This patch adds initial support for vrf in ifupdown2.
Example interfaces file section:
auto swp1.100
iface swp1.100
vrf blue
auto blue
iface blue
vrf-table 10
iproute2 vrf map is generated under:
/etc/iproute2/rt_tables.d/ifupdown2.vrf_map
this patch also adds prelimnary support for 'vrf-table auto'.
But this needs more work.
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
