Comment 4 for bug 1759014

I don't think the two bugs are related.

For this specific, bug, the problem is as follows in the code for src/netword.c

`
if (def->dhcp4 || def->dhcp6) {
        /* isc-dhcp dhclient compatible UseMTU, networkd default is to
         * not accept MTU, which breaks clouds */
        g_string_append_printf(s, "\n[DHCP]\nUseMTU=true\n");
        /* NetworkManager compatible route metrics */
        g_string_append_printf(s, "RouteMetric=%i\n", (def->type == ND_WIFI ? 600 : 100));
        if (g_strcmp0(def->dhcp_identifier, "duid") != 0)
            g_string_append_printf(s, "ClientIdentifier=%s\n", def->dhcp_identifier);
    }
`

It's literally hardcoded to write 2 or 3 dhcp options: UseMTU, RouteMetric and ClientIdentifier.

This bug appears to be pointing out that at least provide the option to add UseDNS=false, and more generally, allow the ability to configure all the DHCP options supported by systemd-networkd