Currently there is no way to specify IPv6 DNS server which DHCP auto-assigns to adapter

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Assuming IPv6 tunnel is already set up and working in the router, try to set 
IPv6 DNS server in the DHCP "DNS Server 1" field.

What is the expected output? 
I want to see that IPv6 DNS server I set in the Win7 ipconfig /all output for 
given adapter or in the resolv.conf (for FreeBSD).

What do you see instead?
I got warning about wrong IP address format, this field expects IPv4 address 
only and refuse to set IPv6 address.

What version of the product are you using?
RT-N-1.9.2.7-rtn-r4330

Please provide any additional information below.
While Win7 see absolutely no auto-assigned IPv6 DNS servers (only IPv4 ones), 
strangely, FreeBSD dhclient is able somehow to fetch IPv6 DNS server from the 
router. But this is IPv6 DNS server specified in the IPv6 tunnel setup page and 
I want to see local router fe80:: address as auto-assigned IPv6 DNS server 
instead. Of course, I can manually specify router's fe80:: address directly in 
the Win7 adapter IPv6 DNS settings (or in the resolv.conf for FreeBSD), but 
this is no way to go for portable device which change nets often.

Original issue reported on code.google.com by ache...@gmail.com on 9 Aug 2012 at 9:03

[GoogleCodeExporter]

there's a manual way with help of dnsmasq:
1. turn off router advert in web ui
2. add following to /usr/local/etc/dnsmasq.conf
dhcp-range=lan,[your-ipv6-lan-prefix],ra-stateless,ra-names
dhcp-option=lan,option6:23,[::],[any-ipv6-dns-server1],[any-ipv6-dns-server2]
enable-ra
3. flashfs save && flashfs commit && flashfs enable && reboot

after that dnsmasq will do SLAAC and announce DNSv6 servers vis DHCPv6

Original comment by themiron.ru on 28 Aug 2012 at 9:16

• Changed state: Accepted

[GoogleCodeExporter]

What do you mean exactly by
1. turn off router advert in web ui
Is it "Enable DHCP server"?
I run full dual-stack network and need both dhcp and dhcpv6 enabled.
Thanks for your tips in any case, I'll look at the dnsmasq manual.
Inspecting sitiation at this moment shows that FreeBSD fetch IPv6 tunnel DNS 
from the router via SLAAC. It is working thing, but always goes through the 
tunnel without any caching on router side. What I want is to assign routers 
IPv6 which not always goes through the tunnels because does caching via dnsmasq.

Original comment by ache...@gmail.com on 28 Aug 2012 at 10:28

[GoogleCodeExporter]

> What do you mean exactly by
> 1. turn off router advert in web ui

Advertise LAN Prefix? No

Original comment by themiron.ru on 6 Sep 2012 at 11:13

[GoogleCodeExporter]

fixed with r4645, LAN IPv6 and any additional DNSv6 will be advertised via 
DHCPv6

Original comment by themiron.ru on 30 Sep 2012 at 5:45

• Changed state: Fixed

[GoogleCodeExporter]

Thanx, situation is a bit better, but still not good.
r4645 now correctly announce router's IPv6 address as IPv6 DNS, but 
additionally still continue to announce tunnel's IPv6 DNS as r4330 does (i.e. I 
have two IPv6 auto-assigned DNSes as result).
Their order is not good, because tunnel's IPv6 DNS always comes first, so all 
Win7 resolving goes slowly through the tunnel and never hits the second IPv6 
DNS (router with the DNS cache).
Perhaps it is the bug or lack of fine-tuning ability of IPv6 DNSes in the 
router.
So, the question: is there a way to disable tunnel's IPv6 DNS announcement in 
the router? I know how to overwrite IPv6 DNS in Win7 and FreeBSD but also I 
have some number of hardware which does not allows any DNS manipulations.

Original comment by ache...@gmail.com on 1 Oct 2012 at 11:22