WKBI #586, Redploying most of 127/8 as unicast public

Thu Nov 18 16:48:33 UTC 2021

Mark Andrews wrote:
> CIDR is much older than that and we still have to avoid .0 and .255 
> addresses in class C space. 

I use .0 all the time.

> Similarly for .0.0 and .255.255 for class B space and .0.0.0 and 
> .255.255.255 for class A space. Getting everybody you want to contact 
> and the path in between to be clean for 240/4 is more than just a 
> replacement cycle. There is a lot of really old gear out there that 
> still talks to the world and it will never work with 240/4 addresses. 
> If you are selling IPv4 connectivity and your customer is given a 
> 240/4 address but can’t reach some place on the internet that their 
> neighbour with out a 240/4 can who are they going to blame? Can you 
> afford the defective product law suite. You gave then an address that 
> you knew fore well would not work reliably with the Internet as a 
> whole. Using 1/8 is still fraught. At least with 1/8 you are not 
> fighting kernels that need to be modified for which source is not 
> available. 

No address comes with any guarantees. Suppose you are 100% correct. Its 
not the IETF's role to manage the community at large resource 
expenditures, whatever their opinion may be.

The only effort involved on the IETF's jurisdiction was to stop 
squatting on 240/4 and perhaps maybe some other small pieces of IPv4 
that could possibly be better used elsewhere by others who may choose to 
do so.

Joe