Erratic Wifi

mikeb1986 · 04-22-2015, 01:46 AM

Have had ongoing problems with wifi since I built my PC. It was like it is now when I first built it, I tried bits I found online to try and fix it and evntually it just started working out of the blue, when I hadn't changed anything. A few weeks ago it just reverted to how it was before

Very rarely it works normally, except it will only see my network (always about 60-70% strength) and not the other 3 in range
Sometimes it will say it is connected but not be able to download anything, and wont even load up the router homepage
Sometimes it connect and run for a few minutes before dropping and not being able to reconnect
Most often it will see my network and all others in range but wont connect
Sometimes it wont see my network at all, but will see others in range
Sometime network manager wont even show wireless up as an option just "nwtwork cable unplugged"

My 2 HDDs are on Mint 17.1, one is 64bit one 32bit. Motherboard is Gigabyte GA-970A-DS3P. I have 3 wifi adapters, one belkin, one realtek, and one "Think Penguin" one I bought especially from USA thinking it would be an easy fix. All have same problem, but all work on my other older PC properly with about 50-60% signal strength (same OS 32 bit)

I have no idea where to start

RMLinux · 04-22-2015, 03:32 AM

to start search in google a lot of wireless commands in Backtrack :-) search for ifconfig, those networking file eth0,...scripts...lsusb, lspci..wlan..etc..
https://wiki.archlinux.org/index.php..._configuration

devnod · 04-22-2015, 03:57 AM

Brand names don't really help..can you plug them in and do an "lspci" command? If you copy the information about the chipsets themselves it would be helpful. Many times these issues are caused by modules loading into the kernel which need to have flags adjusted, most commonly related to the power management systems.

As I am not a Mint user I am not really sure how your problem would be tackled, but those who do will need more information.

RMLinux · 04-22-2015, 03:59 AM

try also "lspci -vv" display verbose and display even more information

mikeb1986 · 04-22-2015, 04:06 AM

I will post info tonight I was in a rush this morning or would have included more details

ardvark71 · 04-22-2015, 11:57 AM

Hi...

I know a "mikeb" on another forum, wonder if you're the same guy?

Please try this command if we're talking about PCI adapters...

Code:

lspci -nnk | grep -i net -A2

If these are usb adapters...

Code:

lsusb

However, since all three are having this problem, yet work fine another system with the same OS, my guess at this point would be either some issue with the motherboard or some kind of settings adjustment.

Regards...

mikeb1986 · 04-22-2015, 01:57 PM

aardvard, its unlkiely you already know me, there aren't really any forums I visit often enough

They are all usb adapters.
I have a bit more information. Have just included what I assume is relevant. This is with the new Think Penguin adapter in, supposedly linux friendly. It could see my network with very poor signal strength and wouldnt connect. No sign of the other networks I know are there.

Code:

mike@mike-study ~ $ lsusb
Bus 003 Device 002: ID 0cf3:9271 Atheros Communications, Inc. AR9271 802.11n

Code:

mike@mike-study ~ $ lspci -vv
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06)
	Subsystem: Gigabyte Technology Co., Ltd Motherboard
	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 73
	Region 0: I/O ports at d000 [size=256]
	Region 2: Memory at fe800000 (64-bit, non-prefetchable) [size=4K]
	Region 4: Memory at d0000000 (64-bit, prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: r8169

00:00.2 IOMMU: Advanced Micro Devices, Inc. [AMD/ATI] RD990 I/O Memory Management Unit (IOMMU)
	Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] RD990 I/O Memory Management Unit (IOMMU)
	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-
	Interrupt: pin A routed to IRQ 0
	Capabilities: <access denied>

Code:

mike@mike-study ~ $ ifconfig
eth0      Link encap:Ethernet  HWaddr fc:aa:14:29:af:06  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:192 errors:0 dropped:0 overruns:0 frame:0
          TX packets:192 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:36551 (36.5 KB)  TX bytes:36551 (36.5 KB)

wlan3     Link encap:Ethernet  HWaddr 30:14:4a:7d:b5:80  
          inet6 addr: fe80::3214:4aff:fe7d:b580/64 Scope:Link
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:79 errors:0 dropped:0 overruns:0 frame:0
          TX packets:132 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:7377 (7.3 KB)  TX bytes:26973 (26.9 KB)

Have included the IOMMU because I know I did something with that before when I had trouble. Something along the lines of disabling IOMMU in linux and enabling it from the BIOS menu, an idea taken from another forum search that didnt work for me

Any other helpful commands I will post any info needed, its a bit of a pain as I cant find an ethernet cable in the house so it will be weekend before I can get the PC online at all. Thanks

Shadow_7 · 04-23-2015, 02:42 AM

Quote:

Originally Posted by mikeb1986

They are all usb adapters.

There's your problem.

(or not)

A lot of USB chipsets are underpowered, the usb bus, not the devices. And USB based WIFI is known to have poor signal strength like issues. You can try using them in a powered USB hub to ensure that they can get access to more juice than the 500mA or less that the onboard chipset of many motherboards provide (divided by how many devices are drawing power from the same bus). This should also allow you get them away from other electronics. Like a large LED display device. Some LED light bulbs generate radio waves that can also block signals like ATSC broadcasts and WIFI. So check if the issue goes away when you turn off the lights. And perhaps buy a different brand of LED bulb for that room or revert to the older technologies.

I tend to ethernet to a stand alone router in bridge mode. Like an asus rt-n12 or rt-n16. For $40-$80 I can get a wifi dongle of sorts that supports up to 4 devices connected via ethernet cables. And I can hang it up high to avoid having the signal go through furniture.

mikeb1986 · 04-25-2015, 03:43 PM

Thanks Shadow
I have tested your theroy, by moving the PC to the kitchen (where router is) and had no problems connecting on wifi. I never thought about range as a problem since it all works on the old pc (on the same desk) I have ordered a PCI wifi card to try, and an asus rtn12. If the PCI card works I can always use the router as a booster in front room. I'll no doubt be back in a few days with thanks or more questions