The problem is not the name resolving, because ping, telnet and other IP-tools doesn’t work or work unstable. For example - I start ping command from terminal from street (this terminal after connected to server across unmanagement “D-LINK” - “Mikrotik” - “Tenda” switch. I think this problem is a cheap switch “tenda”, because if I connect to mikrotik or trendnet - problem is over. But I can’t to change this hardware and I need to use IGMP snooping. Also, only 2 switches can works with VLAN’s.
Wait a minute. I remembered the main thing - there was a problem with the printer even with a direct connection to the same switch or router. He simply disappeared from the network after a while and his restart helped. But after enabling this function - the printer stopped disappearing from the network.
Intresting, was printer set to static ip?
What brand was it?
of course, only static. Model is - EPOS80300 from compostech.net
First time I thinking about hardware problem, but I have the same printers in other places.