dhcp issue: cannot obtain ip on wireless networks

Sarai · 2010-02-26 20:17:02

Hi folks-
I have been using Arch for about a week now and had no initial issues with network setup. However, over the last couple of days I have had issues connecting to wireless networks, first it was just my university's wireless network and now I cannot connect to any but my home network.
I use wicd as my network connection manager, so I initially took this to them. They recommended I try to manually connect using ifconfig, etc and everything went fine until I needed to use dhcp to get an ip address. dhcpcd returned a "timed out" error message and dhclient appeared to be successful (no error message) but when I checked I still did not have an ip address.
I went to my university's head sysadmin (back when it was just a problem there) and she checked the dhcp server and could find no problems with it. In addition, everyone else was getting an ip as normal. Now it's a problem everywhere but home so I doubt it's an external issue.
My wifi card is an Intel Wifi Link 5000 and I used the iwlwifi-5000-ucode driver. As I said, it works perfectly fine on my home network, and the only thing I can see that's different about that network is it's wpa encrypted, all of the other networks I use are open.
I'm new to Arch and have never really needed to troubleshoot a network problem on linux (for my job I was only trained to do windows networking) so I'm not sure what other pieces of information might be necessary for you guys to help me.
I really appreciate in advance the help. I love arch but I really need wireless, if I can't get this fixed I might have to go back to a debian-based system and I don't want to!

n0dix · 2010-02-26 20:37:50

dhcpcd returned a "timed out": this problem was solve with a recent update.

Sarai · 2010-02-26 22:48:41

Well, how recent? I completely updated my system during install last week, and I tried using dhclient as well to no effect...

yvonney · 2010-02-27 07:13:59

yep, can only get online via wired interface.
I'm guessing it only dhcp connections that don't work and that static IP addressing will.
As I can get online wired I've not looked further into this though will when there's time.
There was a similar issue about 3 weeks ago, wicd and dhcp.

Last edited by yvonney (2010-02-27 07:14:31)

Sarai · 2010-02-27 08:10:08

yvonney wrote:

yep, can only get online via wired interface.
I'm guessing it only dhcp connections that don't work and that static IP addressing will.
As I can get online wired I've not looked further into this though will when there's time.
There was a similar issue about 3 weeks ago, wicd and dhcp.

Well, that's not quite my issue either- dhcp works fine on wired and works fine for my home network, which is strange. I don't have a static ip on the home network.

yvonney · 2010-02-27 10:06:50

was just told that wicd in AUR is likely better than the standard repo one.

and yes, I had a rethink on my dhcp thought, i also am fine dhcp with wired, just not wireless.

2_Thumbs_Up · 2010-02-27 10:21:42

n0dix wrote:

dhcpcd returned a "timed out": this problem was solve with a recent update.

How recent? I have the same (or similar) issue as TS. I don't use a network manager and dhcpcd times out so i can't get a ip on wireless nor wired. It was working 2 days ago though.

n0dix · 2010-02-27 14:02:59

Here the bug report: http://bugs.archlinux.org/task/17838
I have dhcpcd 5.1.5 version and don't have this problem because i use dhclient.

@Sarai post some information about the rc.conf file, if you use wicd you get an error or something.

R00KIE · 2010-02-27 15:38:27

yvonney wrote:

was just told that wicd in AUR is likely better than the standard repo one.
and yes, I had a rethink on my dhcp thought, i also am fine dhcp with wired, just not wireless.

Wicd just used whatever it finds in the system, which most probably is dhcpd.

Things may work with dhclient though, from time to time dhcpd seems to be somewhat incompatible with some setups.

Sarai · 2010-02-27 18:36:08

n0dix wrote:

Here the bug report: http://bugs.archlinux.org/task/17838
I have dhcpcd 5.1.5 version and don't have this problem because i use dhclient.
@Sarai post some information about the rc.conf file, if you use wicd you get an error or something.

Okay, I'm booted into windows 7 right this second cause I don't have a net connection otherwise. I can pastebin the entire thing, if you'd like. The error message I get in wicd is "could not obtain IP address".

R00KIE wrote:

Wicd just used whatever it finds in the system, which most probably is dhcpd.
Things may work with dhclient though, from time to time dhcpd seems to be somewhat incompatible with some setups.

I gotta stop posting wall o' text messages- people don't read them, haha!
I tried using dhclient both in the command line (it didn't print any error messages but didn't actually get an ip address) and in wicd ("could not obtain ip address") so I don't actually think my issue is related to the bug in dhcpcd.

I'm going to boot into my arch partition and grab some of my conf files, will post again when I have them.

n0dix · 2010-02-27 18:43:00

Sarai wrote:

n0dix wrote:
Here the bug report: http://bugs.archlinux.org/task/17838
I have dhcpcd 5.1.5 version and don't have this problem because i use dhclient.
@Sarai post some information about the rc.conf file, if you use wicd you get an error or something.
Okay, I'm booted into windows 7 right this second cause I don't have a net connection otherwise. I can pastebin the entire thing, if you'd like. The error message I get in wicd is "could not obtain IP address".

You could try this workaround:

# iwconfig wlan0 power off

Sarai · 2010-02-27 18:55:14

Well, I'm in arch and wireless appears to be working for the moment, thought it wasn't last night... typical right?

Anyway, here's the potentially relevent sections of my rc.conf:

# -----------------------------------------------------------------------
# NETWORKING
# -----------------------------------------------------------------------
#
# HOSTNAME: Hostname of machine. Should also be put in /etc/hosts
#
HOSTNAME="sarai-laptop"

# Use 'ifconfig -a' or 'ls /sys/class/net/' to see all available interfaces.
#
# Interfaces to start at boot-up (in this order)
# Declare each interface then list in INTERFACES
#   - prefix an entry in INTERFACES with a ! to disable it
#   - no hyphens in your interface names - Bash doesn't like it
# 
# DHCP:     Set your interface to "dhcp" (eth0="dhcp")
# Wireless: See network profiles below
#

#Static IP example
#eth0="eth0 192.168.0.2 netmask 255.255.255.0 broadcast 192.168.0.255"
eth0="dhcp"
INTERFACES=(eth0)

# Routes to start at boot-up (in this order)
# Declare each route then list in ROUTES
#   - prefix an entry in ROUTES with a ! to disable it
#
gateway="default gw 192.168.0.1"
ROUTES=(!gateway)
 
# Enable these network profiles at boot-up.  These are only useful
# if you happen to need multiple network configurations (ie, laptop users)
#   - set to 'menu' to present a menu during boot-up (dialog package required)
#   - prefix an entry with a ! to disable it
#
# Network profiles are found in /etc/network.d
#
# This now requires the netcfg package
#
#NETWORKS=(main)

# -----------------------------------------------------------------------
# DAEMONS
# -----------------------------------------------------------------------
#
# Daemons to start at boot-up (in this order)
#   - prefix a daemon with a ! to disable it
#   - prefix a daemon with a @ to start it up in the background
#
DAEMONS=(syslog-ng network netfs crond alsa fam hal mpd)

n0dix · 2010-02-27 19:20:38

Apparently there is not an error in rc.conf file.
A question? This time are you manage the wifi manually, or using wicd?

Sarai · 2010-02-27 19:23:06

That time I did it with wicd.

A thought- my wireless interface is wlan0- does that need to be in the rc.conf file, à la
wlan0="dhcp" ?

n0dix · 2010-02-27 20:37:21

If you use wicd you have some issues in your rc.conf configuration, see please the wiki doc.

Sarai · 2010-03-09 21:41:16

I'm going to bump this because it has gone back to being a mostly intermittent issue, but I often have to reboot when switching to a new access point, even if I've connected to it before. Needless to say, it is frustrating.
Also, I had to make some network configuration changes to my home network to accomodate a new device that doesn't support WPA encryption (thanks, Nintendo, thanks so very much) so now my home network is totally unencrypted (but access is restricted by mac address) and, much to my annoyance, now I can't connect to it AT ALL now matter how many times I reboot it.
To get the obvious out of the way- my mac address is for sure on the allowed list and it gets past the authentication, only to fail when trying to get an IP, as before.

I removed "network" from my daemon's list in the rc.conf as instructed, here's the section as it is now:

DAEMONS=(syslog-ng !network netfs crond alsa fam hal mpd laptop-mode)

I don't know if I need to remove netfs too- I kind of want to keep my command-line config tools for trouble shooting.

I also removed eth0 and wlan0 from my interfaces

INTERFACES=(!eth0 !wlan0)

Please, any thoughts, help etc. Right now I have to do all my internet at home either on my tiny little phone screen or in windows 7 (blech)!

Last edited by Sarai (2010-03-09 21:42:45)

uwinkelvos · 2010-03-10 02:35:47

Sarai wrote:

Also, I had to make some network configuration changes to my home network to accomodate a new device that doesn't support WPA encryption (thanks, Nintendo, thanks so very much) so now my home network is totally unencrypted (but access is restricted by mac address) and,

mac based access control is totaly useless to protect your network against any intruder who is able to start wireshark. WEP encryption will at least sustain some minutes and might therefore scare at least some people off.

much to my annoyance, now I can't connect to it AT ALL now matter how many times I reboot it.
To get the obvious out of the way- my mac address is for sure on the allowed list and it gets past the authentication, only to fail when trying to get an IP, as before.

i have had some trouble with my intel wifi (5100agn?) and my router. dhcpcd did never work, dhclient did work sometimes. But setting up a static ip in wicd is rather simple and never fails. This should be safe to use for your home net and you could ask your admin at the university if there is an ip in a "saved" area you could use.

I removed "network" from my daemon's list in the rc.conf as instructed, here's the section as it is now:
DAEMONS=(syslog-ng !network netfs crond alsa fam hal mpd laptop-mode)
I don't know if I need to remove netfs too- I kind of want to keep my command-line config tools for trouble shooting.
I also removed eth0 and wlan0 from my interfaces
INTERFACES=(!eth0 !wlan0)

if you don't have any samba/cifs or nfs shares in your /etc/fstab you can remove netfs.

Sarai · 2010-03-10 05:35:03

uwinkelvos wrote:

mac based access control is totaly useless to protect your network against any intruder who is able to start wireshark. WEP encryption will at least sustain some minutes and might therefore scare at least some people off.

Well, that's disheartening. Though, to be honest I'm not particularly concerned about someone maliciously hacking my network to get internet or whatever- for one thing the neighbor has an unencrypted "netgear" AP that would be be a much better target! Besides, if they want to go to that much effort than I think they can just HAVE the internet.

uwinkelvos wrote:

i have had some trouble with my intel wifi (5100agn?) and my router. dhcpcd did never work, dhclient did work sometimes. But setting up a static ip in wicd is rather simple and never fails. This should be safe to use for your home net and you could ask your admin at the university if there is an ip in a "saved" area you could use.

I suppose that is an option but I would really like to get dhcp working- I have trouble believing this is a compatibility issue since I had absolutely zero issues with this card prior to using arch- on crunchbang. Now, that was on 2.6.14 kernel, but it's a new card, I doubt they've dropped support for it.

Sarai · 2010-03-15 23:39:18

I'm bumping this, because I have no feasible solution and this is a deal breaker for me. It's started dropping my ip randomly- when it did that a few minutes ago I had to reboot three times before I could get an IP address. A static ip is maybe possible as a fix in some cases but I travel often and rely on public hotspots for a large amount of my internet access.
If I cannot get this to work, soon, I will have to find another operating system which is thoroughly disappointing because I like arch a lot. But my computer doesn't do anything without internet.

yvonney · 2010-03-15 23:53:42

I've not had the time to become at all expert on this.... though I am quite certain it's not much of an 'ARCH' issue... I regularly see all kinds of stuff in other distros that has me going.... whew, love the simplicity and workability of ARCH. I do very much respect that for some situations/persons my enjoyment of 'learning more through having issues' is, well, opposite.

Ok, I have a broadcom card that does the well know thing of swapping from eth0 to eth1 and back (wireless!) almost every reboot. (can't recall the other tech observation I was going to make - may recall later)

So, wicd and dhcpd (for me) need to be tried to see what's what, first. I've gotten good at that! There's been changes with dhcpcd et. al. lately. Genuinely sorry not to be able to add much....

though >>> greener grass elsewhere likely temporary/placebo-esque....

All the above said, ....um, freebsd as a sidekik will be fun someday!!!

read: expert status requires making a whole lotta erRors.

respect to all, and I trust the above isn't seen as rude in not any way. It was my 5 minutes of course..
now back to 'way way toO busy'

UPDATE COMMENT: uhhhhh,,,,, just had a slight more complete read of the above posts. errrrr, whole lotta finer points I've stumbled thru has me quite certain there's rudimentaries that need to be worked thru. Sincere apologies for me taking the time here. Though this may sit well with what could relatively seem: other non-technical posts.

Last edited by yvonney (2010-03-16 00:09:03)

Sarai · 2010-03-16 00:04:46

yvonney wrote:

I've not had the time to become at all expert on this.... though I am quite certain it's not much of an 'ARCH' issue... I regularly see all kinds of stuff in other distros that has me going.... whew, love the simplicity and workability of ARCH. I do very much respect that for some situations/persons my enjoyment of 'learning more through having issues' is, well, opposite.
Ok, I have a broadcom card that does the well know thing of swapping from eth0 to eth1 and back (wireless!) almost every reboot. (can't recall the other tech observation I was going to make - may recall later)
So, wicd and dhcpd (for me) need to be tried to see what's what, first. I've gotten good at that! There's been changes with dhcpcd et. al. lately. Genuinely sorry not to be able to add much....
though >>> greener grass elsewhere likely temporary/placebo-esque....
All the above said, ....um, freebsd as a sidekik will be fun someday!!!
read: expert status requires making a whole lotta erRors.

respect to all, and I trust the above isn't seen as rude in not any way. It was my 5 minutes of course..
now back to 'way way toO busy'

UPDATE COMMENT: uhhhhh,,,,, just had a slight more complete read of the above post. errrrr, whole lotta finer points I've stumbled thru has me quite certain there's rudimentaries that need to be worked thru. Sincere apologies for me taking the time here. Though this may sit well with what could relatively seem: other non-technical posts.

I'm sorry, but I don't have a clue what you are trying to tell me here.

uwinkelvos · 2010-03-16 00:05:37

Is this realy a problem with every single network you connect to? Are there networks from which dhclient is able to retrieve an ip?

does the following work instead of restarting?

sudo /etc/rc.d/wicd stop
sudo modprobe -r iwlagn iwlcore(?!?)
sudo modprobe iwlagn iwlcore(?!?)
sudo /etc/rc.d/wicd start

or this:

sudo killall dhcpcd(/dhclient)
sudo dhcpcd(/dhclient) [wlan0?]

yvonney · 2010-03-16 00:10:53

I'm saying that if you have the time, go deep! Success in all ARCH areas is attainable.

Sarai · 2010-03-16 00:56:39

uwinkelvos wrote:

Is this realy a problem with every single network you connect to? Are there networks from which dhclient is able to retrieve an ip?

Short answer: Yes.
Long answer: Yes, but it's somewhat intermittent- it doesn't seem to matter what network it is, and it does work fine sometimes but more than half the time I have to restart at least once to get an ip.

uwinkelvos wrote:

does the following work instead of restarting?

sudo /etc/rc.d/wicd stop
sudo modprobe -r iwlagn iwlcore(?!?)
sudo modprobe iwlagn iwlcore(?!?)
sudo /etc/rc.d/wicd start

or this:

sudo killall dhcpcd(/dhclient)
sudo dhcpcd(/dhclient) [wlan0?]

I will see if I can force the bug and find out. Thanks!

Sarai · 2010-03-16 01:42:38

[sarai@sarai-laptop ~]$ sudo killall dhclient
Password: 
dhclient: no process found
[sarai@sarai-laptop ~]$ sudo /etc/rc.d/wicd stop
:: Stopping wicd Daemon                                                  [DONE] 
[sarai@sarai-laptop ~]$ sudo modprobe -r iwlagn iwlcore
[sarai@sarai-laptop ~]$ sudo modprobe iwlagn iwlcore
FATAL: Error inserting iwlagn (/lib/modules/2.6.32-ARCH/kernel/drivers/net/wireless/iwlwifi/iwlagn.ko): Unknown symbol in module, or unknown parameter (see dmesg)
[sarai@sarai-laptop ~]$ sudo modprobe iwlcore
[sarai@sarai-laptop ~]$ sudo /etc/rc.d/wicd start
:: Starting wicd Daemon                                                  [DONE] 
[sarai@sarai-laptop ~]$ sudo modprobe iwlagn
[sarai@sarai-laptop ~]$

After I started the wicd Daemon I was able to open wicd but it did not show any networks. So I retried "sudo modprobe iwlagn" after which it showed networks. However, when I tried to join one it claimed that the "wicd daemon had been stopped" and then locked up. I had to kill wicd-client and restart the daemon (killall wicd-client && wicd) to finally get it working, and then it was still unable to get an ip.

Last edited by Sarai (2010-03-16 01:44:07)

Arch Linux

#1 2010-02-26 20:17:02

dhcp issue: cannot obtain ip on wireless networks

#2 2010-02-26 20:37:50

Re: dhcp issue: cannot obtain ip on wireless networks

#3 2010-02-26 22:48:41

Re: dhcp issue: cannot obtain ip on wireless networks

#4 2010-02-27 07:13:59

Re: dhcp issue: cannot obtain ip on wireless networks

#5 2010-02-27 08:10:08

Re: dhcp issue: cannot obtain ip on wireless networks

#6 2010-02-27 10:06:50

Re: dhcp issue: cannot obtain ip on wireless networks

#7 2010-02-27 10:21:42

Re: dhcp issue: cannot obtain ip on wireless networks

#8 2010-02-27 14:02:59

Re: dhcp issue: cannot obtain ip on wireless networks

#9 2010-02-27 15:38:27

Re: dhcp issue: cannot obtain ip on wireless networks

#10 2010-02-27 18:36:08

Re: dhcp issue: cannot obtain ip on wireless networks

#11 2010-02-27 18:43:00

Re: dhcp issue: cannot obtain ip on wireless networks

#12 2010-02-27 18:55:14

Re: dhcp issue: cannot obtain ip on wireless networks

#13 2010-02-27 19:20:38

Re: dhcp issue: cannot obtain ip on wireless networks

#14 2010-02-27 19:23:06

Re: dhcp issue: cannot obtain ip on wireless networks

#15 2010-02-27 20:37:21

Re: dhcp issue: cannot obtain ip on wireless networks

#16 2010-03-09 21:41:16

Re: dhcp issue: cannot obtain ip on wireless networks

#17 2010-03-10 02:35:47

Re: dhcp issue: cannot obtain ip on wireless networks

#18 2010-03-10 05:35:03

Re: dhcp issue: cannot obtain ip on wireless networks

#19 2010-03-15 23:39:18

Re: dhcp issue: cannot obtain ip on wireless networks

#20 2010-03-15 23:53:42

Re: dhcp issue: cannot obtain ip on wireless networks

#21 2010-03-16 00:04:46

Re: dhcp issue: cannot obtain ip on wireless networks

#22 2010-03-16 00:05:37

Re: dhcp issue: cannot obtain ip on wireless networks

#23 2010-03-16 00:10:53

Re: dhcp issue: cannot obtain ip on wireless networks

#24 2010-03-16 00:56:39

Re: dhcp issue: cannot obtain ip on wireless networks

#25 2010-03-16 01:42:38

Re: dhcp issue: cannot obtain ip on wireless networks

Board footer