Switch with a Hub instinct on Packet Tracer?

Hey, I was working with packet tracer today and I saw something very disturbing. Now we all know that a hub will flood out packets received to all ports attached with the exception of the one it came in on. A switch, however, is supposed to only send the packet out the port in which it is destined to go. I did a packet tracer today, and the switch sent the packet out all the ports :shock: Could someone please describe to me what is going on?!

Are you sure you were not broadcasting?

Yeah, that's what I thought as well.

I was taught in the academy that you can not broadcast using a switch unless you were using VLANs. I don't have any VLANs on. Very confusing...

Had a quick think about this, and there are a few things to mention.
Every switch has to broadcast at some point, to find out what is attached to what port. So, it's possible the traffic you saw was an ARP cache. But, there is another possibility. If the MAC table in the switch is "full" and there is no free space. In effect the switch will again have to broadcast to get to somewhere else.

So,

Two things to check.

1) Was the traffice some kind of broadcast (ARP etc)?
2) Is the MAC table full, and so the switch has had to do a broadcast?

Hope that made sense, if not, let me know and I'll try and breakdown the answer.

Mr Redranger

A switching network with out any vlan is a flat single broadcast domain,where as every single vlan is a seperate broadcast domain
i.e broadcast from one vlan is not forwarded to another vlan.


so in short every switch will have some short of broadcasting


hope this will help u in solving u r query.