Dear Mirjam, I have several thinks to be discussed.
2. intended use of the addresses? ----------------------------------
Special policy would only be needed for addresses needed for the Exchange Point medium itself (usually a layer-2 network). Addresses needed for other purposes (e.g. additional services provided to the members) should be assigned by upstream ISPs.
I am not sure, if all of the exchanges are pure l-2. It is OK for classic european "ethernet switch" IXPs, but in other model it should be different. Some IXPs are not only infrastructure for interconnection and they sometimes offer some public services. I cannot determine all of them, but in example: NTP, traffic statistics, root DNS servers and some other (hope people from LINX or NETNOD should find some others).
It was also discussed if the addresses should actually be announced. It was felt that this is not really necessary, but that some IXPs do it anyway. There was no conclusion if this should be part of the policy (e.g. the micro-allocation policy implemented in the ARIN region does require that the prefix is not announced).
You have to announce addresses for "public" services.
3. definition of an IXP -----------------------
It was generally felt that it is difficult to define an IXP, but that the following refined definition could be used as a starting point:
Three or more ASes and thee or more separate entities attached to a LAN (a common layer 2 infrastructure) for the purpose of peering and more are welcome to join.
What is the goal of this definition? It is to restrict other subjects to use these addresses? If yes, there are also some transit ISPs POPs which fit your definition. We discussed definition of IXP on some forums, but we didn't get right definition. Definition is different on basis of your goal :-)
5. Other issues raised ---------------------- Requests should only be sent by established LIRs or via an existing LIR.
Reverse delegation would have to be done by the RIR (requested also via an existing LIR)
Hm ... So IXP have to establish it's own LIR or borrow this service from it's members ? :-) MK