BGP advertise-map in XOS

[Elie_Raad]

I have a Multi-homed Routers connected to 2 ISPs. I need to Create like an Advertise-map on the Standby Router connected to the Standby ISP to only advertise my Public address if the primary link goes down .

Is there a way of doing it in XOS ?
Thank You,
Elie

[Elie_Raad]

can you please explain more your idea or setup

[Nick_Yakimenko]

Elie, your idea is not correct
Your backup ISP should accept you announces with a minimal localpref
So your prefixes will be accepted only if your first BGP session fails

Our backup ISP does that automatically when we announce prefixes with a specific community:
whois as20850 | grep ackup remarks: | 20850:50 will set Local Preference to 50 for use as Backup

[Elie_Raad]

my idea is to add a static blakchole route and track it by and ip sla , and add this route along with my public prefix in a route-map as an AND operation. so if the static route is there then permit the public prefix to be advertised

[Elie_Raad]

Hi Balaji, thank you for your reply , your configuration is correct which accomplish half of what i am looking for , the other half is that i want to advertise only this public prefix only and only if the connection to the primary ISP Fails. ( i have 2 routers connected to 2 different ISPs)

[Nick_Yakimenko]

They need to only advertise Public address if the primary link goes down .