Advertise a /32 via BGP when I only have the /24 connected

[Ozan1]

So I have a BDI on an ASR, and it is a /24. Let's call it 192.168.1.0/24. I have an ASA connected it to it and its outside IP is 192.168.1.100

I want to advertise to my ISP 192.168.1.100/32 via BGP and not the whole /24. How do I accomplish this?

I did add the 192.168.1.100/32 ge 0 to my "prefix-list" but it didn't get advertised, when I checked advertised routes until I put in

ip route 192.168.1.100 255.255.255.255 null 0.

But then, the traffic got dropped. 

[balaji.bandi]

we need to know your  BGP config how you doing peering with other side. :

But high level below may syntax may help you : ( make sure you understand syntax and test it)

ip prefix-list MyList permit 192.168.1.100/32

router bgp XXX
neighbor x.x.x.x prefix-list MyList out

[Harold Ritter · Accepted solution]

Hi @Ozan1 ,

You need to specify the BDI as the next hop.

ip route 192.168.1.100 255.255.255.255 BDIxxx

Regards,

[Ozan1]

I think this is it! Thank you. I knew I was missing a specific route. 

[Giuseppe Larosa · Accepted solution]

Hello @Ozan1 

>>>> ip route 192.168.1.100 255.255.255.255 null 0

this is a black hole !  a sink that says silenty packets for the host t be simply discarded !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

follow @Harold Ritter auggestions !

Hope to help

Giuseppe