net: dhcp6: Send DHCPv6 using multicast MAC

In IPv6, the broadcast MAC address is not used.  Instead, it should use
the multicast address (see RFC RFC2464).

Add IPV6_ALL_NODE_ETH_ADDR macro for clarity.

Signed-off-by: Sean Edmond <seanedmond@microsoft.com>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
3 files changed