Suppose you had a scenario where your AS is multi-homed to two ISPs in, for example, 8 cities around North America. Every site is connected to both ISPs and all of your address space occupies a /19. To your ISPs, you advertise specific /24s in each city. In turn, each ISP advertises your /19 to the rest of the Internet. Everything is going along smoothly until an asteroid crashes into the data center of one of your ISPs in one of the cities. It causes extensive damage and a certain amount of hysteria but to you, it means that only one of your ISPs can truly reach your full /19. That is, the /24 you were advertising in that city is now only reachable via one of the ISPs. But the ISP taken out by the asteroid is still advertising the full /19. Under the circumstances (loss of life, hysteria, sub-optimal routing), would it be appropriate to ask the unfortunate ISP to create a static route on their network to push traffic destined for that particular /24 over to the other ISP's network? This way, the /19 advertisements can be maintained and when traffic destined for that one /24 reaches the asteroid ISP, it can get passed over to the non-asteroid ISP. The route wouldnt be advertised to other carriers.....just used to make sure traffic reached the correct final destination. Will ISPs make these types of accommodations? Suppose the reason was less unexpected than an asteroid. For example, suppose you open a site in a 9th city, but only one carrier is available there. In other words, are ISPs reluctant to slap in static routes for every customer who comes along with some sob story about poor planning and/or unexpected growth? Your comments on this theoretical scenario are much appreciated. -BM