Configuring a pair of asus rt-n12 routers. Pls. help

Discussion in 'Network Routers' started by Paulo da Silva, Apr 20, 2011.

  1. Hi!

    1st. of all sorry for the big post but I think this should be enough
    simple and clear for experts :)

    I have a netgear cable modem/router configured for network.
    Addresses are reserved for dhcp. is the gateway.

    I bougth 2 rt-n12: one to serve as a router (AP?) and the other as a

    I could not understand what is the difference between AP and router. So,
    I configured the 1st router as AP because there are too much fields to
    fill if I chose the router mode. I also set up the trivial wpa-2 AES
    wireless. Changed the entry address (browser access) from to - This one was unused.

    Everything went fine so far. All PCs see and work with this new
    roouter/AP. The problem came withe the second router set as repeater:

    There, it is supposed to choose a SSID from a list, insert its pass
    phrase (wpa-2 AES) and the router should be repeating it. There is also
    the possibility of choosing a LAN ip address (defaults to -
    this is also the entry addresse for the browser access - or choose DHCP.
    If I change the address, I can also specify a gateway - Whenever I
    choosed this, I used here. I cannot understand the role of
    this except as the address for the browser.

    Having said this let's see what happens:

    When I choose my SSID from the presented list *imediatelly after the
    router-repeater being reset*, it "loops" a big while saying it is
    connecting. Then it stops with the message "RT-N12 failed to
    automatically obtaining a new IP address from DHCP server. Please try
    again.". After this, choosing any SSID or the same again, I got
    imediatelly "Connection failed. The network you are trying to connect to
    may not exist. Please select another network to connect to."
    After this I need to reset to factory defaults to change this behaviour!

    I already played with the LAN IP thing changing its address. No success.

    Thanks for any comments/help.
    Paulo da Silva, Apr 20, 2011
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  2. Paulo da Silva

    Char Jackson Guest

    Model number would be nice.
    What problems were you trying to solve?
    Start here:
    Wireless Router: <>
    Heh, the usual approach is to use the mode that meets your needs, not
    the mode that's easier to configure. :) See above, what problems are
    you trying to solve? That will dictate how the equipment should be
    So far, so good.
    Do you really need a repeater? Wireless throughput will be cut in
    half, or less. is already being used by your Netgear modem/router, so
    you'll either want to use DHCP here or manually configure an IP
    address that's not already being used and does not fall within the
    DHCP scope. should be fine, with a Netmask of and a Gateway of
    Char Jackson, Apr 21, 2011
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  3. Em 21-04-2011 03:15, Char Jackson escreveu:
    This is a customized model for my ISP.
    Increasing the distance and quality.
    After playing with configurations I could see the difference.
    After understanding these concepts I still prefer, at least by now, the
    AP. To have a permenent configuration as router I need to change lots of
    things including all PCs firewalls and hosts permissions and names. I am
    using local fix IP addresses.
    I did an ad hoc configuration using only one PC and got all the same
    symptoms! So the problem is not here.

    I only have cable on one side of the house and the signal does not reach
    the other end using the netgear. With rt-n12, it seems better but I need
    more tests. It depends on how many people is using wireless around on
    the same channel and perhaps on the weather.
    So, a repeater seems a good solution.
    I tried that - fix and dhcp. No luck.

    I am almost sure that the second message
    "Connection failed. The network you are trying to connect to
    may not exist. Please select another network to connect to."
    is a bug. I need to restore to factory defaults to get rid of this
    message. May be there is another way but I could not find it.

    But what is the meaning of
    "RT-N12 failed to automatically obtaining a new IP address from DHCP
    server. Please try again." ?

    It is possible to obtain a dhcp address both from the netgear and the
    RT-N12 (when configured as router). I checked it using eth0 and wlan0

    Paulo da Silva, Apr 21, 2011
  4. Paulo da Silva

    Char Jackson Guest

    First, I don't understand why you bought two units, and second, is
    there a reason why you're not using powerline networking rather than
    trying to get a repeater to work? If powerline is an option there,
    it'll almost certainly be much faster and way more reliable,
    especially the newer stuff.

    Not to mention that a second router piggybacked onto the first router
    will mean two separate subnets and all of the fun that goes with that.

    What problem? What symptoms? Ad hoc is PC to PC, so how do you do ad
    hoc with a single PC?

    I think you'll find that a repeater is almost always the worst choice.
    Only choose it if everything else has been considered and rejected.

    You might have to move closer to your Netgear router, depending on
    what you mean by 'no luck'.

    When in doubt about your settings, restoring defaults is usually a
    good option. Not sure why you think the message you're getting is a
    bug. It sounds valid to me. Try moving closer to your router and make
    sure it's really your router that you're trying to connect to. If you
    haven't changed the SSID away from its default, you probably should.

    Pretty self-explanatory. The unit wasn't able to communicate with the
    DHCP server in your Netgear router. Since that's the case, static
    assignment of IP, netmask, and gateway will also fail since either way
    it needs to be able to communicate with the Netgear.
    Move the Asus closer to the Netgear router and make sure you're really
    trying to connect to your own Netgear router rather than a neighbor's.

    Hopefully you'll only enable one DHCP server per subnet or things can
    get wacky in a hurry. It's probably best to leave DHCP enabled in the
    Netgear and disable it in the Asus units. Then again, you said that
    everything has static IP assignments so perhaps you don't need DHCP at

    If it were me, I would try a pair of powerline network adapters. The
    Netgear router would be cabled to one of the adapters and the second
    adapter at the far end of the house would be cabled to a single Access
    Char Jackson, Apr 21, 2011
  5. Em 21-04-2011 10:52, Char Jackson escreveu:
    There are several reasons I don't want to mention here.
    I didn't know they already exist :-(
    I searched for wireless solutions and power lines are not wireless.
    Thank you very much to make me aware of them. Anyway I already bought
    the routers.

    BTW, do these powerline adapters work when plugged to different AC
    phases? Any need for phase bridges? I also saw some examples needing
    windows. I use linux here.
    Sorry. I used the "ad hoc" term in common language sense, i.e. "for the
    strict purpose". So what I did was to setup a temporary configuration
    with two subnets using a PC and a RT-N12 configured as a router to make
    some experiments.

    All tests were made less from 2m from the netgear/RT-N12 pair.
    As I said I am less than 2m from the router.
    The signal the "repeater" shows is at its maximum level.
    Here is what happens:

    1. I reset the router.
    2. Set it as a repeater (there is a switch for that).
    3. Connect my browser.
    4. Choose some IP+gateway or try DHCP. I played with these things a lot.
    5. Then I click on a button to choose the SSID to repeat.
    6. A list of SSIDs shows up. My routers SSID has the max. signal. I
    choose it.
    7. I was asked for the routers pass phrase. After inserting it, I got
    two behaviours:
    a) If coming from a repeater reset, it "loops" a big while saying it is
    connecting. Then it stops with the message "RT-N12 failed to
    automatically obtaining a new IP address from DHCP server. Please try
    b) After a), every time I insert the pass phrase (point 7) I imediatelly
    get the message
    "Connection failed. The network you are trying to connect to
    may not exist. Please select another network to connect to."

    That's why I thing this is a bug.
    Paulo da Silva, Apr 21, 2011
  6. Paulo da Silva

    Char Jackson Guest

    I'm successfully using some Netgear powerline adapters here. I can't
    answer your question about different phases, but I can confirm that
    they came with a Windows utility you can use to set or reset a
    security code, among other things. I didn't do any of that; I simply
    plugged them in and began using them.

    Hmm, using a repeater less than 2m from its source AP isn't going to
    work well and may not even work at all. There's nothing ideal about
    using a repeater, but ideally the repeater will be physically located
    where it has good communication with the source AP, your Netgear in
    this case, and where the target PC's can communicate with the repeater
    but they can't hear the source AP. If the target PCs can see both the
    source AP and the repeater, things get messy from an RF perspective.
    Best case, throughput will be in the weeds, but worst case there will
    be no throughput at all.

    Your PC is connected to the repeater with an Ethernet cable, I hope.
    Whenever possible, always configure network elements with a wired

    Try it after disabling the wireless security on your Netgear. If it
    works, you know it's a security issue.

    If at all possible, you should consider running an Ethernet cable
    between your Netgear router and your Asus unit so that the Asus can be
    configured as an Access Point rather than a repeater. Setup is easier,
    and day to day performance will be much better (faster, more reliable,
    etc.). If it's not practical to run Ethernet cable, it may not be too
    late to try powerline networking to get the AP where you need it.
    There's even such a thing as Ethernet over coax, in case that's a
    better fit for you. Basically, almost anything is better than a

    By the way, this is kind of turning into a wireless discussion so you
    might consider posting to alt.internet.wireless. There are some great
    people over there who know wireless inside and out.
    Char Jackson, Apr 21, 2011
  7. Em 21-04-2011 21:15, Char Jackson escreveu:
    And is there any encryption by default?
    It is not to be used there! It's just for the first connection.
    There is a utility that makes the 1st connection just to configure it.
    Then it will be moved to another place in the middle of the house.
    It's in the manual ...
    Thanks for the tip.

    I think the router is broken. I contacted the co that sold me these
    routers and they confirmed this could be a hw problem. I'll send it to
    them so they can test it themselves.

    Thanks a lot for your answers.
    Paulo da Silva, Apr 22, 2011
  8. Paulo da Silva

    Char Jackson Guest

    I'm not sure, but I don't think so. It's not needed here at my place,
    but to enable or change the encryption you simply push a button on one
    adapter, then within 2 minutes you go push the same button on the
    second adapter. The two adapters find each other and negotiate a new
    encryption key. No need for any PC (Linux, Windows, whatever).

    I always frown at the use of those automated utilities, greatly
    preferring to do the setup manually so I know what's going on.

    Sure thing. Good luck with everything!
    Char Jackson, Apr 22, 2011
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