa

    Planiwa Network Guru Member

    I may have a similar problem with a 3 month old N16 -- have reverted back to the old WRT with 9dB antennae.

    Time to do some wifi tests on the N16. . . .
  7. Toastman

    Toastman Super Moderator Staff Member Member

    You might experiment a little - have seen several instances of this happening where the PC's wireless card has powered into some sort of sleep mode, and restarting the router apparently made it wake up. Turn off any power saving or suspicious looking settings in the wireless setup. Also, on the router, turn off power saving (APSD) under Advanced/Wireless/WMM.

    I rather doubt there's anything wrong with your router.
  8. dthatcher

    dthatcher Networkin' Nut Member

    I have done all of the above recommendations (with the exception of the specific build recommendation) and still have the problem. My desktop is running an RT61-based adapter, while the laptop has an Intel Wifi Link 1000 adapter. Although I was having this problem before I brought the laptop into the mix. Below are screenshots of my configuration:
  9. kthaddock

    kthaddock Network Guru Member

    Your setting looks fine, for testing, set width to 40Mhz.
    So I think your problem is wireless card and these setings. Look for power savings and green internet settings and turn them off.
    And see if you can find latest driver to your wireless card and update them. You can download InSSIDer an look for other nets who can interrupt.

    RT-61 adapter is ralink G-adapter
    Intel Wifi Link 1000 adapter

  10. bluenote

    bluenote Addicted to LI Member

    I'm having what sounds like the same problem, but may not be. I know it's the router because i can turn on wifi on my phone or any other client and fail to connect until the router is rebooted. unfortunately i don't have enough data yet to help much. happens about every day or two it seems. so by all means investigate your clients, but keep this in mind. i'll check back when i've observed my problem some more.
  11. dthatcher

    dthatcher Networkin' Nut Member

    I've taken to doing some experimenting. I have read that too much interference can prevent the router from acknowledging a client connection. A site survey reveals some truly depressing things for me. For one, somebody is running 20 and 40 Mhz channel width networks on Ch9, there's someone on Ch2, someone on Ch3, 5 APs on Ch11, 2 APs on Ch6, and 3 APs on Ch1. So I don't dare run Ch11, Ch6 puts me in the interference zone of the rude people on Ch9, leaving me Chs.4&5 except I don't want to be a bad neighbor, which leaves me with Ch1. I've had the Ch. selection on Auto, so I think what's happening is that it gets SO bad that I have to reboot the router to force it to change to a different channel to overcome whatever interference is preventing connections. Although, since it only happens a few times a week, I doubt it is purely the congestion that is to blame. For that reason I have enabled Interference Mitigation with a setting of Non-WLAN. I've left the channel selection to Auto and it chose Ch.1 on the last reboot. So we will see what becomes of this setup!
  12. kthaddock

    kthaddock Network Guru Member

    Okey, I missed you Auto setting on channel. Choose channel 1-6-11 upper or lower.
    Use "Wlan Auto with noise reduction" that can help to reduce noise environment.
    Regarding to use 40Mhz you must use that to reach 300 Mbps.

  13. fubdap

    fubdap LI Guru Member

    I wish there is a way you can communicate to neighbors to make them use the main channels (1,6,11). The problem is they use fancy names for their ssid, so you don't know who is who.
  14. bluenote

    bluenote Addicted to LI Member

    EDIT: I spoke too soon on all 3 devices! This changes what I've observed quite a lot.

    Hey dthatcher

    I just caught this happening, and had a few minutes to do some troubleshooting. I noticed it on 1 client and then reproduced it on two others.
    Two devices would not authenticate, and one would connect but not have any connectivity.
    As soon as I clicked 'do a wireless survey' on the router , the client without connectivity began to work. The two other clients that could not authenticate, would still not authenticate though.

    I don't know that we've got the same root cause but I'd be very curious if you catch this happening in the act and this temporarily solves it for you (partially?)
    better than a router reboot.

    And anyone else who might want to lend some knowledge on what 'wireless survey' does that would fix a problem? I dont imagine its a service restart, its too fast.

    EDIT: Resetting the wireless service did fix the problem for my two other clients, but thats not really surprising is it?
    EDIT: Country set to Canada.
  15. Planiwa

    Planiwa Network Guru Member

    Interesting. Perhaps this could be done automatically, using wl, if all ealse fails . . .

    Meanwhile, my new wlprobe tool (on Mac OS X) is making astonishing discoveries. . . . will report shortly.

    Q: what is your country setting?
  16. Planiwa

    Planiwa Network Guru Member

    We may be converging on the root cause . . .

    I did:

    1. set country to Canada
    2. set last 5 parameters to defaults
    3. save

    Now wifi won't connect! Ether won't connect either. No ping.

    Tomato v1.28.7821 MIPSR1-Toastman-ND K26 Mini

    (this was done with nocommit, which setting was not in flashed nvram)

    It seems to me that there is a peculiar relationship between

    wl command

    wl & wl0 in nvram image

    virtual (ephemeral RAM) NVRAM

    flashed NVRAM

    and possibly the NoCommit setting
  17. dthatcher

    dthatcher Networkin' Nut Member

    An update: Maybe I am speaking too soon but I think I have resolved my problem. I am pretty sure my issues were rooted in interference. The Auto setting in Tomato just wasn't aggressive enough to avoid it. I think it takes a while before Tomato stops and says, oh yeah, there's lots of interference, let's try a different channel. Rebooting the router, of course, forces a channel reselect. I presume that initiating a site survey also forces a channel reselect. Since changing Auto to Ch.1, I haven't seen a problem. Of course, if your situation is really bad, setting the optimal channel may not be enough, and you may need to enable Interference Mitigation, which I did as well.
    One very interesting thing that I noted: running the site survey within Tomato showed a lot more signals than running inSSIDer on either of my clients. This is how I discovered the 40Mhz network on Ch.9, and ultimately how I decided on Ch.1.
    Looking back, I think what precipitated my problem was moving the router (which is mounted on the wall) closer to the window. I did this because I had to move my printer against the window to make room for cabinets and the USB cable wouldn't reach the old location. I figured moving the router over a foot was cheaper than spending $20 on a really long USB cable at Target. I live in a small apartment, and the living room where the router and printer are is very cramped, so I have few options, since the cable modem is there. However, this obviously exposed it to more interference.
  18. Planiwa

    Planiwa Network Guru Member

    The IM GUI options I see:
    wlan manual
    wlan auto

    wl has:

    Get/Set interference mitigation mode. Choices are:
    0 = none
    1 = non wlan
    2 = wlan manual
    3 = wlan automatic
    4 = wlan automatic with noise reduction

    Does 7476 offer #4 in the GUI?

    Or should I set it in wl?
    # wl interference 4
    # wl chanim_mode 2
    # wl interference
    Auto Wireless LAN Interference mitigation is enabled and not active, and noise reduction is enabled. (mode 4)
    # wl chanim_mode
    CHANIM mode: detect + act.
    # nvram find mitigation
    Maybe I also need to do

    # nvram set "wl_mitigation=1"

    and or

    # nvram set "wl0_mitigation=1"

    (What are wl and wl0 in nvram? Why are there 2 of them?)

    [Tomato v1.28.7494 MIPSR2-Toastman-VLAN-RT K26 USB VPN-NOCAT]
  19. Planiwa

    Planiwa Network Guru Member

    It just occurret to me that "Wireless Survey" is an easy way (with minimal irrational side effects) to try to nudge the wifi device if it appears to have doze off. Of course this assumes that you (still) have access to the router, either by ether, by WAN, of by a functioning wifi connection.
  20. bluenote

    bluenote Addicted to LI Member

    I don't like non methodical or non-repeated confirmations, but for now i'll say, i ENABLED wmm and my issues with wifi seems to have disappeared. since Thursday afternoon.
  21. dthatcher

    dthatcher Networkin' Nut Member

    An update:
    While a static Ch.1 setting resolved my problems, it wasn't an ideal channel to use in the evenings (for whatever reason, I was having severe slowdowns). I moved back to the "Auto" setting but left Non-WLAN Interference Mitigation on. So far, so good. Will update here again later.
  22. dthatcher

    dthatcher Networkin' Nut Member

    Another update:
    Still having problems on Auto. And yes, initating a wireless survey solved the problem, although the channel didn't change. I am going to try a different channel setting.
  23. bluenote

    bluenote Addicted to LI Member

    After having enabled WMM and no other changes it's now been nearly a week without any wireless screwups. Whereas I was having to reboot every 24 - 36 hours before.

    These are my current defaults:
    Interference mitigation: none
    WMM: Enable
    No Ack: Disable
    APSD: Enable
    Wireless Multicast forwarding: Disable

    Any of these different for you dt?
  24. dthatcher

    dthatcher Networkin' Nut Member

    I have Interference mitigation at WLAN-Auto (I have also tried Non-WLAN)
    APSD is off at Toastman's suggestion, but I will experiment with it!
  25. dthatcher

    dthatcher Networkin' Nut Member

    Setting APSD to on did not resolve the problem. I am beginning to think only manual channel selection will solve my problem here. I am going to try Ch.11.
  26. bluenote

    bluenote Addicted to LI Member

    Why not duplicate those last settings I posted dt? incl interference mitigation off. I'm still wireless problem free.
  27. Planiwa

    Planiwa Network Guru Member

    Did you ever try:

    4 = wlan automatic with noise reduction:

    wl interference 4

    This does not appear in the GUI, but kthaddock suggested it, IIRC.

    Also, it seems that if MME is off, it shouldn't matter what APSD and No-ACK are.

    (And in the GUI those two suboptions should not show if MME is disabled).
  28. bluenote

    bluenote Addicted to LI Member

    Well, it turns out after adding a lot of extra time my problem is not actually solved, just severely mitigated.
    I still occasionally get wireless becoming unresponsive on all devices, that magically clears up as soon as I do a wireless survey,
    however from the frequency of about every 24 hours it is now about once every 7 - 10 days.
    I'd sure like to get this solved 100% though, because there's other people than me that use the wifi and having it be down until
    I notice sortof sucks.
  29. dthatcher

    dthatcher Networkin' Nut Member

    The only definite solution I have found is setting a channel, instead of using Auto. My theory is that the wifi interference gets to a level that stumps the router when it tries to change to a better channel.
  30. bluenote

    bluenote Addicted to LI Member

    So you ended up solving your problem this way? How long has it been problem free? Longer than 7 - 10 days?
    Did you happen to discover any other telltale signs ? It's so odd that a wireless survey resets whatever the problem is.
  31. kthaddock

    kthaddock Network Guru Member

    Well it's in my build.................... :eek:

    Attached Files:

  32. dthatcher

    dthatcher Networkin' Nut Member

    I gone over two weeks with no problem. I can only assume that the wireless survey combined with the Auto setting forces a channel reselect, even if the resulting channel remains the same.
    The solution isn't ideal as the channel I have picked (11) is still not the best, but it's solid with acceptable performance. I chalk it up to where I have the router + the wifi around me.
  33. Planiwa

    Planiwa Network Guru Member

    That's good to know! I'm running ...
    Tomato v1.28.7494 MIPSR2-Toastman-VLAN-RT K26 USB VPN-NOCAT

    I have made some outrageous discoveries about wl.
    Will be posting more in a few minutes in the "wireless -- wl" thread.

    @thatcher -- you can automatically run "wl scan" once a day, if you think that helps.

    I've actually been running it every 5 minutes for about a week.

    I've also started deplaying FAILSAFE, which resets most things if there has been no wirelss activity for 2 hours. (except during the core nght hours.)

    It has not yet had to act to fix a real problem.
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