On 12/18/17, 2:36 PM, "NANOG on behalf of Harald Koch" <nanog-bounces at nanog.org on behalf of chk at pobox.com> wrote: > They could use IPv6. I mean, if the mobile phone companies can figure it out, surely an ISP can... Except for cases when it is impossible or impractical to update software on a great number of legacy devicesâ?¦ JL