The proposal says, "A nice de-facto standard would be to print the dot at the route netmask boundary". This will not work consistently because one does not (typ

The proposal says, "A nice de-facto standard would be to print the dot at the route netmask boundary". This will not work consistently because one does not (typically) know the netmask of a remote host, so this will result in IPv6 addresses being written differently locally and remotely (e.g., the address of a local DHCPv6 host in a /112 written as 20010DB80000000000000000..1 and remotely, perhaps, as 20010DB800000000..1 if SLAAC is incorrectly assumed. Thus they often will not match, complicating, for instance, help desk calls correlating users client IP address to server-side logs. One solution is to always do [zero] compression [only] at the longest run of zeroes, which is what the existing IPv6 address syntax does, i.e., consistently canonical behavior. Aside: this work is related to the reverse-engineering of IPv6 netmask remotely: http://conferences2.sigcomm.org/imc/2015/papers/p509.pdf http://conferences2.sigcomm.org/imc/2015/papers/p509.pdf