Issue I am trying to solve: on the router from the ISP I can’t set the DNS servers, and I also can’t use any other router. Though, I can disable its DHCP server function.
I’d like to setup a Mikrotik as a a DHP server so I can use whatever DNS servers I’d like to. With IPv4 is straightforward, but how is it going to work with IPv6 and which IP class should I use?
IPv6 networks usually do not use DHCP for things like this, they use SLAAC.
You can configure the DNS servers you want to use in /ipv6 nd
@pe1chl did I get this right? By disabling DHCP server on the ISP’s router, that might still do SLAAC (Stateless Address Autoconfiguration) and I only need to configure DHCP server for IPv4 plus DNS servers for IPv4 and IPv6 on the Mikrotik?
First describe how your network looks. You have an ISP router. Is the MikroTik device the only thing connected to that and all your other devices are connected to the MikroTik router? Or did you just tack it on the LAN hoping to use it as a DHCP server alongside the ISP router?
As of now there is only one router, the one from the ISP, it is a 5G/LTE router with WiFi and a few ETH ports. I was thinking to disable the DHCP server on it and plug in one of the ETH ports my Mikrotik, use it as a DHCP server only, maybe DNS too (might result waster queries than using an external DNS). The Mikrotik router only has 2.4GHz and 100Mbit ports, while the ISP’s router has 5GHz WiFi 6 with Gbit ports.
Ok when the plan is to keep the devices on the network using the ISP router and the MikroTik router as a DHCP server: that won’t work for IPv6.
I must keep the router from the ISP.
Are you sure that ISP’s router runs DHCPv6, what evidence do you have?
In IPv6 custom DNS can be supplied both via DHCPv6 and Router Advertisement (RA). As @pe1chl noted, with some luck you should be able to provide custom DNS with RA without bothering with DHCPv6 via:
/ipv6/nd/add advertise-dns=yes ra-preference=high dns=<DNS IPv6>
I say with some luck because it depends on ISPs router using lower ra-preference.
I suggest skimming through https://datatracker.ietf.org/doc/html/rfc8106 (feed it to your favorite LLM if you want). Will help to set thinking on the right track.
I am not sure about the ISP’s router running DHCPv6, it might be SLAAC only. Once I get back to that location I’m going to check.
RA custom DNS might work, thank you @Kentzo !
I’m going to solve this thread, and I can re-open it if needed.