Hello all—
I know I’m close to an answer, but close enough…
I’m a Comcast static IP business customer. Comcast is now also offering me a ./56 V6 prefix (assigned by DHCPv6).
First, since Comcast truly does not want to talk about this. I believe the following is true?
Assume my prefix is 1111:2222:3333:4400/56 and my DHCPv6 assigned address is 1111:2222:3333:4410:xxxxxxxxx
- I assume I can assign an internal LAN address of 1111:2222:3333:4401/64
- I tell Mikrotik to route the LAN space out of the WAN interface (not by address)
Has anyone got this to work?
First - you don’t need a WAN-side prefix assignment at all - the router is perfectly happy forwarding IPv6 to/from the world using only the link-local addressing (fe80::/16)
Second - when you receive the /56 - it goes into a pool you specify in the dhcpv6-client settings - and interfaces can pull addresses from that pool.
(or not)
If you know that your prefix is static (and as a business customer, you should INSIST that it be static to you, even if it needs dhcpv6 for routing purposes) then you can just assign prefixes to whatever interfaces you like
1111:2222:3333:44xx::/64 is a “generic” definition of your prefixes - I would suggest that the first thing you do is create an “unreachable” route for your master /56 prefix to avoid ping-pong traffic to unused prefixes.
/ipv6 route add type=unreachable dst=1111:2222:3333:4400/56
Then put whatever prefixes you need onto your lan-side interfaces:
e.g.:
/ipv6 address add address=1111:2222:3333:44c0::1/64 interface=ether9
No need to specify from-pool unless your prefix is dynamic (which can be a collossal headache for a business network with servers/resources that you’d like to be able to reach via a known address, which is tough if your prefix is want to change w/o your initiating the change…)