While watching a networking course I discovered there is (was) a 5-4-3 rule about boundaries of older Ethernet.
I failed to understand notions in the rule.
Below is the picture that, as I understand, demonstrates the 'maximum' configuration for 5-4-3 rule.
E.g. wiki says:
It means that in a collision domain there should be at most 5 segments tied together with 4 repeaters, with up to 3 mixing segments.
What segments are being talked about here? Wiki again says there are 3 kinds of network segments - layer 1-2-3 - basically collision domains, broadcast domains and subnets.
Since 5-4-3 rule talks about 'repeaters' (basically hubs as I understand) I thought that segments is rule are layer 1 segments - collision domains.
But since there are only hubs participating in the rule, isn't all the network a single collision domain? There's nothing like a switch or router to split a collision domain here.
Anyway, even if segments in 5-4-3 rule are for some reason layer 2 segments, I still can't find anything sensible of count 5 on the picture..
Not directly connected with the question, but 4 hubs are of course obvious in the picture, and while I see that computers 'can only by connected to a max of 3 hubs' (let's say), but
- what are 'mixing segments' wiki is talking about?
- is the course it's said that 'only 3 of segments can have computers connected to them'; what does it mean? how a computer can be connected to a segment? does it differ from my interpretation above of only 3 hubs (not segments)?