Discussion:
[Dnsmasq-discuss] DHCPV6
Merell Matlock
2018-05-05 23:48:03 UTC
Permalink
Hoping for some help/insight it my attempting to setup IPV6 DHCP; I must
not seem to be able to input the right search terms, because I keep
going around in circles.

My Setup:

ISP <> Modem <> Router <> home network

DNS/DHCP on an RPi3 (DNSMASQ/Pi-hole, behind the router).

V4 DHCP from the RPi works flawlessly.

My router is pulling V6 from the ISP via DHCP-PD, and I can't fine-tune
the routers' RA to only send out route info, and if I disable the RA
from the router, no IPV6 at all (ifconfig/ipconfig only shows link-local
addresses), no matter what I try with DNSMASQ.

IPV6 pass-through on the router has the same result.

Here is what I have from .conf files (all from pi-hole interface):

enable-ra
dhcp-option=option6:dns-server,[::]
dhcp-range=::100,::1ff,constructor:eth0,ra-names,slaac,168h
ra-param=*,high,60,0

I changed the ra-param in an attempt to bypass the routers' RA.

Option6 is working as expected.

Any ideas, or am I just looking at a pipe dream (wanting host names in
the pi-hole query log, instead of IPV6 addresses).

Thank you,


Merell Matlock
M. Buecher
2018-05-06 01:37:30 UTC
Permalink
Hi there,

IPv6 is by definition "multi-homed", so you would do Global Unicast
Addresses (GUA; Prefix 2000::/3; RFC 4291) via your router and Unique
Local Addresses (ULA; Prefix fc00::/7; RFC 4193) via dnsmasq.

If you want to manager GUA also via dnsmasq, then you need to do DHCP-PD
from dnsmasq to your router.

What kind of prefix do you get from your ISP? /48, /56, /60, /64?

Regards
Maddes
Post by Merell Matlock
Hoping for some help/insight it my attempting to setup IPV6 DHCP; I must
not seem to be able to input the right search terms, because I keep
going around in circles.
ISP <> Modem <> Router <> home network
DNS/DHCP on an RPi3 (DNSMASQ/Pi-hole, behind the router).
V4 DHCP from the RPi works flawlessly.
My router is pulling V6 from the ISP via DHCP-PD, and I can't fine-tune
the routers' RA to only send out route info, and if I disable the RA
from the router, no IPV6 at all (ifconfig/ipconfig only shows link-local
addresses), no matter what I try with DNSMASQ.
IPV6 pass-through on the router has the same result.
enable-ra
dhcp-option=option6:dns-server,[::]
dhcp-range=::100,::1ff,constructor:eth0,ra-names,slaac,168h
ra-param=*,high,60,0
I changed the ra-param in an attempt to bypass the routers' RA.
Option6 is working as expected.
Any ideas, or am I just looking at a pipe dream (wanting host names in
the pi-hole query log, instead of IPV6 addresses).
Thank you,
Merell Matlock
_______________________________________________
Dnsmasq-discuss mailing list
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Merell L. Matlock, Jr.
2018-05-07 14:16:01 UTC
Permalink
Interesting reads. I even understood 1/4 of them :)

My router does not (as far as I can tell, digging thru IPV6 settings) do
GUA addressing. I think I understand how to get dnsmasq issue ULA's,
based upon a previous message from you (Sun Aug 20 14:33:35 BST 2017).

Based upon this:

dhcp-range=set:ula6,fd7a:d:e:f::1:0,fd7a:d:e:f::1:ffff,64,12h

Would I then comment out the line from my config:

dhcp-range=::100,::1ff,constructor:eth0,ra-names,slaac,168h

I assume that would give me fc00::/7 addresses for my clients, with
global addresses coming from the router?

I get a /64 from my ISP: (2600:8807:xxxx:27::/64)

Thanks,

Merell
Post by M. Buecher
Hi there,
IPv6 is by definition "multi-homed", so you would do Global Unicast
Addresses (GUA; Prefix 2000::/3; RFC 4291) via your router and Unique
Local Addresses (ULA; Prefix fc00::/7; RFC 4193) via dnsmasq.
If you want to manager GUA also via dnsmasq, then you need to do DHCP-PD
from dnsmasq to your router.
What kind of prefix do you get from your ISP? /48, /56, /60, /64?
Regards
Maddes
 
Post by Merell Matlock
Hoping for some help/insight it my attempting to setup IPV6 DHCP; I must
not seem to be able to input the right search terms, because I keep
going around in circles.
ISP <> Modem <> Router <> home network
DNS/DHCP on an RPi3 (DNSMASQ/Pi-hole, behind the router).
V4 DHCP from the RPi works flawlessly.
My router is pulling V6 from the ISP via DHCP-PD, and I can't fine-tune
the routers' RA to only send out route info, and if I disable the RA
from the router, no IPV6 at all (ifconfig/ipconfig only shows link-local
addresses), no matter what I try with DNSMASQ.
IPV6 pass-through on the router has the same result.
enable-ra
dhcp-option=option6:dns-server,[::]
dhcp-range=::100,::1ff,constructor:eth0,ra-names,slaac,168h
ra-param=*,high,60,0
I changed the ra-param in an attempt to bypass the routers' RA.
Option6 is working as expected.
Any ideas, or am I just looking at a pipe dream (wanting host names in
the pi-hole query log, instead of IPV6 addresses).
Thank you,
Merell Matlock
_______________________________________________
Dnsmasq-discuss mailing list
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Uwe Schindler
2018-05-07 15:16:20 UTC
Permalink
The combination of a range and ra-names can't work. RA is router advertisement and the IP addresses are then given by slaac, so the range must only be a prefix and must have size exactly 64 bits. If you want real DHCP like in ipv4, you must use stateful DHCP, but that won't work with Android phones.
Post by Merell L. Matlock, Jr.
Interesting reads. I even understood 1/4 of them :)
My router does not (as far as I can tell, digging thru IPV6 settings) do
GUA addressing. I think I understand how to get dnsmasq issue ULA's,
based upon a previous message from you (Sun Aug 20 14:33:35 BST 2017).
dhcp-range=set:ula6,fd7a:d:e:f::1:0,fd7a:d:e:f::1:ffff,64,12h
dhcp-range=::100,::1ff,constructor:eth0,ra-names,slaac,168h
I assume that would give me fc00::/7 addresses for my clients, with
global addresses coming from the router?
I get a /64 from my ISP: (2600:8807:xxxx:27::/64)
Thanks,
Merell
Post by M. Buecher
Hi there,
IPv6 is by definition "multi-homed", so you would do Global Unicast
Addresses (GUA; Prefix 2000::/3; RFC 4291) via your router and Unique
Local Addresses (ULA; Prefix fc00::/7; RFC 4193) via dnsmasq.
If you want to manager GUA also via dnsmasq, then you need to do
DHCP-PD
Post by M. Buecher
from dnsmasq to your router.
What kind of prefix do you get from your ISP? /48, /56, /60, /64?
Regards
Maddes
 
Post by Merell Matlock
Hoping for some help/insight it my attempting to setup IPV6 DHCP; I
must
Post by M. Buecher
Post by Merell Matlock
not seem to be able to input the right search terms, because I keep
going around in circles.
ISP <> Modem <> Router <> home network
DNS/DHCP on an RPi3 (DNSMASQ/Pi-hole, behind the router).
V4 DHCP from the RPi works flawlessly.
My router is pulling V6 from the ISP via DHCP-PD, and I can't
fine-tune
Post by M. Buecher
Post by Merell Matlock
the routers' RA to only send out route info, and if I disable the RA
from the router, no IPV6 at all (ifconfig/ipconfig only shows
link-local
Post by M. Buecher
Post by Merell Matlock
addresses), no matter what I try with DNSMASQ.
IPV6 pass-through on the router has the same result.
enable-ra
dhcp-option=option6:dns-server,[::]
dhcp-range=::100,::1ff,constructor:eth0,ra-names,slaac,168h
ra-param=*,high,60,0
I changed the ra-param in an attempt to bypass the routers' RA.
Option6 is working as expected.
Any ideas, or am I just looking at a pipe dream (wanting host names
in
Post by M. Buecher
Post by Merell Matlock
the pi-hole query log, instead of IPV6 addresses).
Thank you,
Merell Matlock
_______________________________________________
Dnsmasq-discuss mailing list
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
_______________________________________________
Dnsmasq-discuss mailing list
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
--
Uwe Schindler
Achterdiek 19, 28357 Bremen
https://www.thetaphi.de

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