IPV6 only network

RouterOS General
1

Hi there
I have been running Dual stack for a while and I wanted to cut ipv4 part of the internet and try it on ipv6 only
my ISP uses PPPoE so I am getting /56 prefix which I distribute to my local network

to set this up as dual stack I had to

/ipv6 dhcp-client add add-default-route=yes interface=pppoe-isp pool-name=isp-pd  use-peer-dns=yes pool-prefix-length=64 request=prefix #Request IPV6 prefix and assign it into its pool
/ipv6 firewall filter add action=accept chain=input comment=”DHCPv6 from provider” dst-port=546 in-interface=pppoe-isp protocol=udp #Added a firewall rule that I do not know its meaning :)
/ipv6 address add address=::1/64 from-pool=isp-pd interface=lan advertise=yes #Added my adress pool to my LAN so computers now get its own IP adress from the prefix

and dual stack works now

but if I disable NAT and turn off DHCP server for my ipv6 computers only get IPV6 adress and Windows 7 reports NO internet in ipv4 section which is good, but nothing works, even ping google.com doesn’t which it should since it is hosted on ipv6 adress

so I suspect its DNS problem, but my provider doesn’t have ipv6 DNS servers and I didn’t see any DNS section in ipv6 tab in winbox, so how do I even configure DNS for ipv6 only network on ipv4 you just add DNS Servers in DHCP Server Networks tab

Thanks for Anwsering and Best Regards

2

If you google for google ipv6 dns



Google Public DNS IP addresses
The Google Public DNS IP addresses (IPv4) are as follows:

8.8.8.8
8.8.4.4
The Google Public DNS IPv6 addresses are as follows:

2001:4860:4860::8888
2001:4860:4860::8844
You can use either address as your primary or secondary DNS server.

3

IP → DNS is used both for ipv4 and ipv6: just add ipv6 dns address there and remove all ipv4 ones.

4

but I already have some dynamic DNS servers in ip->DNS
2a00:ee0:d::13
2a00:ee0:d::23

so DNS should work

5

Try to add ones that definitely work, from google (already posted by @romihg) or cloudflare:
2606:4700:4700::1111
2606:4700:4700::1001

6

nope

maybe its a problem because I am using PPPoE to get ipv4,6 adress and I cannot seem to disable getting ipv4 one

BTW: how do computers get ipv6 adresses anyways since DHCPv6 server is blank in winbox? if no DHCP → no ipadress?

7

Windows cannot get DNS server address from IPv6 RA so you need to run a DHCPv6 server for that.
You need to set a fixed option 23 with the IPv6 address(es) you want your clients to use as a 0x11112222333344445555666677778888 hex value corresponding to the DNS server address.
(can be your own router or some external DNS resolver)

8

can I use mikrotiks dhcp6-server for that
if yes How can I set it up since it has no nice setup wizard like ipv4 dhcp sever

BTW: Why use RA if there is dhcp is RA better? or is it only used on dual stack?

9

Using SLAAC

10

The DHCPv6 server on MikroTIk cannot assign IP addresses to the clients.
So you need a hybrid setup where you enable Advertise on the IPv6 address on your LAN (to use RA/SLAAC to assign the address and default route)
and then Linux/Android/Apple devices will get the DNS from that as well (when you Advertise DNS in IPv6->ND), however Windows cannot do that
and it will get the DNS address from DHCPv6.

11

hmm then external DHCP it is something like this: https://www.weird-solutions.com/carrier-solutions/dhcp-broadband
but its expensive but its good like Simple DNS Plus which I am using as my main DNS Server

BTW: How do I specify in RA/SLAAC(Advertise DNS) that I want to use some other DNS Server not mikrotiks?
in ND there is also 6to4 tab not sure but no DNS Server tab where I could specify DNSs IP to advertise

12

This is indicated by the “managed address configuration” option in the ND settings.
That indicates to the RA listeners that they should use DHCPv6 instead of SLAAC.
However, that is not a usual configuration for IPv6 and you may encounter devices that do not support it.

13

Few notes:

  • Newer versions of Windows 10 can get DNS from RA (it came out about a year ago, I guess)
  • RA in RouterOS takes DNS addresses only from IP->DNS and currently you can’t do anything about it
  • DHCPv6 does the same, but you can override it with manually created option
  • You need ‘other configuration’ option enabled in IP->ND, to tell clients to ask DHCPv6
  • You must not enable ‘managed address configuration’, because that tells clients to use DHCPv6 to get addresses and RouterOS doesn’t support that
  • Older Windows have hardcoded DNS resolvers (fec0:0:0:ffff::1, fec0:0:0:ffff::2, fec0:0:0:ffff::3), so you can put any of these addresses on router and clients will use them to reach local resolver