* [BGP]Adding configuration knob to allow advertise Loopback ipv6 /128 prefix
By default when IPv6 address is configured with /128 as subnet mask in Loopback0 interface, it will be advertised as prefix with /64 subnet.
To control this behavior a new field 'bgp_adv_lo_prefix_as_128' is introduced in DEVICE_METADATA table which when set to true will advertise prefix with /128 subnet as it is.
frr does not advertise route if local route is not reachable, as a result
loopback route /64 is not advertised to the neighbors. Add static route
allows frr to advertise the route to its peers
Signed-off-by: Guohan Lu <lguohan@gmail.com>
