Wifi Disconnects

when it disconnects, run:

sudo lshw -C network; dmesg | tail; lsb_release -a; uname -a

What is output?

Thanks

Can you also run:

sudo iwlist scan

There may be interference from other networks this should tell us.

As I triggred this command the network came back before the command got completely exicuted.

Outcome of the command:
sudo lshw -C network; dmesg | tail; lsb_release -a; uname -a

  *-network
       description: Ethernet interface
       product: 88E8038 PCI-E Fast Ethernet Controller
       vendor: Marvell Technology Group Ltd.
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: eth0
       version: 14
       serial: 00:1b:24:21:ac:55
       capacity: 100Mbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm vpd msi pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=sky2 driverversion=1.30 latency=0 link=no multicast=yes port=twisted pair
       resources: irq:43 memory:d0700000-d0703fff ioport:2000(size=256)
  *-network
       description: Wireless interface
       product: WiFi Link 5100
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlan0
       version: 00
       serial: 00:16:ea:5b:14:14
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlwifi driverversion=3.5.0-21-generic firmware=8.83.5.1 build 33692 ip=192.168.1.5 latency=0 link=yes multicast=yes wireless=IEEE 802.11abgn
       resources: irq:44 memory:d0a00000-d0a01fff
[16601.036495] sr 1:0:0:0: [sr0] Unhandled sense code
[16601.036504] sr 1:0:0:0: [sr0]
[16601.036508] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[16601.036513] sr 1:0:0:0: [sr0]
[16601.036516] Sense Key : Blank Check [current]
[16601.036524] sr 1:0:0:0: [sr0]
[16601.036528] Add. Sense: No additional sense information
[16601.036533] sr 1:0:0:0: [sr0] CDB:
[16601.036536] Read(10): 28 00 00 00 00 00 00 00 01 00
[16601.036553] end_request: I/O error, dev sr0, sector 0
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 12.10
Release: 12.10
Codename: quantal
Linux inderjit-Aspire-5580 3.5.0-21-generic #32-Ubuntu SMP Tue Dec 11 18:51:59 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

On runing :sudo iwlist scan, there are two out comes, 1st one shoes output and the second one shows error:

1st time:
eth0 Interface doesn't support scanning.

lo Interface doesn't support scanning.

wlan0 Scan completed :
          Cell 01 - Address: 00:FD:07:9C:7B:73
                    Channel:6
                    Frequency:2.437 GHz (Channel 6)
                    Quality=70/70 Signal level=-29 dBm
                    Encryption key:off
                    ESSID:"Bedi-ADSL"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s
                    Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s
                              36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=0000001ee86acf1f
                    Extra: Last beacon: 28ms ago
                    IE: Unknown: 0009426564692D4144534C
                    IE: Unknown: 010482848B96
                    IE: Unknown: 030106
                    IE: Unknown: 2A0104
                    IE: Unknown: 32080C1218243048606C
          Cell 02 - Address: 0C:D2:B5:00:CB:40
                    Channel:1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=27/70 Signal level=-83 dBm
                    Encryption key:on
                    ESSID:"dont u try to conect"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s
                    Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s
                              36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=000000002d5e911c
                    Extra: Last beacon: 5760ms ago
                    IE: Unknown: 0014646F6E7420752074727920746F20636F6E656374
                    IE: Unknown: 010482848B96
                    IE: Unknown: 030101
                    IE: WPA Version 1
                        Group Cipher : TKIP
                        Pairwise Ciphers (1) : TKIP
                        Authentication Suites (1) : PSK
                    IE: Unknown: 050400010000
                    IE: Unknown: 2A0104
                    IE: Unknown: 32080C1218243048606C
          Cell 03 - Address: 0C:D2:B5:00:CB:41
                    Channel:1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=26/70 Signal level=-84 dBm
                    Encryption key:on
                    ESSID:""
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s
                    Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s
                              36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=000000002d5e958d
                    Extra: Last beacon: 5756ms ago
                    IE: Unknown: 0000
                    IE: Unknown: 010482848B96
                    IE: Unknown: 030101
                    IE: Unknown: 050400010000
                    IE: Unknown: 2A0104
                    IE: Unknown: 32080C1218243048606C
          Cell 04 - Address: 00:1B:57:DC:F3:F1
                    Channel:1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=27/70 Signal level=-83 dBm
                    Encryption key:on
                    ESSID:"RAJU"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s
                              24 Mb/s; 36 Mb/s; 54 Mb/s
                    Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s
                    Mode:Master
                    Extra:tsf=0000000045835187
                    Extra: Last beacon: 5756ms ago
                    IE: Unknown: 000452414A55
                    IE: Unknown: 010882848B962430486C
                    IE: Unknown: 030101
                    IE: Unknown: 050400010000
                    IE: Unknown: 2A0100
                    IE: Unknown: 2F0100
                    IE: Unknown: 32040C121860
                    IE: Unknown: DD090010180200F4000000
          Cell 05 - Address: A0:21:B7:A8:2A:3E
                    Channel:2
                    Frequency:2.417 GHz (Channel 2)
                    Quality=30/70 Signal level=-80 dBm
                    Encryption key:on
                    ESSID:"Bunny"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 18 Mb/s
                    Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=00000005f2266d80
                    Extra: Last beacon: 5704ms ago
                    IE: Unknown: 000542756E6E79
                    IE: Unknown: 010882848B960C121824
                    IE: Unknown: 030102
                    IE: Unknown: 0706444520010D14
                    IE: IEEE 802.11i/WPA2 Version 1
                        Group Cipher : CCMP
                        Pairwise Ciphers (1) : CCMP
                        Authentication Suites (1) : PSK
                    IE: Unknown: 2A0100
                    IE: Unknown: 32043048606C
                    IE: Unknown: DD180050F2020101820003A4000027A4000042435E0062322F00
                    IE: Unknown: DD1E00904C334E111BFF00000000000000000000000000000000000000000000
                    IE: Unknown: 2D1A4E111BFF00000000000000000000000000000000000000000000
                    IE: Unknown: DD1A00904C34020D0A00000000000000000000000000000000000000
                    IE: Unknown: 3D16020D0A00000000000000000000000000000000000000
                    IE: Unknown: DD0900037F01010000FF7F
                    IE: Unknown: DD0A00037F04010002004000
                    IE: Unknown: DD8B0050F204104A0001101044000102103B0001031047001000000000000010000000A021B7A82A3E1021000D4E6574676561722C20496E632E10230009574E523130303076321024000456324831104200046E6F6E651054000800060050F20400011011001B574E5231303030763228576972656C6573732041502D322E344729100800020086103C000103
          Cell 06 - Address: 94:D7:23:09:F5:68
                    Channel:11
                    Frequency:2.462 GHz (Channel 11)
                    Quality=33/70 Signal level=-77 dBm
                    Encryption key:on
                    ESSID:"MTNL"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 9 Mb/s
                              18 Mb/s; 36 Mb/s; 54 Mb/s
                    Bit Rates:6 Mb/s; 12 Mb/s; 24 Mb/s; 48 Mb/s
                    Mode:Master
                    Extra:tsf=000000002f071194
                    Extra: Last beacon: 5288ms ago
                    IE: Unknown: 00044D544E4C
                    IE: Unknown: 010882848B961224486C
                    IE: Unknown: 03010B
                    IE: Unknown: 2A0104
                    IE: Unknown: 32040C183060
                    IE: Unknown: 2D1A6E1117FF000000010000000000000000000000000C0000000000
                    IE: Unknown: 3D160B000100000000000000000000000000000000000000
                    IE: Unknown: 3E0100
                    IE: WPA Version 1
                        Group Cipher : TKIP
                        Pairwise Ciphers (2) : TKIP CCMP
                        Authentication Suites (1) : PSK
                    IE: Unknown: DD180050F2020101000003A4000027A4000042435E0062322F00
                    IE: Unknown: 4A0E14000A002C01C800140005001900
                    IE: Unknown: 7F0101
                    IE: Unknown: DD07000C4304000000
                    IE: Unknown: 0706545700010B10

2nd time: sudo iwlist scan
eth0 Interface doesn't support scanning.

lo Interface doesn't support scanning.

wlan0 Interface doesn't support scanning : Device or resource busy

try:

echo "options iwlwifi 11n_disable=1" | sudo tee /etc/modprobe.d/iwlwifi.conf > /dev/null

reboot to test

I remember using LAN Cable when I migrated to Ubuntu from Windows XP to Ubuntu 9.04, and cursed that I have a Acer Laptop that has this problem, I tested HP Laptop that worked fine with Ubuntu 9.04.

As I Upgraded to 11.04 the isue got resolved automatecally, so something changed with this version that worked fine for me till I upgraded to 12.04.

I have tested the issue with Install CD, the issue resurfaced in 12.04 and workes fine with 11.10.

I have tried the above command and still the issue is same, wifi disconnects regularly.

As I use PPTP VPN to connect to office network, this is very irritating.

I hope to get a solution to this issue or I will have to downgrade to 11.10.

I closed this by accident.

Try changing the wireless transmission channel on your wireless router to channel 8.

Also temporarily disable encryption on your wireless router (for troubleshooting purposes).

Also install wicd as a replacement for NetworkManager.

You can install wicd using this command and using a wired Internet connection:

sudo apt-get update && sudo apt-get install wicd

In the wicd network manager, choose wlan0 as wireless interface name.

Then retest wireless using wicd.

If that does not help, I suggest testing the 64-bit version of the v3.8-rc2-raring kernel which you can get using these commands:

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.8-rc2-raring/linux-headers-3.8.0-030800rc2-generic_3.8.0-030800rc2.201301022235_amd64.deb

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.8-rc2-raring/linux-headers-3.8.0-030800rc2_3.8.0-030800rc2.201301022235_all.deb

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.8-rc2-raring/linux-image-3.8.0-030800rc2-generic_3.8.0-030800rc2.201301022235_amd64.deb

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.8-rc2-raring/linux-image-extra-3.8.0-030800rc2-generic_3.8.0-030800rc2.201301022235_amd64.deb

sudo dpkg -i linux-headers-3.8.0-030800rc2-generic_3.8.0-030800rc2.201301022235_amd64.deb

sudo dpkg -i linux-headers-3.8.0-030800rc2_3.8.0-030800rc2.201301022235_all.deb

sudo dpkg -i linux-image-3.8.0-030800rc2-generic_3.8.0-030800rc2.201301022235_amd64.deb

sudo dpkg -i linux-image-extra-3.8.0-030800rc2-generic_3.8.0-030800rc2.201301022235_amd64.deb

Then reboot and retest wireless using the 3.8.0-030800rc2-generic_3.8.0-030800rc2.201301022235_amd64 kernel.

Hi MArk,
I have tried everything you have sugested and the problem is still there.
:(

I pan to downgrade to Ubuntu 11.10 today but will still waite for some solution for WiFi Disconnecting in Ubuntu 12.10

Oneiric is EOL in April this year. I suggest you try a fresh install of Precise. It is LTS so is supported til April 2017

I have been using 11.4 and it has worked fine for morethan one year now.

Now I have installed 13.10 and the problem is still the same, wifi keps on disconnecting.

I hope I get a solution to this problem.

echo "options iwlwifi 11n_disable=1 swcrypto=1" | sudo tee /etc/modprobe.d/iwlwifi.conf > /dev/null

Run that as one big command, reboot to test.

Before you reply to my problem, please try to understand that I hade the same problem with 9.04 / 9.10 and same issue with
10.04 and 10.10

When I upgraded to 11.04 the issue got resolved and then it worked fine with 11.10 also.

When I upgraded to 12.04 the problem resurfaced, so I had to downgrade.

Now 13.04 now 13.10 also has the same issue so I have to downgrade to 11.04.

There must be something correct with 11.04, how can I identify the prblem and resolve it, it has been morethan 4 years now that my issue is unresolved.

As I am unable to work with 13.10 I am going to downgrade to 11.10.

Please advice if I could extract something / some settings from 11.10 where WiFi works fine and bring the same settings to 13.10 or any new version so that my WiFi works as it worked fine in 11.10.

some times when there is a technical issue occurs in the supply the people who have no experience about these things confuse about this situation and think there is a Wi-Fi issue. like you can see here https://mykitchenfactory.com/