RFC3527 link selection sub-option is used to select the "uplink" interface of
dhcrelay in cases where the DHCP server does not know how to reach the dhcrelay
based on the DHCP range. This can happen in weird network configurations like
Mesh networks.
Signed-off-by: Bruno Randolf <br1@einfach.org>
git-svn-id: svn://svn.openwrt.org/openwrt/packages@38447 3c298f89-4303-0410-b956-a3cf2f4a3e73