On second thoughts, despite 'dnsutils' and 'bind9-host' updates 17.04 is still buggy on my two Toshiba laptops (one ancient, one less so). Can take up to three attempts to resolve all repositories with 'sudo apt update' after boot. Alternatively, on first attempts, browsers (Firefox, Chromium) do not connect to sites - but then, after a while do so. Bizarre. Been using Ubuntu since 9.x - never encountered this irritation before. So it's not because I'm using USB stick installations. However, I am, as ever using copper wire at 16-20 Mbit/s - but that's never beena problem before... To actually receive the updates I needed to use the Google DNS 8.8.8.8 on IPV4 - thereafter deleting this. I'm now using two (full install, not 'live) USB sticks with 17.04 booting to them on either laptop - but am holding off upgrading from 16.10 on my main (newer uefi) machine until the issue is fully resolved. On 18 April 2017 at 10:22, David Oser