DHCP for ipv6 (DHCPv6) configuration issue

RouterOS Beginner Basics
1

I try run small home ipv6 network. And DHCPv6-server on Mikrotik dont answer to DHCPv6-requests (solicit) packets from PC. Config I got here: http://wiki.mikrotik.com/wiki/Setting_up_DHCPv6

Try on RouterOS v.6.21.1 and 6.27.

My config:

/ipv6> address print 
Flags: X - disabled, I - invalid, D - dynamic, G - global, L - link-local 
 #    ADDRESS                                     FROM-POOL INTERFACE         ADVERTISE
 0  G 2001:dead:beef::1/120                                 bridge-local      no       
 1 DL fe80::d6ca:6dff:fee3:82d7/64                          bridge-local      no       
 2 DL fe80::d6ca:6dff:fee3:82d6/64                          ether1-gateway    no

/ipv6> pool print 
Flags: D - dynamic 
 #   NAME          PREFIX                                      PRE EXPIRES-AFTER       
 0   Local_Pool    2001:dead:beef::/120                        124

/ipv6> dhcp-server print 
Flags: D - dynamic, X - disabled, I - invalid 
 #    NAME                INTERFACE               ADDRESS-POOL               LEASE-TIME
 0    testv6              bridge-local            Local_Pool                 3d  

/ipv6> nd prefix print 
Flags: X - disabled, I - invalid, D - dynamic 
 0    prefix=::/120 interface=bridge-local on-link=yes autonomous=no 
      valid-lifetime=4w2d preferred-lifetime=1w 

/ipv6> nd print        
Flags: X - disabled, I - invalid, * - default 
 0  * interface=all ra-interval=3m20s-10m ra-delay=3s mtu=unspecified 
      reachable-time=unspecified retransmit-interval=unspecified ra-lifetime=30m 
      hop-limit=unspecified advertise-mac-address=yes advertise-dns=no 
      managed-address-configuration=no other-configuration=no 

 1    interface=bridge-local ra-interval=3m20s-10m ra-delay=3s mtu=unspecified 
      reachable-time=unspecified retransmit-interval=unspecified ra-lifetime=30m 
      hop-limit=unspecified advertise-mac-address=yes advertise-dns=yes 
      managed-address-configuration=yes other-configuration=yes

Wireshark show me that solicit packets go out from PC, sniffer on my RB951G show me this packets come to router. What’s wrong with this?

2

Currently DHCPv6 server in RouterOS can do only prefix delegation. It won’t give addresses to individual clients. It will tell you so if you enable dhcp logging:

14:47:17 dhcp,debug,packet recv server: server1 fe80::d041:fdc1:bfb4:cf:1:2 
14:47:17 dhcp,debug,packet type: solicit 
14:47:17 dhcp,debug,packet transaction-id: 87b49f 
14:47:17 dhcp,debug,packet  -> clientid:  00010001 131273a3 080027da d1
14:47:17 dhcp,debug,packet  -> ia_na:  13080027 00000000 00000000 
14:47:17 dhcp,debug,packet  -> oro: 17 23 24 39  
14:47:17 dhcp,debug,packet  -> elapsed_time: 18 
14:47:17 dhcp,debug,packet  -> vendor_class:  00000137 00085d53 4654203
14:47:17 dhcp,debug,packet  -> unknown:  00047769 6e37 
14:47:17 dhcp,debug handling only prefix delegation, discarding..
3

Mikrotik is somewhat broken as a general-purpose standalone router for full-dynamic IPv6 clients running Windows right now. Windows ignores the DNS info in RA messages. Mikrotik only supports putting DNS information in RA. (Mikrotik also doesn’t let you specify the DNS server address to put into RA - it just uses whatever the system is set to use… I want to make the Mikrotik assign itself as DNS server for my LAN, but that’s not possible using only a Mikrotik…)

You should make sure your ND interfaces are set up with “Managed Address Configuration” and “Other Configuration” both being unchecked… unless you run dhcpv6 on a seperate box. (openWRT image on MetaROUTER / KVM could be perfect for this - but it’s silly to need to run a whole virtual box just to hand out the DNS address to SLAAC clients.)
If you leave those checked, then devices are going to skip SLAAC entirely (if ‘managed’ is checked) or waste their time trying to contact a non-existent stateless dhcp server if Other is cheked.

Finally - on windows clients, you can either be silly and let the IPv4 information work for dns, or hard-wire a valid IPv6 dns resolver into the configuration. I haven’t yet tried to see if I can make the Mikrotik’s proxy resolver answer on the well-known mdns addresses that windows falls back to…