what is the purpose of the OPT port on the sg-1100?
is it essentially the same as one of the LAN ports on a normal 4 port router?
is there a resource of connection diagrams for typical configurations such as modem/sg-1100/3 computers?
It's for whatever you like. It can be a separate discrete interface, which is how it ships, or the internal switch can be setup so that it is on the same network as LAN, etc. Some people use it for a second WAN, some use it for a DMZ or separate LAN/guest network.
tnx for the answer, but i was hoping for more details.
i am a retired electronics engineer with 40 years of experience in integrated circuit [mostly analog] design, but i don't know much about networking.
how would i use the sg-1100 to isolate my computers from my IOT devices?
i hope you like my diagram ...
after that you create a firewall rules to prevent comunication between the two interface (LAN/OPT)
ok, but how do i create the firewall rules?
what would they look like?
something like this should work
are the black boxes in your diagram unmanaged switches such as d'link go-sw-5g?
yes they are there as an example