BIRD
BGP config on BIRD
Simple BGP configuration with BIRD Internet Routing Daemon
Network

Config
See config here
Out Filter
Send our network to neighbor, but do not sent neighbor connected networks - This will prevent transit via BIRD router.
filter out_eBGP
Connect to neighbor
{
if (net = 30.0.30.0/24) then
{
accept;
}
else reject;
};
protocol bgp bgp_51 # neighbor 51
{
import all; # Give me everything you got
export filter out_eBGP; # send only our network behing BIRD router
local as 15;
neighbor 20.0.10.1 as 51;
default bgp_med 0;
default bgp_local_pref 0;
}