Would this setup cause NETWORK loop

Could some one educate me if this causes a Network Loop

DLink Hub/Switch ==> SW1 (8 Port)

LAN Port
|
|
SW1


M1 M2 M3 M4 M5 M6


All Machine M1 to M6 are connected to the Switch which connects to the ---> LAN Port

SP1 ---> M1
SP2 ---> M2
SP3 ---> M3
SP4 ---> M4
SP5 ---> M5
SP6 ---> M6


Here in the switch 2 Ports are EMPTY / Not-connected....

If SP (Switch Port) 7 and SP8 are connected between then using an ethernet cable.. Would that cause a NETWORK LOOP?


SP7 <

---

> SP8




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First, For this cable to give you any activity at all, it has to be a "crossover" cable. Second, connecting the two ports in such a way is similar to connecting them to a single hub (since the hub is nothing but a repeater, just like a wire is). So if you have STP running on your switch the loop should be detected and one of the ports will be blocked. If STP is not running, then I think that this will cause a loop and you might have problems.

Thats as far as I know.

Thanks Much!

Yes this a loop.Most cheap switches does not have stp and its a matter of a few seconds to happen.I have tried it before and i got around 150.000 packets per second.

I don't see why this would cause a loop.... (or you want to attach a cable to port 7 AND 8 ?? can be I get your question wrong)

Correct me if I'm wrong..
but with 2 switches, how can you create a network loop if you have them only connected by one cable?!

If you have :
[code:1]
[Switch]
| |
| |
[Switch]
[/code:1]

This could create a network loop...

or

[code:1]
[Switch]
| \
| \---[Switch]
| /
| /
| /
[Switch]
[/code:1]
Here STP is required to prevent loops..

Switch will forward broadcast traffic (default config) to all ports EXCEPT the port it came from...

S0lo is spot on. It would have to be a crossover cable to give you a conection between the ports (unless the switch ports have auto-crossover capability) and if you connected two ports in this way you would get a network loop unless you had spanning tree running to prevent it