May I disable or uninstall odhcpd if not using DHCP?

I have a main router that is responsable of DHCP leasing, DNS and firewall at home.

And there is a wifi AP (and provides switch for local ethernet access to) in another device.
That device does not provide any service, just AP to lan and other two VLANs (IOT and guest).
So following guides from oneMarcFifty I have deactivated firewall and dnsmasq, use raw protocol for the iot and guest interfaces (in order to not be able to access the AP from that vlans).

But there still is a odhcpd service active.

I think I can deactivate or uninstall it securely, as the AP does not provide DHCP for the local connected devices, just forward packet to the main router.

But I don't know if that service provides any other needed service (for the AP itself for example).
May I deactivate it with no collateral effects?

You can uninstall it. In the default configuration, odhcpd acts as DHCPv6 and IPv6 Router Advertisement server.

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OK, thanks.

I don't understand very well how IPv6 works, it seems it is being used by default by recent windows versions, as I sometimes see that dns is resolved by default through IPv6.

But the main router will be the IPv6 server too, and it seems to work with the default configuration.

So I will better disable odhcp at the AP.

I won't uninstall them in order to let me easily reconfig the AP as an emergency router just in case the new main router fires up (an reconfigure the ISP router as a temporary router too).

With upgrade safety in mind, it's usually better to disable the service(s) (both dnsmasq and odhcpd) via their configuration file (/etc/config/dhcp, option ignore '1' for dnsmasq, option dhcpv6 'disabled' and option ra 'disabled' for odhcpd), than to remove the services (be it by de-installing the package or disabling their initscript). The reason for this is because the next sysupgrade (with a default image, containing those packages again) will implicitly restart those services, which can easily cause issues in your network. This shouldn't be taken as advice against disabling the services, just that it's more important to configure them as disabled (because conffiles are retained over an upgrade), than to deinstall them (as the state of a service being enabled or disabled is not retained; file changes are retained, removed files (initscripts and the rc.d hooks) are reinstated; sysupgrade/ opkg just have no knowledge if a file was removed intentionally or if the new file coming from the sysupgrade is just new/ unrelated).

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