Posted: Sat May 18, 2013 14:25 Post subject: Problems with wireless access point and DHCP with some OS
Hi,
DD-WRT n00b here, but I did RTFM, installed the right software on my TP-Link TL-WA730RE v1 (as found here) and got it up and running just fine using the wiki page for configuring a wireless AP (found here).
It worked great! I was sitting in my garden with my Macbook Pro on my knee, all smug my range extender was finally useful instead of randomly freaking out like it used to on the old firmware...
Then my wife spoiled the party. Whenever her Windows 7 Lenovo ThinkPad tries to connect to the range extender, it can't connect to the Internet. Nor can my Android 2 phone (a Samsung Galaxy Y - yes, I know, I'm a cheapskate!)
So, Mac OSX + MBP, works great... Linux (Ubuntu LTS 10.04) also works great, both connect to the range extender and get an IP address via DHCP from the main router (another TP-Link, this time a TD-W8961ND v1 - no DD-WRT support, sadly).
Edit: I had said Android was OK with a static IP, but it occurred to me I hadn't truly tested that - just assumed it would be, and why not? But turns out, Android with a static IP connects but cannot access the Internet. And Windows 7 with a static IP resolutely refuses to connect to the AP at all! Updated notes, regarding Android, below.
Weird!!
Thoughts?
For reference, here are a load of testing steps I did using the Linux netbook and the Android phone:
Code:
=================================
set AP to 'DHCP forwarder' with DHCP server as main router
rebooted AP
=================================
USING LINUX:
DHCP SETTINGS -> FORWARDER, COMPUTER IP -> AUTO (WORKS), IP: 192.168.0.23
=================================
released IP address on Linux machine
disabled networking on client devices
set AP to 'DHCP disabled'
rebooted AP
enabled networking on client devices
=================================
USING LINUX:
DHCP SETTINGS -> DISABLED, COMPUTER IP -> AUTO (CAN'T CONNECT)
USING ANDROID:
DNCP SETTINGS -> DISABLED, COMPUTER IP -> AUTO (CAN'T CONNECT, CANNOT OBTAIN IP)
USING LINUX:
DHCP SETTINGS -> DISABLED, COMPUTER IP -> MANUAL (WORKS)
USING ANDROID:
DNCP SETTINGS -> DISABLED, COMPUTER IP -> MANUAL (CONNECTS, BUT NO INTERNET ACCESS)
=================================
released IP address on Linux machine
disabled networking on client devices
set AP to 'DHCP enabled' with different range to main router (70-100)
rebooted AP
enabled networking on client devices
=================================
USING LINUX:
DHCP SETTINGS -> ENABLED, COMPUTER IP -> MANUAL (WORKS, but had to restart local networking a couple of times)
USING ANDROID:
DHCP SETTINGS -> DHCP SERVER, COMPUTER IP -> AUTO (CONNECTS, BUT NO INTERNET ACCESS), IP: 192.168.0.70
USING LINUX:
DHCP SETTINGS -> DHCP SERVER, COMPUTER IP -> AUTO (WORKS), IP: 192.168.0.23 (strange! renewed lease, got offered 192.168.0.23 again from main router)
=================================
released IP address on Linux machine
disabled networking on client devices
set AP back to 'DHCP forwarder'
rebooted AP
enabled networking on client devices
=================================
USING LINUX:
DHCP SETTINGS -> FORWARDER, COMPUTER IP -> AUTO (WORKS), IP: 192.168.0.24
USING ANDROID:
DHCP SETTINGS -> FORWARDER, COMPUTER IP -> AUTO (CAN'T CONNECT, CANNOT OBTAIN IP)
=================================
released IP address on Linux machine
disabled networking on client devices
set AP to 'DHCP disabled'
rebooted AP
enabled networking on client devices
=================================
This is the current state, Linux is happily using DHCP and getting assigned an IP, Android and Windows 7 are not.
Wow, OK, I'm going to have to revise this... to be honest, I'm really struggling to find any sort of consistent behaviour. As far as I can tell, the following is true:
1. When the DD-WRT powered range extender is on the network, it works for the Windows 7 machine and the Macbook Pro ... but neither can connect to the original TP-Link router. They can authenticate with the wireless, but they don't get an IP address. They connect to the network and the Internet fine via the range extender though.
2. For some reason the Android phone does *exactly* the reverse, it seems fine on the TP-Link main router but unable to access anything via the range extender.
3. When the DD-WRT range extender is switched off, the TP-Link router is fine, everyone can connect, all devices behave the same.
The tests I did with the Ubuntu machine seem to have been false positives. Here's what I just did now, which has completely thrown me back to square one again:
A. Linux machine was connected to range extender working fine. I turned off the networking on the client and went close to the main router, enabled networking again and it connected to the main router fine and had Internet access.
B. Went back downstairs (without disabling networking), disconnected and reconnected while standing close to the range extender - and it wouldn't connect.
C. Rebooted, wouldn't connect.
D. Rebooted range extender, wouldn't connect.
E. Changed from DHCP disabled to DHCP forwarder, rebooted range extender, wouldn't connect.
F. Switched BACK to disabled, assigned static IP, could browse to DD-WRT in browser, but couldn't get anywhere else on the network, no Internet, no browser access to main router. (Through all this Windows machine is connected to the range extender and fine.)
So I do not know WTF is going on any more. The Linux machine I was successfully testing with has gone crazy and now refuses completely to connect to the range extender, while the Mac and the Windows machine both *only* connect to the range extender. And the Android phone seems to be matching the Linux machine's new behaviour.
Too weird for me, I'm totally confused! For now, switched off range extender, main router works fine with the range extender off, but wtf is actually going on here?
Joined: 21 Dec 2011 Posts: 92 Location: São Paulo - Brazil
Posted: Sat May 18, 2013 20:12 Post subject:
Hmmm... long story made short, you are having problems with your Repeater, right?
I have a Repeater here also, 13+ devices connected to it, Windows, Linux, Androids, MacBooks, cellphones, tablets, they all connect and work just fine. I'm using different routers thou (TpLink WR2543 as main and Buffalo WHRG300N v2 as repeater), but I don't think right now that your hardware is the problem... and since you stated that all your devices work well without the extender, I think we should take a closer look in the way you set the repeater configs.
First things first: what DD-WRT build are you using in your repeater? Did you check the WIKI on Repeaters?
I think you're probably right, I suspect it is settings, but I have followed the instructions and the network doesn't behave consistently, which is really throwing me.
I haven't looked at the Repeater instructions because I'm not actually setting up a Repeater (picking up and re-transmitting a wi-fi signal) - I'm setting up an access point (physically wired to the router and transmitting its own wi-fi signal) and I have read the instructions for that. In fact, I followed them to the letter:
Edit: I should clarify, the device *is* supposed to be able to act as a range extender (repeater) *or* a wireless access point and I want to use it as an access point, *not* a repeater. The TP-Link firmware allowed for this too but was unreliable. Thinking about it, symptoms were kinda similar, so it could be some incompatibility or main router setting? If it's incompatibility, that would be really annoying, as I deliberately stuck with a single brand to try and avoid any issues like that!
Joined: 21 Dec 2011 Posts: 92 Location: São Paulo - Brazil
Posted: Sun May 19, 2013 14:36 Post subject:
Sorry about that, I failed to notice that you were using a wired link between them =)
I tried doing the same here, and it "seems" to work. I didn't do much testing with it (lots of people using them here), and tried with the "short lazy" options:
- Putting a cable in one of the LAN ports of the main router and connecting it to the WAN port of the secondary; main router sits at 192.168.1.1, DHCP server on.
- Letting the secondary receive an automatic IP from the primary (connection type - automatic config DHCP), and also leaving DHCP Server turned on on the secondary (with both DNSMasq and Authoritative DHCP off); Secondary was configured in a different subnet: 192.168.2.1
- Configured my wireless mode as AP, whatever channels and securities.
It worked. I know that this is not the optimal config, especially the two DHCP Serves, but it works. I can connect to both routers wired and wirelessly, I get my ips correctly and can surf the web. Even if the primary is down I still connect and receive an IP from the secondary, and can see the other devices connect to it (no internet with the primary down, off course) But like I said, I didn't test it much to found the bugs =D
Care to try that? If it works for you too we can try to improve it from this point! Remember to remove any scripts that you put on the secondary before trying, because they can also mess things in other configs rather than the ones they were designed for...
I could try a different subnet entirely, just to see if that works. Not ideal, but worth seeing if that functions OK. It's certainly an option. Thanks for the suggestion!
I'm still having problems - I gave up on the wired connection, I think the problem with that is I don't know enough about networking and making a network bridge to get this to work. PEBKAC!
I don't know how it works, but with client (bridged) mode assigned to the AP I've managed create another virtual AP, join the two routers and properly repeat the network.
But DHCP is flaky as hell. Sometimes it's fine for ages, sometimes I lose connectivity every thirty seconds or so. Something really weird happens, I can't even ping the main router, I can't get past the repeater but if I just renew my DHCP lease everything is fine again... for a few minutes, then it repeats.
I'll have a dig around the forum and see if I can find a similar issue.
I'm still having problems - I gave up on the wired connection, I think the problem with that is I don't know enough about networking and making a network bridge to get this to work. PEBKAC!
I don't know how it works, but with client (bridged) mode assigned to the AP I've managed create another virtual AP, join the two routers and properly repeat the network.
But DHCP is flaky as hell. Sometimes it's fine for ages, sometimes I lose connectivity every thirty seconds or so. Something really weird happens, I can't even ping the main router, I can't get past the repeater but if I just renew my DHCP lease everything is fine again... for a few minutes, then it repeats.
I'll have a dig around the forum and see if I can find a similar issue.
from what your describing its not a dhcp issue, dhcp just assigns you an address it has nothing to do with pings or the router replying. once you have an address dhcp leaves your device alone. you have router issues for sure, its just not dhcp. now if you had issues with getting an address from the dhcp server, then that's a dhcp issue.
