Posted: Fri Jun 17, 2011 6:06 Post subject: WNDR3700 weirdness, dies when connecting with laptop
I'm having a hard time debugging this issue, so any troubleshooting tips will help.
I have WNDR3700 v1 with dd-wrt version v24-sp2 (11/21/10).
Every time I connect with my laptop, Latitude E6400, the router dies and I have to power cycle it to get anything working again. By "dies" I mean the wan connection doesn't work, lan ports don't work and all wifi clients are dropped. LEDs still flash as if there was activity. If I am ssh'd into the router (from a different PC) it locks up and the session is unresponsive.
The router is usable for many other clients and only drops when I connect with this particular laptop, so I suspect it is a combination of my laptop and the router interacting.
The laptop runs Arch linux, 2.6.39 kernel and the wifi card is as follows:
0c:00.0 Network controller: Intel Corporation Ultimate N WiFi Link 5300
Subsystem: Intel Corporation Device 1121
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0, Cache Line Size: 64 bytes
Interrupt: pin A routed to IRQ 47
Region 0: Memory at f1ffe000 (64-bit, non-prefetchable) [size=8K]
Capabilities: <access denied>
Kernel driver in use: iwlagn
Kernel modules: iwlagn
I have set up a remote syslog to another machine, but no usable info is there. I suspect I need to restart syslogd with a different log level to be as verbose as possible.
I've tried updating firmware, but it fails, semi-bricked it twice and had to tftp restore back to this working version.
Any tips on debugging or how to troubleshoot are much appreciated. Thanks!
Router: TP-Link TL-WR1043ND
Firmware: v24 preSP2 [Beta] Build 14896
Wireless: Intel Corporation WiFi Link 5100 (iwlagn)
OS (Client): Arch Linux x86_64 (2.6.39-ARCH Kernel)
Even though no router should collapse because of a malfunctioning client, the issue seems to be related to a bug within the 39er-Kernel, affecting cards of the iwl3945, iwl4965 and iwl5000-series:
Most people only seem to have performance issues, but I guess it might be the same bug which causes DD-WRT driven routers to break down. According to the forum thread, it has been fixed in Kernel 3.0.0-rc3, so its probably only a matter of time until we can use our wireless again...
Let me know if I can help you with any additional information regarding my soft- and hardware configuration in order to make the router firmware more immune to such flaws.
Same thing here. I've iterated all 2.6.39.x (even yesterday's .2) just to end up with dead router. My WNDR3700v1 is running the latest firmware 06-14-11-r17201 but I've had the same problem with every firmware I've tested. There was multiple fixes in iwl* files with .39.2 kernel but still no luck for me. Also 3.0-rc3 according to some sources is not the answer.
My card is "Network controller: Intel Corporation Centrino Advanced-N 6200 (rev 35)" on Mageia 1.
In my opinion the client should not break router otherwise simple DoS is much too easy. _________________ ---
Netgear WNDR3700v1 + DD-WRT always the latest
Looks like the problem is with 802.11n code since using "options iwlagn 11n_disable=1" at client end helps. _________________ ---
Netgear WNDR3700v1 + DD-WRT always the latest
Looks like the problem is with 802.11n code since using "options iwlagn 11n_disable=1" at client end helps.
Seems to do the trick. Connection looks stable and iwconfig doesn't give me any TX excessive retries anymore. Lots of Invalid miscs, though, but no more router breakdowns, at least not for now.
ddwrt: DD-WRT v24SP2-MULTI (12/17/10) std
router: WZR-HP-AG300H
driver: iwlagn
kernels: 2.6.39 and up, including 3.0rc7
how on earth it CRASHES the router, i dont know. almost certainly this is a bug in ddwrt, because it affects multiple routers.
there is also probably a bug in some 802.11n code in the kernel, but either way, it is certainly something that must be fixed in ddwrt- no wifi client should be able to take out a router.
Interestingly, this doesn't seem to kill the router using the 5 ghz band for me. Reliably crashes the router on 2.4 ghz. Of course, 5 ghz on the iwlagn/dd-wrt combo has terrible reception and is unreliable even from 2 feet away, so maybe this is only a coincidence.
I am also affected by this problem. I have upgraded kernel of my Fedora 15 from 2.6.38 to 2.6.40 today and now router crashes almost instantly as soon as I associate laptop with it. It works OK when I boot back into 2.6.38 kernel.