I just clean installed Stretch and set up SSH and a hostname in raspi-config.
On occasion it takes several minutes after boot before I can SSH over IP. Sometimes it never happens and I have to power cycle the Pi.
Also, even though I have a hostname set
greypi, ssh to email@example.com has never resolved on Stretch for me. This worked fine in Jesse.
What could be going wrong?
Edit: SSH seems to more reliably work if I wait a few minutes after boot. If I try to connect much earlier it seems to lock me out. I enabled "Wait for LAN" in boot settings in the config and it din't help.
Edit2: I gave up. Sick of not getting mDNS or even SSH half the time. I went back to Jesse and it works a treat, therefore, not my network and not the Pi hardware I expect.