Haven't seen anything about this anywhere else, but received an e-mail today from Bigpipe telling me their DNS server will be decommissioned soon:
We’ve noticed that your modem/router is currently configured to use soon-to-be decommissioned Bigpipe DNS servers. To avoid any interruption of your internet service we need you to update your DNS settings as soon as possible.
The fix for this is pretty simple, just log into your modem/router interface and ensure that the DNS servers are set to be obtained automatically. This will ensure that you’re always using our recommended DNS servers.
If you do need to manually configure the servers, please use the following:
ns1.xtra.co.nz (primary) 122.56.237.1
ns2.xtra.co.nz (secondary) 210.55.111.1
Kinda surprised it hasn't happened earlier
Clint