IPv6 DHCP [SOLVED]

diemuzi · 2012-04-13 15:07:11

I've been running an IPv6 "Static" network for some time now without any troubles and all seems to be working quite well however now I'm looking to create a DHCPv6 network while using netcfg. Initial testing works, I am receiving a IPv6 address as expected. But what I cannot figure out is how can I make sure a specific interface "eth0" receives a certain IPv6 IP Address. On my Windows machine I found my Client ID and was able to set the host-identifier option dhcp6.client-id and I receive the IP I desired to use. However on my testing server which runs the latest build of Archlinux I cannot seem to make the server receive the IP I want.

I've tried both dhcpcd and dhclient but so far no luck. I always receive an IP, just not the one I want as defined by the DHCPv6 server.

Any help would be great! I'm open to any suggestions to try out and can supply any amount of details you may want to know as well.

Thank you!

Last edited by diemuzi (2012-04-16 13:28:45)

Strike0 · 2012-04-13 17:39:56

I don't quite understand how you set a static IPv6 so far, but believe the answer you seek is in the ipv6 wiki, not the netcfg one.

diemuzi · 2012-04-13 17:46:51

I already mentioned that my IPv6 network is working so the IPv6 wiki is used up at this point.

As for your comment (netcfg):
IP6=static
ADDR6=(fd35:4776:6804:2:1::C/128)
ROUTES6=(fd35:4776:6804:2::/64)
GATEWAY6=fd35:4776:6804::1

Now I simply want to use IP6=dhcp and assign IPv6 addresses from my pool but choose which interface gets which IP. Currently I cannot get any clientid/duid to send properly to my DHCPv6 server and return the fixed ipaddress I have setup

Strike0 · 2012-04-13 18:32:02

Ok, so I suppose

dhcpcd -D

creates you the DUID, but the soliciting does not work?
Which dhclient options have you tried on the commandline?

diemuzi · 2012-04-13 18:42:46

Looks like I got it working. I must admit that I was going off of information back when IPv6 and DHCPv6 first came out.

So it was my impression that in my DHCP server configuration I had to use the old style of:
host-identifier option dhcp6.client-id 00:01:00:01:17:0B:B9:14:00:1D:60:B7:5F:D4;
fixed-address6 FD35:4776:6804:1::1;

Turns out there is now compatibility with the IPv4 style of setting fixed ip addresses where a clientid / duid isn't required and I was able to set it up as:
hardware ethernet 00:0C:29:37:12:85;
fixed-address6 FD35:4776:6804:2:1::1;

I remember trying the previous a long time ago when hardware ethernet wasn't allowed to be used with IPv6 but it appears that has now changed.

All is well now and things are finally back on track.

Gcool · 2012-04-13 21:03:13

Hardware ethernet is indeed the most straighforward way to do it now (has been like that for a few years afaik). However, I was under the impression that DUID was also still possible/supported. It has been a while since I've had to work with dhcpv6, so don't shoot me if I'm wrong on that last statement.

PS: don't forget to mark your thread as [SOLVED].

fukawi2 · 2012-04-13 23:47:16

diemuzi wrote:

Turns out there is now compatibility with the IPv4 style of setting fixed ip addresses where a clientid / duid isn't required and I was able to set it up as:
hardware ethernet 00:0C:29:37:12:85;
fixed-address6 FD35:4776:6804:2:1::1;

OOooooohhhh, finally
Some of the design decisions that were initially made around IPv6 were just plain stupid IMHO.

Do you remember where you found this information? Which version of DHCPD was this introduced with? It would make my life sooo much easier at work.

Now if they can get a single instance of DHCPD to handle IPv4 and IPv6 leases instead of duplicating processes and config files, I'll be a very happy nerd!

diemuzi · 2012-04-16 13:28:13

@ fukawi2

I'm not exactly certain when IPv6 was finally able to use the hardware ethernet but I can tell you I am using version 4.2.3.2-2 (latest at the time of writing this) and it's working out great! I found the information in a random post online someplace and noticed someone else was using it with an IPv6 address and just decided to give it a try and sure enough it worked.

As for your dual-stack DHCP4 and 6 network, that is something I can help you out with because I am also running a network just like that without problems

The latest version actually comes with two rc.d scripts called dhcp4 and dhcp6. So all I did was create two DHCP scripts named dhcpd.conf.ipv4 and dhcpd.conf.ipv6 and then edited the dhcp4 and dhcp6 scripts to look for those config files

Edit your /etc/rc.d/dhcp4 and look for
if /usr/sbin/dhcpd -4 -pf "$PIDFILE" $DHCP4_ARGS; then

Change it look like this:
if /usr/sbin/dhcpd -4 -cf /etc/dhcpd.conf.ipv4 -pf "$PIDFILE" $DHCP4_ARGS; then

Do the same for the dhcp6 script as well. This will get you up and running without problems

If you want my dhcpd.conf.ipv4 / 6 config files I'd be happy to share those with you as well if it helps.

I hope someday they'll combine them but for now this works out great.

Last edited by diemuzi (2012-04-16 15:38:17)

fukawi2 · 2012-04-17 00:04:07

diemuzi wrote:

I'm not exactly certain when IPv6 was finally able to use the hardware ethernet but I can tell you I am using version 4.2.3.2-2 (latest at the time of writing this) and it's working out great! I found the information in a random post online someplace and noticed someone else was using it with an IPv6 address and just decided to give it a try and sure enough it worked.

Thanks, I'll have to look into it more.... I might have to move my DHCP servers over to an Arch box instead of on my CentOS gateways....

diemuzi wrote:

The latest version actually comes with two rc.d scripts called dhcp4 and dhcp6. So all I did was create two DHCP scripts named dhcpd.conf.ipv4 and dhcpd.conf.ipv6 and then edited the dhcp4 and dhcp6 scripts to look for those config files

I'm running a pair of CentOS 6 boxes as an Active/Backup pair; CentOS comes with that setup already (well, different file names, but same concept) which is what I'm using. It works, but it makes me feel dirty.

diemuzi wrote:

I hope someday they'll combine them but for now this works out great.

It would be lovely to be able to define hosts in a single place....

host svr-app-tux1	{ hardware ethernet 00:12:79:3A:96:A5; fixed-address 172.16.0.140; fixed-address6 2001:44B8:xxxx:xxxx:172:16:0:140; }

Last edited by fukawi2 (2012-04-17 00:04:54)

Arch Linux

#1 2012-04-13 15:07:11

IPv6 DHCP [SOLVED]

#2 2012-04-13 17:39:56

Re: IPv6 DHCP [SOLVED]

#3 2012-04-13 17:46:51

Re: IPv6 DHCP [SOLVED]

#4 2012-04-13 18:32:02

Re: IPv6 DHCP [SOLVED]

#5 2012-04-13 18:42:46

Re: IPv6 DHCP [SOLVED]

#6 2012-04-13 21:03:13

Re: IPv6 DHCP [SOLVED]

#7 2012-04-13 23:47:16

Re: IPv6 DHCP [SOLVED]

#8 2012-04-16 13:28:13

Re: IPv6 DHCP [SOLVED]

#9 2012-04-17 00:04:07

Re: IPv6 DHCP [SOLVED]

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