Can't SSH by name on stretch; can on jessie

Question

I just updated my Pi0W's to stretch, from jessie, and now putty won't let me connect by name (e.g. pi@computername.local) like it used to. It does work as expected if I use the IP. But the odd thing is, I still have a jessie machine on the network, and I can connect to it using the above naming scheme (pi@computername works, as well). This is on my local, home network. Any thoughts?

Answer 1

You tried to connect to "stretch" machines with pi@computername.local. This is the domain from mDNS with autoconfigured ip addresses. To "jessie" machines you connect with pi@computername. This is the naming scheme for static ip addresses or from a dhcp server with dyndns and search domains. By specification mDNS will never autoconfigure ip addresses if it find a dhcp server on the network. Try to connect to your "stretch" machines with pi@computername.

Update:
To clarify it: there is an important difference between pi@computername.local (this will address the local domain defined by RFC3927 without using DNS) and pi@computername (this will use name resolution through DNS or entries in /etc/hosts).

Answer 2

This "naming scheme" is due to something called mDNS. If you're using a Mac, it's built in as Bonjour; if you're on Windoze, it's either from MS' dodgy implementation of mDNS, or from iTunes that's been installed on Windoze. You can also install software on your RPi that will add mDNS - an app (strictly speaking a service) called avahi. Installing avahi should resolve your issue, and make your RPi responsive to a name such as raspberrypi.local.

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install avahi-daemon 

And that's it. Let us know if you have any other issues, and we'll try to help.