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Old 07-02-2011, 06:33 AM   #1
LQ Newbie
Registered: Jul 2011
Posts: 19

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Ubuntu Natty teething problems - wireless losing connectivity on Samsung N130

Hi all,

Firstly I'm still pretty new to linux so please bear with me.

I have a fresh install of 11.04 natty running on my N130.

lsmod shows

~$ lsmod | grep r81
r8192e_pci 251260 0
r8192se_pci 482505 0
cfg80211 156212 1 r8192se_pci

However the se driver doesn't do anything, I usually just modprobe -r it and the cfg 80211 goes with it.

After about 5 mins inactivity I cannot ping the router(and obviously anything beyond this). I can ping loopback. I'm not 100% sure but the connectivity seems to drop if I let the screensaver come on and I have to unlock the netbook.

I can rmmod r8192e_pci and then modprobe r8192e_pci and it works again until the next timeout but this is extremely annoying. When it drops I'm still showing as connected and iwconfig shows no changes.

I've tried blacklisting the se driver by adding "blacklist r8192se_pci" to /etc/modprobe.d/blacklist.conf but it doesn't seem to stop the driver from loading.

"sudo network-manager stop" produces the same symptoms, can somebody maybe talk me through going around network manager to see if this solves the issue?

I've tried adding "auto wlan0" and "iface wlan0 inet dhcp" with the wpa ssid and passphrase and running "ifup wlan0" but it tells me it's already up and I can't connect.

"dhclient wlan0" does not renew ip address after stopping network manager. I have set the essid using iwconfig but cannot add the wpa2 key, can anyone tell me how to do this via command line? ifconfig only shows loopback interface when network manager is stopped, I assume this is because I haven't managed to add the wpa key.

For completion lspci and modprobe -l | grep r81 shown below

~$ lspci | grep Realtek
02:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8192E Wireless LAN Controller (rev 01)
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 02)

~$ modprobe -l | grep r81
Old 07-02-2011, 11:55 AM   #2
LQ Newbie
Registered: Jul 2011
Posts: 19

Original Poster
Rep: Reputation: Disabled
So after disabling network manager and using the /etc/network/interfaces file the same issue is happening. However ifdown wlan0 followed by ifup wlan0 fixes it instantly.

I'm thinking this could therefore be caused by some idle power-saving mode enabled in natty by default. Anyone know where I would look for a log of such an event or how to force my wireless to keep refreshing itself?

liam@n3tb00k:~$ ifconfig
lo Link encap:Local Loopback
inet addr: Mask:
inet6 addr: ::1/128 Scope:Host
RX packets:1012 errors:0 dropped:0 overruns:0 frame:0
TX packets:1012 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:77936 (77.9 KB) TX bytes:77936 (77.9 KB)

wlan0 Link encap:Ethernet HWaddr 00:24:d2:db:df:15
inet addr: Bcast: Mask:
inet6 addr: fe80::224:d2ff:fedb:df15/64 Scope:Link
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)
Interrupt:16 Memory:f8178000-f8178100

liam@n3tb00k:~$ ping
PING ( 56(84) bytes of data.
64 bytes from icmp_req=6 ttl=254 time=45.4 ms
64 bytes from icmp_req=12 ttl=254 time=3705 ms
64 bytes from icmp_req=13 ttl=254 time=2705 ms
64 bytes from icmp_req=15 ttl=254 time=706 ms
64 bytes from icmp_req=16 ttl=254 time=285 ms
64 bytes from icmp_req=17 ttl=254 time=129 ms
64 bytes from icmp_req=22 ttl=254 time=4100 ms
64 bytes from icmp_req=25 ttl=254 time=1076 ms
64 bytes from icmp_req=26 ttl=254 time=69.4 ms
--- ping statistics ---
26 packets transmitted, 9 received, 65% packet loss, time 25108ms
rtt min/avg/max/mdev = 45.413/1424.838/4100.174/1540.215 ms, pipe 5
liam@n3tb00k:~$ ping
PING ( 56(84) bytes of data.
64 bytes from ( icmp_req=1 ttl=59 time=447 ms
64 bytes from ( icmp_req=2 ttl=59 time=16.9 ms
64 bytes from ( icmp_req=3 ttl=59 time=91.1 ms
64 bytes from ( icmp_req=4 ttl=59 time=26.8 ms

Link encap - ethernet ... is this my problem?

Last edited by Linuxstudent; 07-02-2011 at 12:09 PM.


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