I came up this puzzling issue today. Within the rack there is a Vigor3900 router connected to a 48port Dell switch. I cascaded it to a 24port unmanaged TP link one since we needed to cater for about 65 network plugs. No VLANS, no configuration in Dell, just as they were bought.
First I noted this strange, a Ricoh network printer wouldn't pass traffic despite its static IP (connected to socket coming from the TPlink). For testing purposes I used a cheap switch, plugged it in the network socket and connected the Ricoh to it. It worked.
I got some sporadic complains from users that some sockets don't work but since the pandemic and moving to home, office was almost empty so didn't delve into.
Today disaster struck. Anything connected to TPLink wouldn't pass traffic, wouldn't get DHCP, if I used static again wouldn't pass traffic, all LEDs on and blinking.
Power cycling both switches didn't help either. I presumed TP link was dead so I got a desktop Cisco (I assume those previous Linksys) to replace. Same failure again, no traffic, all LEDs on and blinking.
All sockets connected to Dell work. All sockets connected to TPlink (and later Cisco) don't.
Has anyone of you came across this similar? Am I right to assume that I might need a second Dell switch to cascade as they probably work better together?