[routing-wg]Question about IP block Misusage

On 21-okt-2007, at 21:45, Ali Dinçkan wrote:

> I have a question. I am searhing now what happens if an ISP use IP  
> address
> space that is assigned to another ISP. Is there any technical control
> eleminate this condition? And what is the legal sanction of this  
> misuse?

> This might be intentional or unintentional. But ISP that use  
> another ISP's
> IP address space damage the Internet nature.

This is why it's a good idea to have filters, but if it's happening  
then obviously there is insufficient filtering to stop it. In the  
future, address certificates could help here. Don't know about legal  
issues but I'd assume you'd have a decent case in court.

However, the best way to resolve this is to first contact the party  
announcing the address space, and if they don't cooperate, their  
upstream ISPs. When I used to work at a large IP carrier our policy  
was always that if customers wanted to use address space from other  
ISPs, we'd only do that as long as the other ISP would allow it.