[solved] Netctl: ipv4/ipv6 dualstack

triplem · 2014-05-21 20:50:09

I am currently trying to move my network to ipv6. My DSL-Provider already provides me an IPv6 prefix (dynamic that is, unfortunately) and I would like to use this via DHCP. I have two machines in my network which do run nearly 24/7 and both are running ArchLinux and the network is handled by netctl.

Up until now, I have a netctl-profile, which assigns a static IPv4 Adress for each to the specified network device. Now I have added

IP6=dhcp

in the netctl profile, but this brings up an error in the journal

dhclient[5952]: Can't bind to dhcp address: Cannot assign requested address
dhclient[5952]: Please make sure there is no other dhcp server
dhclient[5952]: running and that there's no entry for dhcp or
dhclient[5952]: bootp in /etc/inetd.conf.   Also make sure you
dhclient[5952]: are not running HP JetAdmin software, which
dhclient[5952]: includes a bootp server.

dhclient[5952]: If you think you have received this message due to a bug rather
dhclient[5952]: than a configuration issue please read the section on submitting
dhclient[5952]: bugs on either our web page at www.isc.org or in the README file
dhclient[5952]: before submitting a bug.  These pages explain the proper
dhclient[5952]: process and the information we find helpful for debugging..

dhclient[5952]: exiting.
network[5527]: DHCP IPv6 lease attempt failed on interface 'enp0s25'
network[5527]: Failed to bring the network up for profile 'ethernet-static'
systemd[1]: netctl@ethernet\x2dstatic.service: main process exited, code=exited, status=1/FAILURE
systemd[1]: Failed to start A basic static ethernet connection.
systemd[1]: Unit netctl@ethernet\x2dstatic.service entered failed state.

Thats quite some "red" lines in my journal now ;-( And the network interface does not come up and stays in stated down. Very bad.

To fix this, I have already asked my preferred Search-Engine, but to no avail. I came up with the following netctl profile to avoid this problem:

## for IPv6
#IP6=dhcp
ExecUpPost='dhclient -6 || true'

Unfortunately this does not solve the problem at all, but at least starts the interface and the machine is connected to my LAN.

Any help on this one? Probably I am missing something? Could I handle this whole issue without dhclient?

To be honest, I am pretty new to IPv6, so could be that this is a real NOOB question, but...

Any help is appreciated.

Last edited by triplem (2014-05-23 16:37:27)

train_wreck · 2014-05-22 05:53:00

well actually, i came across a similar problem. ended up using wide-dhcpv6 to do the job, here is my thread about it

https://bbs.archlinux.org/viewtopic.php?id=180414

Last edited by train_wreck (2014-05-22 05:54:01)

triplem · 2014-05-22 19:45:48

Thanks for your reply, but I guess this is more of a router problem. Me is having this issue on a "server".

I just did some more research, and found another dhcp server (using nmap) on my network. This is a DLAN module and I cannot turn off or disable this one, unfortunately. Could be that this one is the problem? Unsure about this one. I just added the IPv4 adress of this thing to the "reject" line of my dhclient.conf. The dhclient.conf looks like

send host-name = pick-first-value(gethostname(), "zeus");
send dhcp-client-identifier 1:0:a0:24:ab:fb:9c;
send dhcp-lease-time 3600;

supersede domain-search "internal.xxxxxx.xxx";

prepend domain-name-servers 127.0.0.1;
request subnet-mask, broadcast-address, time-offset, routers,
        domain-name, domain-name-servers, host-name;
require subnet-mask, domain-name-servers;
timeout 60;
retry 60;
reboot 10;
select-timeout 5;
initial-interval 2;
reject 192.168.xx.xx;

Anyways, starting the netctl profile with only IPv4 and running

dhclient -6 -v

manually afterwards did the trick.

I definitly would like to automate this, though.

Last edited by triplem (2014-05-22 19:55:21)

teekay · 2014-05-23 11:01:39

triplem wrote:

Could I handle this whole issue without dhclient?

If you router supports SLAAC (StateLess Address AutoConfiguration) then: yes.

In the profile:

IP6=stateless

triplem · 2014-05-23 16:36:35

Thanks for the hint ;-)

Works now like a charm. On my Fritz Box 7390 I had to configure IP6 to use Fritz Box as the DHCPv6 server and just assign only the DNS-Server to clients.

Now my server gets the ipv6 prefix from the Fritz Box ;-)

Arch Linux

#1 2014-05-21 20:50:09

[solved] Netctl: ipv4/ipv6 dualstack

#2 2014-05-22 05:53:00

Re: [solved] Netctl: ipv4/ipv6 dualstack

#3 2014-05-22 19:45:48

Re: [solved] Netctl: ipv4/ipv6 dualstack

#4 2014-05-23 11:01:39

Re: [solved] Netctl: ipv4/ipv6 dualstack

#5 2014-05-23 16:36:35

Re: [solved] Netctl: ipv4/ipv6 dualstack

Board footer