old mac can't find new mac for migration
I am trying to set up my brand-new iMac El Capitan and transfer everything from my old iMac running OS X 10.6.8. The new Mac finds the old one readily, using Migration Assistant on both computers, but the old one keeps searching. Then the new one tells me that the old one, whose name it knows, isn't available. I'm using WiFi, for lack of Thunderbolt or FireWire (?), whatever they are. I could detach the ethernet cable from our wifi modem, if that would work better, and I have a backup Gdrive mini, and maybe that would be easier still.
There is another identical question, from 2014, on the forums, but the answer doesn't seem relevant--I did not get a screen asking about transfer when I first started up the new iMac. (I also managed to get to a screen insisting upon a keychain password and it would not accept the password I set up initially at first startup. What is going on? I've never struggled with any of our Macs going back to '83 like this one!)
Many thanks for any bright ideas!