Much like David said, the route needs to be active in the routing table and then you just need to write an export policy for it.
In my case, what I did was I put in a static route on my border router that routed the IP addresses I wanted to originate to the inside of our network:
set routing-options static route 5.5.5.0/24 next-hop ....
Afterwards I went ahead and created the prefix list and the export policy (I used exact here because I did not want anything else leaking out on accident. You can use different switches that would also export shorter or longer routes)
policy-options {
prefix-list your-ips {
5.5.5.0/24;
}
policy-statement your-ips-to-advertise {
term fgcu-ips {
from {
prefix-list-filter your-ips exact;
}
then accept;
}
term reject-all-else {
then reject;
}
}
}
Then the export policy goes into your protocols statement:
protocols {
bgp {
group your-bgp-peers {
export your-ips-to-advertise;
neighbor your-isps-ip-here {
peer-as XXXX;
}
}
}
}
Hope that helps!
SH