In a BGP environment where Community is being utilised I read thay BT offers a service in where it can prevent customer routes being advertised to certain peers (EUROPE, ASIA....).
I wondered, why would you want to do this as a Customer AND as a SP?
As a Customer in UK why would I not want my route to be advertised to Asia?
Is it due to the fact that I might only want it to be local to the UK? Or on SP side would it cost additional resources to make this route visible to BGP neighbours in Asia?
I just don't get why you would want to prevent routes from being advertised.