[c-nsp] Help with unique BGP setup

[Lobo]

We're trying to do a custom bgp setup for one of our customers but I'm 
not sure if it's even possible with IOS.  Our network has its primary 
upstream connection in a different city from where this customer will 
connect.  However each city has its own local internet connection as 
well for backup purposes.  The market that this bgp customer is to be 
turned up on uses the local isp connection as its primary due to 
capacity issues on the intercity going back to the core city.

This customer's requirements for bandwidth can be met if they use the 
local connection only but should the connection go down, they would most 
likely saturate the intercity connection and impact everyone else.  What 
has been proposed is that they will use the local connection to get 
internet access and should this access go down, they want the bgp 
session to be dropped or something equivalent that will make sure they 
don't go over the intercity.

To my knowledge I know of no configuration that can drop a bgp session 
based on some next hop attribute.  Is there some way to control this 
customer's traffic as stated above?  Any examples you guys can offer?

Thanks.

Jose