But, as with anything, you have tradeoffs. Routers MUST support the assignment of /127 prefixes on point-to- point inter-router links. Routers MUST disable Subnet-Router anycast for the prefix when /127 prefixes are used.
Anything longer than a /64 will break SLAAC, neighbor discovery, and other v6 “stuff”. If you don’t need these then a /127 is for you. Just know the downsides of a /64 vs a /127. The RFC says you can do it, but it conflicts with the before mentioned V6 stuff. Frankly I don’t care about conserving IPV6 space. Justin Wilson j...@mtin.net --- http://www.mtin.net Owner/CEO xISP Solutions- Consulting – Data Centers - Bandwidth http://www.midwest-ix.com COO/Chairman Internet Exchange - Peering - Distributed Fabric > On Jan 15, 2017, at 11:28 AM, Seth Mattinen <se...@rollernet.us> wrote: > > On 1/15/17 8:08 AM, Justin Wilson wrote: >> -assign a /64 for point to point links (aka the equivalent of /30s). >> Again, don’t think in terms of host count. anything smaller than /64’s >> breaks things. Some providers out there assign smaller blocks, but it >> breaks things and isn’t RFC. Using a /128 is a hot debate at the moment. >> Some folks are willing to live with the stuff that is broken. The whole >> /127 or /128 debate came up due to security concerns mainly. > > > Use of /127 on router links is RFC 6164 > > https://tools.ietf.org/html/rfc6164 >
