Arch Linux

gay

Member

Registered: 2012-12-16

Posts: 93

dhcp server won't admit my Arch Linux (though Win's have no problems)

1. Generally my dhcpcd works fine in every network (and always has, I have not changed anything substantial).
2. Currently I am in a network (for just a couple of weeks) in which it does not.
3. The network will ignore all my dhcp requests over both network devices, enp1s0 and wlp2s0 (ethernet and wifi)
4. When trying the same from Windows (dual boot), the dhcp client works brilliantly (i.e. the hardware is fine)
5. I can force entry into the cable network by simply assigning an IP address and setting netmask and gateway as was configured by dhcp when I tried from Windows
6. For wifi this does not work. More specifically it works for a brief moment if (and only if) I was connected from Windows immediately before and assign myself the same IP address (I can ping the gateway and also 8.8.8.8). After this moment the network apparently kicks me out (cannot ping anything any more, nothing answers). dhcpcd inform (dhcpcd -s <IP Adress>) does not fare better.
7. I tried changing some of the settings in dhcpcd.conf that have been given as reasons for similar problems in the forums, archwiki, or somewhere else, including exchanging 'duid' for 'clientid', and commenting out 'require dhcp_server_identifier'. Does not help. My dhcpcd.conf, see below.
8. dhclient does not work either.

What I want: Connect to the internet via wifi from Arch.

I guess this comes down to making the dhcp server believe my Arch was one of the Windowses it is used to. How do I do that?

I understand that dhcp does not involve clients revealing their operating systems to the servers; but some configurations are likely different between Arch and Windows. I am not used to working with Windows and have no idea how to access the dhcp client configuration settings there (if this is even possible) to get an idea what exactly is different. Here is my dhcpcd.conf - any ideas what exactly about it displeases the server so much or what I might change or add to make the server more pleasantly inclined?

dhcpcd.conf

hostname
clientid
#duid
persistent
option rapid_commit
option domain_name_servers, domain_name, domain_search, host_name 
option classless_static_routes
option ntp_servers
#require dhcp_server_identifier
nohook lookup-hostname
noipv4ll

I would include the logs as well, but they are boring beyond belief, do not contain anything except for dhcpcd trying and failing with timeout.

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We are exactly the people our parents always warned us about.

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,353

Re: dhcp server won't admit my Arch Linux (though Win's have no problems)

Without the boring logs it is hard to tell, but is your system trying to use IPv6? 
Have you tried to disable IPv6?

---

Nothing is too wonderful to be true, if it be consistent with the laws of nature -- Michael Faraday
Sometimes it is the people no one can imagine anything of who do the things no one can imagine. -- Alan Turing
---
How to Ask Questions the Smart Way

gay

Member

Registered: 2012-12-16

Posts: 93

Re: dhcp server won't admit my Arch Linux (though Win's have no problems)

Thanks for the suggestion. Yes, I tried both with and without IPv6 enabled; doesn't make a difference.

Here are the boring logs (first without (dhcpcd -4), then with IPv6 enabled)

$ sudo dhcpcd -d -4 wlp2s0
dhcpcd[875]: version 6.1.0 starting
dhcpcd[875]: wlp2s0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' PREINIT
dhcpcd[875]: wlp2s0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' CARRIER
dhcpcd[875]: wlp2s0: using ClientID <the mac address>
dhcpcd[875]: wlp2s0: soliciting a DHCP lease
dhcpcd[875]: wlp2s0: sending DISCOVER (xid 0x1fed7c51), next in 3.05 seconds
dhcpcd[875]: wlp2s0: sending DISCOVER (xid 0x1fed7c51), next in 8.35 seconds
dhcpcd[875]: wlp2s0: sending DISCOVER (xid 0x1fed7c51), next in 15.68 seconds
dhcpcd[875]: wlp2s0: sending DISCOVER (xid 0x1fed7c51), next in 32.71 seconds
dhcpcd[875]: timed out
dhcpcd[875]: exited
$ sudo dhcpcd -d wlp2s0
dhcpcd[939]: version 6.1.0 starting
dhcpcd[939]: wlp2s0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' PREINIT
dhcpcd[939]: wlp2s0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' CARRIER
dhcpcd[939]: wlp2s0: soliciting an IPv6 router
dhcpcd[939]: wlp2s0: sending Router Solicitation
dhcpcd[939]: wlp2s0: using ClientID 01:<the mac address>
dhcpcd[939]: wlp2s0: soliciting a DHCP lease
dhcpcd[939]: wlp2s0: sending DISCOVER (xid 0xf417f361), next in 4.28 seconds
dhcpcd[939]: wlp2s0: sending Router Solicitation
dhcpcd[939]: wlp2s0: sending DISCOVER (xid 0xf417f361), next in 8.92 seconds
dhcpcd[939]: wlp2s0: sending Router Solicitation
dhcpcd[939]: wlp2s0: sending Router Solicitation
dhcpcd[939]: wlp2s0: no IPv6 Routers available
dhcpcd[939]: wlp2s0: sending DISCOVER (xid 0xf417f361), next in 16.45 seconds
dhcpcd[939]: wlp2s0: sending DISCOVER (xid 0xf417f361), next in 31.59 seconds
dhcpcd[939]: timed out
dhcpcd[939]: exited
$

journal

May 23 21:06:23 <the hostname> sudo[874]: <the user name> : TTY=pts/4 ; PWD=/home/<the user name> ; USER=root ; COMMAND=/usr/bin/dhcpcd -d -4 wlp2s0
May 23 21:06:23 <the hostname> sudo[874]: pam_unix(sudo:session): session opened for user root by <the user name>(uid=0)
May 23 21:06:23 <the hostname> dhcpcd[875]: version 6.1.0 starting
May 23 21:06:23 <the hostname> dhcpcd[875]: wlp2s0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' PREINIT
May 23 21:06:23 <the hostname> dhcpcd[875]: wlp2s0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' CARRIER
May 23 21:06:23 <the hostname> dhcpcd[875]: wlp2s0: using ClientID 01:<the mac address>
May 23 21:06:23 <the hostname> dhcpcd[875]: wlp2s0: soliciting a DHCP lease
May 23 21:06:23 <the hostname> dhcpcd[875]: wlp2s0: sending DISCOVER (xid 0x1fed7c51), next in 3.05 seconds
May 23 21:06:26 <the hostname> dhcpcd[875]: wlp2s0: sending DISCOVER (xid 0x1fed7c51), next in 8.35 seconds
May 23 21:06:34 <the hostname> dhcpcd[875]: wlp2s0: sending DISCOVER (xid 0x1fed7c51), next in 15.68 seconds
May 23 21:06:50 <the hostname> dhcpcd[875]: wlp2s0: sending DISCOVER (xid 0x1fed7c51), next in 32.71 seconds
May 23 21:06:53 <the hostname> dhcpcd[875]: timed out
May 23 21:06:53 <the hostname> dhcpcd[875]: exited
May 23 21:06:53 <the hostname> sudo[874]: pam_unix(sudo:session): session closed for user root
May 23 21:07:01 <the hostname> sudo[938]: <the user name> : TTY=pts/4 ; PWD=/home/<the user name> ; USER=root ; COMMAND=/usr/bin/dhcpcd -d wlp2s0
May 23 21:07:01 <the hostname> sudo[938]: pam_unix(sudo:session): session opened for user root by <the user name>(uid=0)
May 23 21:07:01 <the hostname> dhcpcd[939]: version 6.1.0 starting
May 23 21:07:01 <the hostname> dhcpcd[939]: wlp2s0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' PREINIT
May 23 21:07:01 <the hostname> dhcpcd[939]: wlp2s0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' CARRIER
May 23 21:07:01 <the hostname> dhcpcd[939]: wlp2s0: soliciting an IPv6 router
May 23 21:07:01 <the hostname> dhcpcd[939]: wlp2s0: sending Router Solicitation
May 23 21:07:01 <the hostname> dhcpcd[939]: wlp2s0: using ClientID 01:<the mach address>
May 23 21:07:01 <the hostname> dhcpcd[939]: wlp2s0: soliciting a DHCP lease
May 23 21:07:01 <the hostname> dhcpcd[939]: wlp2s0: sending DISCOVER (xid 0xf417f361), next in 4.28 seconds
May 23 21:07:05 <the hostname> dhcpcd[939]: wlp2s0: sending Router Solicitation
May 23 21:07:05 <the hostname> dhcpcd[939]: wlp2s0: sending DISCOVER (xid 0xf417f361), next in 8.92 seconds
May 23 21:07:09 <the hostname> dhcpcd[939]: wlp2s0: sending Router Solicitation
May 23 21:07:13 <the hostname> dhcpcd[939]: wlp2s0: sending Router Solicitation
May 23 21:07:13 <the hostname> dhcpcd[939]: wlp2s0: no IPv6 Routers available
May 23 21:07:14 <the hostname> dhcpcd[939]: wlp2s0: sending DISCOVER (xid 0xf417f361), next in 16.45 seconds
May 23 21:07:31 <the hostname> dhcpcd[939]: wlp2s0: sending DISCOVER (xid 0xf417f361), next in 31.59 seconds
May 23 21:07:31 <the hostname> dhcpcd[939]: timed out
May 23 21:07:31 <the hostname> dhcpcd[939]: exited

the only thing I find mildly odd ybout the logs is that in the "using ClientId" a 01: preceeds the mac address (I double checked, the 01 is not part of my mac address). The corresponding code apparently is like in lines 822-23 here, https://android.googlesource.com/platfo … e/dhcpcd.c

syslog(LOG_DEBUG, "%s: using hwaddr %s", iface->name,
hwaddr_ntoa(iface->hwaddr, iface->hwlen));

where I don't see where the additional 01 would come from. But anyway, this is kind of unlikely to be related to the problem.

dmesg has nothing at all to say about this. is there any place else where there might be any logs? the dhcp server logs would certainly be very enlightening, unfortunately I don't have access.

Last edited by gay (2014-05-23 17:24:49)

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We are exactly the people our parents always warned us about.

MoonSwan

Member

From: Great White North

Registered: 2008-01-23

Posts: 881

Re: dhcp server won't admit my Arch Linux (though Win's have no problems)

I am not used to working with Windows and have no idea how to access the dhcp client configuration settings there (if this is even possible) to get an idea what exactly is different. Here is my dhcpcd.conf - any ideas what exactly about it displeases the server so much or what I might change or add to make the server more pleasantly inclined?

To get to Windows' IP address and network settings navigate to:  Control Panel -> Network and Internet -> Network Connections -> Click on Device Here (WIFI or LAN) -> Properties and from there you should be able to see the settings you need to figure out what's going on in Windows.

Btw, love the name, it's nice to see such a name after seeing so many that are intentionally hurtful to others of any stripe in a rainbow. 

Last edited by MoonSwan (2014-05-23 17:31:54)

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,353

Re: dhcp server won't admit my Arch Linux (though Win's have no problems)

Interesting.  Generally I have seen problems where one end or the other refuses an address.  From those logs, it appears there are no servers that even respond to a solicitation.  I guess it could be a MAC problem. but I don't know.  Can you get to the router logs? Can you see if the router saw a solicitation?

Also, (just a sanity check) are you sure you are connected to the correct access point?  But that does not make sense -- you said this happens on wired as well  
Dang.   

Is this a corporate environment? A school perhaps?

---

Nothing is too wonderful to be true, if it be consistent with the laws of nature -- Michael Faraday
Sometimes it is the people no one can imagine anything of who do the things no one can imagine. -- Alan Turing
---
How to Ask Questions the Smart Way

gay

Member

Registered: 2012-12-16

Posts: 93

Re: dhcp server won't admit my Arch Linux (though Win's have no problems)

Thanks, MoonSwan & ewaller,

Windows' IP address and network settings navigate to:  Control Panel -> Network and Internet -> Network Connections -> Click on Device Here (WIFI or LAN) -> Properties and from there you should be able to see the settings you need to figure out what's going on in Windows.

Found that, There are a lot of "Advanced properties", for instance "Bandwidth Capacity" is set to "11b/g: 20MHz", "BSS Mode" is set to "802.11n Mode", "Fragmentation Threshold" to "2346" (whatever that may mean) ... etc. Unfortunately, I cant copy any of that; most of it also seems rather unimportant; also I left all this on its default setting when I followed the instructions on how to connect to this wifi on Windows.

However, here is some information I managed to squeeze out of the pathetic, pittyful Windows terminal which they call the "Comand Line"

C:\Windows\system32> ipconfig /all 

<...>

Wireless LAN adapter Wireless Network Connection:

   Connection-specific DNS Suffix  . : <the network name>
   Description . . . . . . . . . . . : <hardware description> 802.11b/g/n (2.4GHz)
   Physical Address. . . . . . . . . : <the mac address>
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : <some ipv6> %13(Preferred)
   IPv4 Address. . . . . . . . . . . : <the ipv4> (Preferred)
   Subnet Mask . . . . . . . . . . . : <subnet mask>
   Lease Obtained. . . . . . . . . . : Fri, 23. May 2014 19:47:10
   Lease Expires . . . . . . . . . . : Fri, 23. May 2014 21:17:09
   Default Gateway . . . . . . . . . : <gateway ip>
   DHCP Server . . . . . . . . . . . : <some ip that is not part of the local subnet>
   DHCPv6 IAID . . . . . . . . . . . : 319352249
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-18-9F-0F-D6-E0-DB-55-CF-26-6

   DNS Servers . . . . . . . . . . . : <a few dns server ip's>
   NetBIOS over Tcpip. . . . . . . . : Enabled


Tunnel adapter Teredo Tunneling Pseudo-Interface:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : <some ipv6> (Preferred)
   Link-local IPv6 Address . . . . . : <another ipv6> %12(Preferred)
   Default Gateway . . . . . . . . . :
   NetBIOS over Tcpip. . . . . . . . : Disabled


Tunnel adapter 6TO4 Adapter:

   Connection-specific DNS Suffix  . : <the network name>
   Description . . . . . . . . . . . : Microsoft 6to4 Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : <some ipv6> (Preferred)
   Default Gateway . . . . . . . . . : <another ipv6>
                                       <yet another ipv6>
   DNS Servers . . . . . . . . . . . : <the same ipv4 dns server ip's as above>     
   NetBIOS over Tcpip. . . . . . . . : Disabled


C:\Windows\system32> netsh wlan show all

Wireless System Information Summary
(Time: 23.05.2014 20:38:49 W. Europe Daylight Time)


=======================================================================
============================== SHOW DRIVERS ===========================
=======================================================================


Interface name: Wireless Network Connection

    Driver                    : <hardware description> 802.11b/g/n (2.4GHz)
    Vendor                    : Broadcom
    Provider                  : Broadcom
    Date                      : 21.01.2012
    Version                   : 6.20.55.31
    INF file                  : C:\Windows\INF\oem25.inf
    Files                     : 5 total
                                C:\Windows\system32\DRIVERS\BCMWL664.SYS
                                C:\Windows\system32\bcmihvsrv64.dll
                                C:\Windows\system32\bcmihvui64.dll
                                C:\Windows\system32\drivers\vwifibus.sys
                                C:\Windows\system32\bcmwlcoi.dll
    Type                      : Native Wi-Fi Driver
    Radio types supported     : 802.11n 802.11g 802.11b
    FIPS 140-2 mode supported : Yes
    Hosted network supported  : Yes
    Authentication and cipher supported in infrastructure mode:
                                Open            None
                                Open            WEP
                                Shared          None
                                Shared          WEP
                                WPA2-Enterprise TKIP
                                WPA2-Personal   TKIP
                                WPA2-Enterprise CCMP
                                WPA2-Personal   CCMP
                                WPA2-Enterprise Vendor defined
                                WPA2-Enterprise Vendor defined
                                Vendor defined  Vendor defined
                                Vendor defined  Vendor defined
                                Vendor defined  TKIP
                                Vendor defined  CCMP
                                Vendor defined  Vendor defined
                                Vendor defined  Vendor defined
                                WPA-Enterprise  TKIP
                                WPA-Personal    TKIP
                                WPA-Enterprise  CCMP
                                WPA-Personal    CCMP
    Authentication and cipher supported in ad-hoc mode:
                                WPA2-Personal   CCMP
                                Open            None
                                Open            WEP
    IHV service present       : Yes
    IHV adapter OUI           : [00 10 18], type: [00]
    IHV extensibility DLL path: C:\Windows\System32\bcmihvsrv64.dll
    IHV UI extensibility ClSID: {aaa6dee9-31b9-4f18-ab39-82ef9b06eb73}
    IHV diagnostics CLSID     : {00000000-0000-0000-0000-000000000000}


=======================================================================
============================= SHOW INTERFACES =========================
=======================================================================


There is 1 interface on the system:

    Name                   : Wireless Network Connection
    Description            :  802.11b/g/n (2.4GHz)
    GUID                   : 6d122ca5-cdc2-42d1-a1fb-3754098b19eb
    Physical address       : <the mac address>
    State                  : connected
    SSID                   : <ssid>
    BSSID                  : <access point mac address>
    Network type           : Infrastructure
    Radio type             : 802.11n
    Authentication         : WPA2-Enterprise
    Cipher                 : CCMP
    Connection mode        : Auto Connect
    Channel                : 1
    Receive rate (Mbps)    : 72
    Transmit rate (Mbps)   : 72
    Signal                 : 83%
    Profile                : <ssid>

    Hosted network status  : Not available


=======================================================================
=========================== SHOW HOSTED NETWORK =======================
=======================================================================


Hosted network settings
-----------------------
    Mode                   : Disallowed
    Settings               : <Not configured>

Hosted network status
---------------------
    Status                 : Not available


=======================================================================
============================= SHOW SETTINGS ===========================
=======================================================================


Wireless LAN settings
---------------------
    Show blocked networks in visible network list: No

    Only use GP profiles on GP-configured networks: No

    Hosted network mode allowed in WLAN service: No

    Allow shared user credentials for network authentication: Yes

    Block period: Not Configured.

    Auto configuration logic is enabled on interface "Wireless Network Connection"


=======================================================================
============================== SHOW FILTERS ===========================
=======================================================================


Allow list on the system (group policy)
---------------------------------------
    <None>

Allow list on the system (user)
-------------------------------
    <None>

Block list on the system (group policy)
---------------------------------------
    <None>

Block list on the system (user)
-------------------------------
    <None>


=======================================================================
=========================== SHOW CREATEALLUSER ========================
=======================================================================


Everyone is allowed to create all user profiles.


=======================================================================
============================= SHOW PROFILES ===========================
=======================================================================


Profiles on interface Wireless Network Connection:

Group policy profiles (read only)
---------------------------------
    <None>

User profiles
-------------
    All User Profile     : <ssid>
			<other profile names>

=======================================================================
========================== SHOW PROFILES NAME=* =======================
=======================================================================


Profile eduroam on interface Wireless Network Connection:
=======================================================================

Applied: All User Profile

Profile information
-------------------
    Version                : 1
    Type                   : Wireless LAN
    Name                   : <ssid>
    Control options        :
        Connection mode    : Connect automatically
        Network broadcast  : Connect only if this network is broadcasting
        AutoSwitch         : Do not switch to other networks

Connectivity settings
---------------------
    Number of SSIDs        : 1
    SSID name              : "<ssid>"
    Network type           : Infrastructure
    Radio type             : [ Any Radio Type ]
    Vendor extension          : Not present

Security settings
-----------------
    Authentication         : WPA2-Enterprise
    Cipher                 : CCMP
    Security key           : Absent
    802.1X                 : Enabled
    EAP type               : Microsoft: Protected EAP (PEAP)
    802.1X auth credential : Machine or user credential
    Cache user information : Yes


<other profiles ...>

=======================================================================
======================= SHOW NETWORKS MODE=BSSID ======================
=======================================================================


Interface name : Wireless Network Connection
There are 4 networks currently visible.

SSID 1 : eduroam
    Network type            : Infrastructure
    Authentication          : WPA2-Enterprise
    Encryption              : CCMP
    BSSID 1                 : <other access point ssid>
         Signal             : 2%
         Radio type         : 802.11n
         Channel            : 11
         Basic rates (Mbps) : 1 2 5.5 11
         Other rates (Mbps) : 6 9 12 18 24 36 48 54
    BSSID 2                 : <other access point ssid>
         Signal             : 0%
         Radio type         : 802.11n
         Channel            : 11
         Basic rates (Mbps) : 1 2 5.5 11
         Other rates (Mbps) : 6 9 12 18 24 36 48 54
    BSSID 3                 : <access point ssid>
         Signal             : 87%
         Radio type         : 802.11n
         Channel            : 1
         Basic rates (Mbps) : 1 2 5.5 11
         Other rates (Mbps) : 6 9 12 18 24 36 48 54
    BSSID 4                 : <other access point ssid>
         Signal             : 0%
         Radio type         : 802.11n
         Channel            : 1
         Basic rates (Mbps) : 1 2 5.5 11
         Other rates (Mbps) : 6 9 12 18 24 36 48 54

SSID 2 : <...>

What I find odd is this "Taredo Tunneling Pseudo-Interface". As a matter of fact, I have not the slightest idea if this is happening inside this local Windows I have here or if this is something real in the network configuration (on the other side of the access point)... It apparently should tunnel IPv6 to IPv4 and/or vice versa. However, why would there be two connections over the same network interface (IPv6 and IPv4)...

What is odd as well is that the DHCP server is not part of the subnet my Windows is in. It just seems to announce IP, netmask, gateway to the Windows ... (the gateway is in the subnet). Could it be that the Linux dhcp client does not accept something like that. No, that's unlikely, right? dhcpcd -d should have reported this...

Btw, love the name,

Thanks. Likewise

it's nice to see such a name after seeing so many that are intentionally hurtful to others of any stripe in a rainbow.

Actually, I always felt that the Arch Forum is quite tolerant in this respect. (And so is reddit, but of course, you are right, there are places on the internet where you can run into a lot of assholes. Kind of like in the real world... Quite frustrating.)

I guess it could be a MAC problem. but I don't know.

Unlikely; on windows the mac address is the same.

  Can you get to the router logs? Can you see if the router saw a solicitation?

no. and given their network configuration I don't suppose the IT people here would be very forthcoming if I asked them. Their helpdesk said that they couldn't help me since my laptop was not one of their computers.

Also, (just a sanity check) are you sure you are connected to the correct access point?  But that does not make sense -- you said this happens on wired as well sad
Dang.

I am. It's WPA2 encrypted & I only have access data to this one wifi network. (To avoid confusing everyone with mentioning too many different things, I did not detail this in the original post. I am accessing it using wpa_supplicant running in a terminal; wpa_supplicant works fine says "connection succeeded" etc. So the problem is not in the WPA/ wifi-connection layer but really in the IP/dhcp layer.)

Is this a corporate environment? A school perhaps?

Yes, a university. They have someone working here who went through great lengths to make it difficult for people to connect to the internet.

---

We are exactly the people our parents always warned us about.

gay

Member

Registered: 2012-12-16

Posts: 93

Re: dhcp server won't admit my Arch Linux (though Win's have no problems)

Problem persists. Today I realized that while most of the time I am getting no response to dhcpcd requests from Arch on wifi, I occasionally receive a dhcp offer; however, the negotiation is not successfully completed. Occasionally means maybe 1 in 30 times (maybe also only at specific times, when it suits the server to talk to me; maybe also only the first time after I didn't try it for some time; maybe I'm getting somehow blacklisted).

What the server says - in these rare instances - is:

$ sudo dhcpcd -T wlp2s0
dhcpcd[5487]: version 6.1.0 starting
dhcpcd[5487]: wlp2s0: waiting for carrier
dhcpcd[5487]: wlp2s0: carrier acquired
dhcpcd[5487]: wlp2s0: soliciting an IPv6 router
dhcpcd[5487]: wlp2s0: soliciting a DHCP lease
dhcpcd[5487]: wlp2s0: offered XXX.XX.106.184 from 172.20.1.1
interface=wlp2s0
pid=5487
reason=TEST
skip_hooks=lookup-hostname
new_broadcast_address=XXX.XX.107.255
new_dhcp_lease_time=3600
new_dhcp_message_type=2
new_dhcp_rebinding_time=3150
new_dhcp_renewal_time=1800
new_dhcp_server_identifier=172.20.1.1
new_domain_name=<subdomain>.<domain>
new_domain_name_servers='XXX.XX.6.111 XXX.XX.6.112'
new_domain_search='<subdomain>.<domain> <further subdomain>.<domain> <further subdomain>.<domain> <further subdomain>.<domain> <domain>'
new_ip_address=XXX.XX.106.184
new_network_number=XXX.XX.104.0
new_ntp_servers=XXX.XX.8.22
new_routers=XXX.XX.104.1
new_subnet_cidr=22
new_subnet_mask=255.255.252.0
dhcpcd[5487]: exited
$

Note that the dhcp server is not talking from the same subnet for which it administers addresses but from the 172.16\12 class B private IP range. Isn't this odd?

Also is it possibly that my arch does somehow not behave as the server would like it to and the server gets angry about that? ... thus refusing to acknowledge the successful negotiation of a dhcp lease ... and maybe blacklisting the mac? In that case - what do I do to solve this?

On a sidenote: I also tried pump from AUR (as an alternative to dhcpcd and dhclient) in the meantime; no luck.

Any thoughts or ideas on this? Thanks ...

Last edited by gay (2014-05-26 15:41:51)

---

We are exactly the people our parents always warned us about.

gay

Member

Registered: 2012-12-16

Posts: 93

Re: dhcp server won't admit my Arch Linux (though Win's have no problems)

strangely dhclient works perfectly well for debian (booting the same machine from usb)

DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 6
DHCPREQUEST on eth1 to 255.255.255.255 port 67
DHCPOFFER from 172.20.1.1
DHCPACK from 172.20.1.1
bound to XX.XX.107.35 -- renewal in 1523 seconds.

the live debian's dhclient.conf is

option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;
send host-name = gethostname();
request subnet-mask, broadcast-address, time-offset, routers,
domain-name, domain-name-servers, domain-search, host-name,
dhcp6.name-servers, dhcp6.domain-search,
netbios-name-servers, netbios-scope, interface-mtu,
rfc3442-classless-static-routes, ntp-servers;
option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;
option ms-classless-static-routes code 249 = array of unsigned integer 8;
option wpad code 252 = string;

also request rfc3442-classless-static-routes;
also request ms-classless-static-routes;
also request wpad;
also request ntp-servers;

if that conf file somehow does the job as well on arch, we can mark the issue solved ... i'll only be able to test that next week

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We are exactly the people our parents always warned us about.

gay

Member

Registered: 2012-12-16

Posts: 93

Re: dhcp server won't admit my Arch Linux (though Win's have no problems)

Interestingly, now dhcp over ethernet works also with arch (with the dhclient.conf above); dhcp over wifi (and indeed any connection over wifi) does still not work from Arch (even with the dhclient.conf above).

I have no idea what is going on.

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We are exactly the people our parents always warned us about.

gay

Member

Registered: 2012-12-16

Posts: 93

Re: dhcp server won't admit my Arch Linux (though Win's have no problems)

Sorry for necrobumping this. The problem still persists and I happened to be logged into the forum again after a long time and wanted to let you know what little progress I made on this issue during the last year.

Regarding the ethernet, I found that the standard network configuration on Arch seems to be a little picky about to whom it talks. In some networks this causes problems immediately (particularly if the dhcp server advertises a subnet which it is not even part of), sometimes only after awakening from suspend. This is sometimes (not always) solved by putting the ethernet device into promiscuous mode, e.g.

sudo ifconfig enp1s0 promisc

I don't know if there are any downsides to this, but I'm sure there was a reason for making the default configuration more cautious than on other systems.

As for the wifi, I believe that part of the problem is the proprietary Broadcom device and driver - sometimes, strange errors related to this appear in dmesg. I have given up trying to make the wifi behave and am hoping that some time there might be a better and non-proprietary driver.

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We are exactly the people our parents always warned us about.