Hi Kai, On 29/05/19 16:33, Kai 'wusel' Siering wrote: > The IXPs I've experienced explicitely prohibit announcment (i. e. routing) of > their space nor announce it theirselves; so why spend another whole /15 as > private address space? Obviously, there is no need for global routabillity, > where is the need for global uniqueness and why can't this be solved > differently (everyone has to cope with IPv4 scarceness, why can't IXPs)? As > the pool of unallocated IPv4 addresses depletes, new IXPs will need to adopt > new strategies, just like their customers.
There are several downsides of using the same address space in multiple IXPs: - IXP participants will not be able to connect the same router to multiple IXPs. This is something that is done quite a lot, especially by smaller networks that connect via remote peering. - It becomes impossible to identify in traceroutes which IXP was crossed. This makes troubleshooting a lot more complicated. - The consequences of address space leaks are more severe. When a participant of a smaller IXP leaks the peering LAN prefix to the routing table this will cause instability at all IXPs that use a prefix that covers the same block. Kind regards, Martin
