Multiple DHCPv6 Server in One Network - Problem?

If I configure my device as client (wireless access point) according to the guidelines of OpenWrt as Client Device and only uncheck "Disable DHCP for this interface" in Network → Interfaces → General Setup, and then restart my device, only DHCPv4 is disabled, but DHCPv6 is still served by my openwrt client device (here as access point), thus resulting multiple DHCPv6 servers active in one network, if I connect all access points with my one main home router.

My questions are:

  1. Is it necessary to disable DHCPv6 server for all AP's?

  2. are there any problems, if there are multiple DHCPv6 servers in one network, as the result of configuring openwrt "OpenWrt as Client Device" according to guidelines and thus let at least 2 or more DHCPv6 servers active (from primary router and connected APs)? conflicts?² any other problems?

² I know this from IPv4, but have little knowledge about IPv6.


You can disable the IPv6 odhcpd as well but it should not cause any issues. Since the APs don't have any GUA address, they will not advertise the default gateway. So worst case scenario is to have multiple IPv6 from the ULA prefixes the APs might have.

Thank you for your answer! I appreciate it :innocent:
I wanna give you some additional infos:

  1. both IPv4 and IPv6 would be enabled in my network (I think it is something called dual stack or so).
  2. All end user devices connected to our wifi would get public IPv6 and (private) IPv4.
  3. My APs have only internal "for configuration purpose" static private IPv4 configured.

Q1) Is your last post still applicable in that case?

Q2) You said the "worst case" is that end user devices would get multiple IPv6 from the ULA prefixes that APs might have. Does it has another "side effects" other than "cosmetics" appearance in network setting of end user devices? like, maybe, router's and AP's odhcpd would talk each other and cause some problems?

While IPv6 is better at sane auto-configurations (so the effects are usually less harmful), you still want to avoid rogue DHCPv6 server just as IPv4 ones and disable them in their configuration.

Ideally, if you don't need them, you'd better disable them as @slh suggested.
Different odhcpds don't talk to each other.

Okay thank you @slh @trendy !
Does it matter if I deactivate DHCPv6 server? I meant, if rogue DHCPv6 server exists in the network, then it doesn't improve anything if I deactivate these APs DHCPv6 servers? correct me if I am wrong.

My point is actually, why the steps to deactivate DHCPv6 server is not mentioned in this manual. I wanna make sure that there are no other issues, if I let my APs are set up like what the manual suggested, other than "cosmetics" appearance in end user devices (by having many IPv6 addresses from APs)??

Most likely the author forgot to mention it.
If the scope of the AP is just to be a dumbAP, then there is a specific guide for that which mentions to disable the IPv6.

Hmm actually I know that dumb ap setting, but I am just, like I said, wondering and wanna make sure that it doesn't results any side effects other than the client's devices having many IPv6 adresses, if I let all AP's DHCPv6 servers be in its default setting, as it is (i.e. not disabling it).