Thread: Can't connect to WiFi via command line (iwconfig/ifconfig)

hi,

i'm unable connect unsecured wireless network (or wireless network) on laptop, though network manager connects fine. (also, phone , other computers have no problem connecting.) i've googled extensively , have found no answers.


computer: toshiba nb505 netbook, running fresh install of ubuntu 11.04

code:

$ lspci | grep network 07:00.0 network controller: realtek semiconductor co., ltd. rtl8188ce 802.11b/g/n wifi adapter (rev 01)

initial settings on startup (before logging gnome , having network manager start)

code:

$ ifconfig wlan0 wlan0     link encap:ethernet  hwaddr 7c:4f:b5:73:b4:be             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) $ iwconfig wlan0 wlan0     ieee 802.11bgn  essid:off/any             mode:managed  access point: not-associated   tx-power=20 dbm              retry  long limit:7   rts thr=2347 b   fragment thr:off           power management:off

attempting configure wireless on command line:

code:

$ sudo iwlist wlan0 scan wlan0     scan completed : edited show relevant network           cell 04 - address: 00:16:01:12:e7:5e                     channel:6                     frequency:2.437 ghz (channel 6)                     quality=64/70  signal level=-46 dbm                       encryption key:off                     essid:"foobarweb"                     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=00000000b6d6419d                     extra: last beacon: 224ms ago                     ie: unknown: 0009666f6f626172776562                     ie: unknown: 010882848b962430486c                     ie: unknown: 030106                     ie: unknown: 2a0102                     ie: unknown: 2f0102                     ie: unknown: 32040c121860                     ie: unknown: dd090010180201f0000000                     ie: unknown: dd180050f2020101800003a4000027a4000042435e0062322f00 $ # @ point, seem me need configure wlan0 use appropriate essid, since in managed mode , there no encryption $ sudo iwconfig wlan0 essid "foobarweb" $ sudo iwconfig wlan0 # double check essid set wlan0     ieee 802.11bgn  essid:off/any             mode:managed  access point: not-associated   tx-power=20 dbm              retry  long limit:7   rts thr=2347 b   fragment thr:off           encryption key:off           power management:off $ # not sure why wasn't set. try setting more things: $ sudo iwconfig wlan0 key open mode managed essid "foobarweb" channel 6 $ sudo iwconfig wlan0 # check see if settings took hold time wlan0     ieee 802.11bgn  essid:"foobarweb"             mode:managed  frequency:2.437 ghz  access point: not-associated              tx-power=20 dbm              retry  long limit:7   rts thr=2347 b   fragment thr:off           encryption key:off           power management:off $ # ok, everything's set, let's try ip address $ sudo dhclient -v wlan0   internet systems consortium dhcp client 4.1.1-p1 copyright 2004-2010 internet systems consortium. rights reserved. info, please visit https://www.isc.org/software/dhcp/  listening on lpf/wlan0/7c:4f:b5:73:b4:be sending on   lpf/wlan0/7c:4f:b5:73:b4:be sending on   socket/fallback dhcpdiscover on wlan0 255.255.255.255 port 67 interval 3 dhcpdiscover on wlan0 255.255.255.255 port 67 interval 6 dhcpdiscover on wlan0 255.255.255.255 port 67 interval 11 dhcpdiscover on wlan0 255.255.255.255 port 67 interval 17 dhcpdiscover on wlan0 255.255.255.255 port 67 interval 15 dhcpdiscover on wlan0 255.255.255.255 port 67 interval 9 no dhcpoffers received. no working leases in persistent database - sleeping.

this i'm stuck. i've checked syslog when network manager connects , seems dhcpoffer , ip address every time.

way, here's iwconfig/ifconfig settings set when network manager used:

code:

$ sudo ifconfig wlan0 wlan0     link encap:ethernet  hwaddr 7c:4f:b5:73:b4:be             inet addr:192.168.1.119  bcast:192.168.1.255  mask:255.255.255.0           inet6 addr: fe80::7e4f:b5ff:fe73:b4be/64 scope:link           broadcast running multicast  mtu:1500  metric:1           rx packets:8 errors:0 dropped:0 overruns:0 frame:0           tx packets:37 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            rx bytes:1404 (1.4 kb)  tx bytes:9312 (9.3 kb) $ sudo iwconfig wlan0 wlan0     ieee 802.11bgn  essid:"foobarweb"             mode:managed  frequency:2.437 ghz  access point: 00:16:01:12:e7:5e              bit rate=5.5 mb/s   tx-power=20 dbm              retry  long limit:7   rts thr=2347 b   fragment thr:off           encryption key:off           power management:off           link quality=70/70  signal level=-37 dbm             rx invalid nwid:0  rx invalid crypt:0  rx invalid frag:0           tx excessive retries:0  invalid misc:0   missed beacon:0

[edit]
i've started wireshark on both laptop , one, monitoring dhcp packets. network manager initializing wireless configuration, see normal sequence of dhcp packets on both systems. manual approach above, see no packets whatsoever. when "dhclient" shows sending dhcpdiscover packets, see nothing in wireshark.

manual methods iwconfig, etc. unlikely work long network manager running. nm has taken control , not respond set of hands on controls. might able remove nm startup programs , done, why if nm connects expected. check with:

code:

ps aux | grep -i network

if old-school , want things way, i'd suggest removing nm altogether.

in various , growing collection of systems, both nm , manual methods, nm removed, work perfectly.

Forum The Ubuntu Forum Community Ubuntu Official Flavours Support Networking & Wireless [SOLVED] Can't connect to WiFi via command line (iwconfig/ifconfig)

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