On 1/26/12 7:35 AM, Cameron Byrne wrote:
1. You don't want to disclose what addresses you are using on your internal network, including to the rir
2. You require or desire an address plan that your rir may consider wasteful.
3. You don't want to talk to an rir for a variety of personal or business process reasons
4. When troubleshooting both with network engineers familiar with the network as well as tac engineers, seeing the network for the first time, ula sticks out like a sore thumb and can lead to some meaningful and clarifying discussions about the devices and flows.
5. Routes and packets leak. Filtering at the perimeter? Which perimeter? Mistakes happen. Ula provides a reasonable assumption that the ISP will not route the leaked packets. It is one of many possible layers of security and fail-safes.
Cb Dear Cameron,
For a reference to something taking advantage of ULAs per RFC4193 See: http://tools.ietf.org/html/rfc6281#page-11 Regards, Doug Otis