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Basically I'm an information security student and I was trying to set up snort, I needed to turn off “Large Receive Offload” (lro) and “Generic Receive Offload” (gro) to get snort working which I have successfully done and edited /etc/network/interfaces and everything was working fine.

Minutes later my wifi went down and I have tried every single command to get it back up without any use, I undid all the changes I have made yet its not working.

when I type iwconfig this is what I get

lo no wireless extensions.

wlo1 IEEE 802.11bgn ESSID:o ff/any 
Mode:Managed Access Point: Not-Associated       Tx-Power=0 dBm 
Retry short limit:7 RTS thr:o ff Fragment thr: off
Encryption key:o ff
Power Management:o ff

eno1 no wireless extensions.

I tried to get the network up as well but I get error: input/output.

I've been going through this for about 6 hours now without success, my wired connection works but wireless doesn't.

Wild Man
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Mohamed
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2 Answers2

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Have you tried to check whether the device is for some reason blocked by RF-KILL? Is there a physical switch for WiFi on your computer (mine is FnF7 for "airplane mode" which is triggered by default on new Ubuntu installations, every time). Try:

rfkill list all

Also, Make sure you are using 

sudo ifconfig wlan0 up
sudo iwconfig wlan0 essid (network) key (passwd)
sudo dhclient wlan0

This is the only way I've been able to (consistently) get WiFi back up and running. If you run the command lshw and see a wireless interface, you know it's at least detected... so you are safe.

*Substitute wlan0 for whatever the name of your wireless device is

muru
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P Smith
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  • tried rfkill list all repeatedly, i get – Mohamed Jun 12 '16 at 23:27
  • What is it that you get? – P Smith Jun 12 '16 at 23:30
  • tried rfkill list all repeatedly, i get 0: phy0: Wireless LAN Soft blocked: no Hard blocked: no and same with up command i get

    SIOCSIFFLAGS: Input/output error

    and for sudo iwconfig wlan0 essid (network) key (passwd)

    i keep getting invalid argument for my password

    lastly sudo dhclient wlan0

    i get RTNETLINK answers: Input/output error

     – Mohamed Jun 12 '16 at 23:34
  • I forgot to specify (although I'm sure you did): replace (network) with network name, and (passwd) with that network's password. This doesn't seem to be the issue in your case, but definitely make sure that's right, as it's a logical first step in troubleshooting your issue. – P Smith Jun 12 '16 at 23:39
  • Do you see your wireless device when you run sudo lshw? – P Smith Jun 12 '16 at 23:40
  • yeah i replaced the name and password, and yup its right there but i dont seem to be able to get it working

    -network DISABLED description: Wireless interface product: RT3290 Wireless 802.11n 1T/1R PCIe

     – Mohamed Jun 12 '16 at 23:43
  • Well... are you using network-manager (or network-manager-gnome)? I solved a few WiFi issues by simply switching to wicd sudo apt-get install wicd – P Smith Jun 12 '16 at 23:49
  • I understand that's not as much as an answer as it is a workaround, but it's a solution nonetheless (potentially)... – P Smith Jun 12 '16 at 23:49
  • i did that, wicd couldnt find wireless network either :) – Mohamed Jun 12 '16 at 23:51
  • geez... well have you tried reverting back to original settings (before installation of snort)... since THAT configuration worked? Are these the only new packages: libdaq2 oinkmaster snort snort-common snort-common-libraries snort-rules-default ? – P Smith Jun 13 '16 at 00:19
  • I see I'm not likely to be able to help on this one... those are my intermediate troubleshooting skills. I would try to uninstall the program and see if that fixes it. I could try to install it and see if it breaks anything if I get a VM up and running... can't afford it otherwise (I'm a web developer) :D but... I'm trying to research it some more for you. – P Smith Jun 13 '16 at 00:21
  • i reverted /etc/network/interfaces to how it was even removed ethtool incase somehow it was the cause, and i had to add many new packages for snort but everything was working just fine after every step until i decided to edit the interface file and turn off both IRO and GRO. – Mohamed Jun 13 '16 at 00:23
  • thanks for the effort mate i truly appreciate it! i really don't want to uninstall ubnutu and reinstall it so many stuff i have going on on it and no dont go as far as installing it just to check leave it mate dont bother yourself you did more than enough – Mohamed Jun 13 '16 at 00:25
  • haha well, no worries at all! Surely someone will come along and be able to answer, maybe a sysadmin who's used snort... surely you can't be the ONLY one! Cheers, and best of luck with it then. – P Smith Jun 13 '16 at 00:27
  • Cheers! it's been fun seeing you getting frustrated with me about this! best of luck with your web developing applications as well i don't think you're having it any easier than me – Mohamed Jun 13 '16 at 00:34
  • :D True story my friend. We love the struggle. – P Smith Jun 13 '16 at 00:37
-1

okay so, after two days and countless hours spent trying to get the wireless back up its finally working. Not sure if this is an actual answer to the question but here you go this is how i got it working again incase someone is ever in the same frustrating spot as me. i made sure i deleted every single package i have installed for snort, including

flex
bison
tcpdumb
libpac
pulledpork
pcap
pcre
libdnet

and then ran this command to make sure i delete all traces of snort and its dependencies 

sudo apt-get remove --auto-remove snort

and did the same command for every single package up there

then i rebooted the pc, still nothing worked. Then giving up i decided to format ubnutu, so i log into my windwos since i dual boot for the first time since this whole fiasco happened and that was the solution. Somehow, logging into my windows participation then back into my ubuntu fixed the issue.

i wanna thanks p Smith for his help, he's the one who suggested to revert back to settings before snort and remove all packages which could have helped solve the problem.

if anyone faces similar problem, please up this post or pm me and ill try to guide you through this.

muru
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