CSS switch multicast problem in classrom ?

Hi (sorry for English)
In the classroom I have 18 computers and a server. (Macmini). On the server is installed a program to manage these computers Apple Remote Desktop.
Computers and serwers are plugged to CSS326-24G-2S+RM (all 1Gb/s in switch raport). When i want send 500MB file to all computers at once from serwer, switch sends data at (between 10 kb/s 5Mb/s). It does not matter if I send to 2 or 18 computers - speed is very slow. BUT when i changed the switch to TP-Link 1Gb (no smart, no manage) i sended this file to all 18 cpmputers in 10sec.
Where is problem in CSS ? what i must set inside to enable multicast to all computers ?

Hello, please, tell what SwOS version is installed on your CSS326. If it is not the latest v2.4, then you should upgrade and repeat the file transfer.
Does the problem persist if you send the same file to only one computer?
Do all ports have 1G link speed or is there any interface with lower than 1G link speed?
To troubleshoot this issue I would recommend to look in SwOS “Stats” and “Errors” menus to see the forwarded traffic amount and check for any errors during file transfer.

Hi. I am a friend of Garibaldi. A problem was solved before upgrading to 2.5 version.

This the most useful post in every technical forum - “thanks, problem solved!”… and no details, no followup, nothing :imp: