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Unstable internet connection

Posted: Fri Jun 07, 2013 9:54 am
by pierre.drapeau
My pi is connected to the local network of my university by the ethernet port.
I set a static ip address that was given to me especially for the pi , here is my /etc/network/interfaces files :

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static

allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp

I can get the internet for five or ten minutes but then it stop, and i have to reboot my pi each time to make it work again.
Does anybody knows why ?

Re: Unstable internet connection

Posted: Fri Jun 07, 2013 2:21 pm
by FTrevorGowen
Hi Pierre,
Given that my Pi's get their IP addresses (statically) assigned by dhcp from my router I may be wrong (if so, someone will correct me, no doubt) but comparing one of my /etc/network/interfaces files (automatically generated for me) with yours I can see an extra line: "auto eth0" which is not present in mine (the static IP lines are also not present, but I'd expect that). Everything else is the same. (I'm assuming your connection is a "wired" one, not WiFi)

Re: Unstable internet connection

Posted: Fri Jun 07, 2013 4:18 pm
by redhawk
Your interface settings are not so different from mine expect I have an entry for "broadcast" which probably isn't required.
When you connection goes dead there are a few things to try out:
- check your eth0 interface for errors, drops and overruns: ifconfig eth0
A high detection of errors could indicate a signal quality cable issue between your LAN port and gateway machine (try ifdown eth0 and then ifup eth0 instead of performing a reboot).
- ping or traceroute your gateway IP: i.e. ping and traceroute
- check your ARP table during working internet and then after internet goes down: arp
The arp tool displays the physical MAC address of your Pi and the gateway MAC address, this is especially important if you're experiencing ARP poisoning from other user on the local network.
ARP poisoning can do 2 things: a) make your internet stop working b) re-route all your network packets to another machine which can be monitored and then sent to the actual gateway machine.
If you're experiencing an ARP poisoning attack the change of MAC address for your gateway is usually a dead give away. :D

Richard S.

Re: Unstable internet connection

Posted: Mon Jun 10, 2013 8:17 am
by pierre.drapeau
Thanks for your answers ! I'll try that !

Re: Unstable internet connection

Posted: Fri Jul 26, 2013 3:19 pm
by Gustavo_Murta
Pierre try desactivate commands of Wireless configuration .
I think may be conflicts problems with WIFI configurartion.

Code: Select all

#allow-hotplug wlan0
#iface wlan0 inet manual
#wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
#iface default inet dhcp
Change the file too:

Code: Select all

pi@raspberrypi ~ $ sudo nano /etc/resolv.conf

nameserver   (your gateway )
nameserver       (Google link)