Wireless: DHCP IP lease attempt failed

mamr · 2009-05-11 08:57:36

Hi,
did an upgrade today and now I get the above error message, when trying to connect to my router with netcfg2. The exact error message is like following:

[root@tux matthias]# 
 [root@tux matthias]# netcfg2 home
dhcpcd: wlan0: ignoring DHCP message; no Server ID
dhcpcd: wlan0: ignoring DHCP message; no Server ID
dhcpcd: wlan0: ignoring DHCP message; no Server ID
dhcpcd: timed out
:: home up  - DHCP IP lease attempt failed                               [FAIL]

My /etc/network.d/home looks like that:

CONNECTION="wireless"
INTERFACE=wlan0
QUIRKS=(prescan preessid)
SCAN="yes"
SECURITY="wpa"
ESSID="wirelessbox"
KEY="..."
IP="dhcp"
TIMEOUT=30

I did nothing except updating. Everything worked fine before that.

Any hints?

EDIT: I added the QUIRKS line after getting the error message, because a guy on IRC suggested that. This didn't help either.

Last edited by mamr (2009-05-11 12:46:11)

karol · 2009-05-11 11:08:13

0. Could you please add to the title that it's a wlan issue?

mamr wrote:

Hi,
did an upgrade today

I had to sell my crystall ball to pay the rent, so I have no way of finding out what did you upgrade ... unless you tell me.

mamr wrote:

I did nothing except updating

Any chances that the upgrade changed your settings? Have you backed them up before upgrading? I'm new here, but I think you can preserve certain parts of your system when doing upgrades.

mamr · 2009-05-11 12:49:31

karol wrote:

0. Could you please add to the title that it's a wlan issue?

Did so.

karol wrote:

I had to sell my crystall ball to pay the rent, so I have no way of finding out what did you upgrade ... unless you tell me.

I did a "pacman -Syu"

karol wrote:

Any chances that the upgrade changed your settings? Have you backed them up before upgrading? I'm new here, but I think you can preserve certain parts of your system when doing upgrades.

I do have a backup with my settings from a few days ago. Tested it with this configuration and nothing happened either. I compared my latest settings with the "old" ones (= the ones from the backup) and nothing seems to be changed.

iphitus · 2009-05-11 13:04:43

Look in your pacman log. I'm guessing it was the dhcpcd update.

karol · 2009-05-11 13:32:51

mamr wrote:

I did a "pacman -Syu"

<sigh>
A drunken guy gets into a taxi.
- Where to - asks the driver.
- Home! <hiccup>
- Could you please be more precise, sir?
- Straight to the bedroom, please! <collapses>

1. Simple google querry returned this
http://roy.marples.name/projects/dhcpcd … 8ea5e93379
so ti may be a bug of some kind. You can also check the bugtracker, but I don't see anything relevant there ... yet.

I no nothing about wireless, so I think you'll have to get assistance from someone else.

mamr · 2009-05-11 14:29:42

iphitus wrote:

Look in your pacman log. I'm guessing it was the dhcpcd update.

Checked my pacman.log. You're right, dhcpcd was updated. After reading this thread, I installed dhcpcd 5.0.2 from testing. Still the error message is "greeting" me, when trying to connect to my router via wireless network.

Last edited by mamr (2009-05-11 14:31:27)

rsmarples · 2009-05-12 13:50:37

dhcpcd-4.0.13 upwards requires a serverid option in all DHCP messages.
This is mandated by RFC2131.

Technical - when we renew a lease, we unicast the message to the ServerID (which is the IP address of the DHCP server)

Rational - there are broken DHCP servers commonly found in cheap home routers that NAK even when turned off. These routers don't have a ServerID in the message, so we can safely ignore them

Solution - the DHCP server in your router is faulty - upgrade it

Possible solution - open a ticket at http://roy.marples.name/projects/dhcpcd and ask for NAKs to only look for a ServerID when configured in dhcpcd.conf, which it will do by default if done.

rsmarples · 2009-05-14 00:32:33

rsmarples wrote:

Possible solution - open a ticket at http://roy.marples.name/projects/dhcpcd and ask for NAKs to only look for a ServerID when configured in dhcpcd.conf, which it will do by default if done.

No need for that - I've moved it to a configurable in dhcpcd.conf.
It defaults to requiring ServerID though as it's mandated by RFC2131 AND I have a broken router that NAKs incorrectly and without a serverID.

http://roy.marples.name/projects/dhcpcd … 9c7992022/

dhcpcd-5.0.4 should be out with that over the next few days
Still, you should try and upgrade your router

rsmarples · 2009-05-14 12:03:00

cycyx wrote:

Just joining the thread as I'm no longer able to get an IP address with my OpenBSD 4.3 dhcp server (using the server-identifier directive in conf file).

Is the error the same?
If so, I'd be very interested in seeing a wireshark trace of the transation. If you can get one, email it to roy@marples.name
If not, it's a new bug that will need to be fixed.

So the basic question here is: the serverid may be requested by the RFC, but what to do in order to use DHCP with the current ArchLinux version of dhcpcd?

Not requested, required. Some DHCP message types just won't work without it.
See section 4.3.1 for a nice table of DHCP options which must be present for correct operation to occur.

Thank you for taking care of that issue so quickly, rsmarples.

Not a problem

Assuming you have a compiler, you can try a snapshot from here.

rsmarples · 2009-05-15 07:30:43

dhcpcd-5.0.4 is released with the above change.
Poke the arch dhcpcd maintainer(s) to get it wanged in

scorp · 2009-05-22 12:51:33

Have the same problem here. I have 2 machines connected over WLAN to my router, both running ArchLinux. The one is connected without any problems the other says "ignoring DHCP message; no Server ID". So the router must be OK. I'm using wicd on one machine and netcfg on the other. The second one makes me headaches.

rsmarples · 2009-05-23 08:11:24

Could you email me a wireshark trace of the dhcpcd transaction from the working box and the non working box to the same router please?
I'd be interesting in seeing why one box claimed the serverid was not present.

dhave · 2009-05-23 10:45:26

rsmarples wrote:

dhcpcd-5.0.4 is released with the above change.
Poke the arch dhcpcd maintainer(s) to get it wanged in

So, when I update to dhcpcd-5.0.4, I'll be able to turn this message off? I think it's a completely ignorable message in my case (cheap router), but I'd like to be able to disable it anyway.

I don't think dhcpcd-5.0.4 has appeared in the repos yet, however.

Thanks for your work on this. Dhcpcd is one of the key players in Arch.

rsmarples · 2009-05-23 15:40:35

dhave wrote:

rsmarples wrote:
dhcpcd-5.0.4 is released with the above change.
Poke the arch dhcpcd maintainer(s) to get it wanged in
So, when I update to dhcpcd-5.0.4, I'll be able to turn this message off? I think it's a completely ignorable message in my case (cheap router), but I'd like to be able to disable it anyway.

You can't "turn the message off" as such. You you see the ignoring message then the DHCP packet really is ignored. So if you see that message AND dhcpcd still works with a proper IP (ie not ipv4ll) then you have 2 DHCP servers running on your network and one of them is fautly.

Thanks for your work on this. Dhcpcd is one of the key players in Arch.

No problem

dhave · 2009-05-23 16:23:10

rsmarples wrote:

You can't "turn the message off" as such. You you see the ignoring message then the DHCP packet really is ignored. So if you see that message AND dhcpcd still works with a proper IP (ie not ipv4ll) then you have 2 DHCP servers running on your network and one of them is fautly.

Thanks for the explanation. Is this a problem to have a broken DHCP server running for no purpose? Is this hurting my gas mileage or anything?

rsmarples · 2009-05-23 16:26:54

dhave wrote:

rsmarples wrote:
You can't "turn the message off" as such. You you see the ignoring message then the DHCP packet really is ignored. So if you see that message AND dhcpcd still works with a proper IP (ie not ipv4ll) then you have 2 DHCP servers running on your network and one of them is fautly.
Thanks for the explanation. Is this a problem to have a broken DHCP server running for no purpose? Is this hurting my gas mileage or anything?

Well, you're probably better off finding the faulty router and disabling it.
dhcpcd presently selects and uses the first DHCP working reply it gets and if the server is "fixed" to send ServerID then you could get conflicting lease information.

dhave · 2009-05-23 18:30:09

rsmarples wrote:

dhave wrote:
rsmarples wrote:
You can't "turn the message off" as such. You you see the ignoring message then the DHCP packet really is ignored. So if you see that message AND dhcpcd still works with a proper IP (ie not ipv4ll) then you have 2 DHCP servers running on your network and one of them is fautly.
Thanks for the explanation. Is this a problem to have a broken DHCP server running for no purpose? Is this hurting my gas mileage or anything?
Well, you're probably better off finding the faulty router and disabling it.
dhcpcd presently selects and uses the first DHCP working reply it gets and if the server is "fixed" to send ServerID then you could get conflicting lease information.

I see I have a lot to learn. The reason it's finding two routers is that I have a modem-router and then, in another part of the house, an access point that I've configured as a repeater (actually, since it has a separate ssid, maybe it's not considered a repeater; I don't know).

When I move my laptop from my office into the living room, I often switch from connecting through the "repeater" and connect directly to the modem-router. It's at this point that I get the messages about "no server ID". So, in fact, dhcpcd is doing what it's supposed to be doing, I guess.

I need to do some reading and try to figure out if my setup could be cleaned up so as to avoid lease conflicts or whatever. When I fool with network stuff, I'm always working beyond my level of understanding. I usually just fiddle until I get things to work, which means I probably could do a lot to streamline and improve performance.

Arch Linux

#1 2009-05-11 08:57:36

Wireless: DHCP IP lease attempt failed

#2 2009-05-11 11:08:13

Re: Wireless: DHCP IP lease attempt failed

#3 2009-05-11 12:49:31

Re: Wireless: DHCP IP lease attempt failed

#4 2009-05-11 13:04:43

Re: Wireless: DHCP IP lease attempt failed

#5 2009-05-11 13:32:51

Re: Wireless: DHCP IP lease attempt failed

#6 2009-05-11 14:29:42

Re: Wireless: DHCP IP lease attempt failed

#7 2009-05-12 13:50:37

Re: Wireless: DHCP IP lease attempt failed

#8 2009-05-14 00:32:33

Re: Wireless: DHCP IP lease attempt failed

#9 2009-05-14 12:03:00

Re: Wireless: DHCP IP lease attempt failed

#10 2009-05-15 07:30:43

Re: Wireless: DHCP IP lease attempt failed

#11 2009-05-22 12:51:33

Re: Wireless: DHCP IP lease attempt failed

#12 2009-05-23 08:11:24

Re: Wireless: DHCP IP lease attempt failed

#13 2009-05-23 10:45:26

Re: Wireless: DHCP IP lease attempt failed

#14 2009-05-23 15:40:35

Re: Wireless: DHCP IP lease attempt failed

#15 2009-05-23 16:23:10

Re: Wireless: DHCP IP lease attempt failed

#16 2009-05-23 16:26:54

Re: Wireless: DHCP IP lease attempt failed

#17 2009-05-23 18:30:09

Re: Wireless: DHCP IP lease attempt failed

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