fff-dhcp: Always announce as default router

Set ra_default to '2' to announce as default-router, even if no default
route or global addresses are present.

This is necessary to be able to reach addresses in fc00::/7 from
clients, because odhcpd does not support sending out routes to clients
via router advertisements.

Signed-off-by: Fabian Bläse <fabian@blaese.de>

src/packages/fff/fff-dhcp/files/etc/uci-defaults/90-fff-dhcp

@@ -29,6 +29,7 @@ uci batch <<EOF
   set dhcp.mesh=dhcp
   set dhcp.mesh.interface='mesh'
   set dhcp.mesh.ra='server'
+  set dhcp.mesh.ra_default='2'
   set dhcp.mesh.ra_management='0'
   set dhcp.mesh.leasetime='12h'
 EOF