broadcast and collision domains

fjohnson

I came across this question but don't quiet understand the answer. It is a graphical question so schetching it would be better.

ROUTER1- Interfaces, (fa0/1-HUB), (fa0/2-Switch)

HUB- 5 workstation.

SWITCH- 5 workstations.

The question
Which of the following statements describe the network?(choose two)
1- There are two broadcast domains in the network.
2- There are four broadcast domains in the network.
3- There are six broadcast domains in the network.
4- There are four collision domains in the network.
5- There are five collision domains in the network.
6- There re seven collision domains in the network.

Answer= 1,6

what I know is each port on the switch is a collision domain when plugged in, but I am not sure how it is seven.

any assistance would be appreciated.
_________________
FJohnson
A+, Network+, MCSE 2000.
soon CCNA.

Headhunter · **Post subject:** **Posted:** Tue Aug 17, 2010 12:51 am

between router and hub 1
5 ports on the switch 5
between router and switch 1

equals 7
_________________
Koen
CCSI #30501 CCNP CCIP CCVP CCSP CCDP Cisco Advanced Wireless LAN Field Specialist Cisco Unity Design Specialist Cisco IP Telephony Design Specialist JNCIS-ES JNCIA-ER JNCIA-EX MCSE MCSA:Messaging

fjohnson · **Post subject:** **Posted:** Tue Aug 17, 2010 7:05 am

So that would mean that the two broadcast are the hub and switch?
_________________
FJohnson
A+, Network+, MCSE 2000.
soon CCNA.

xerobyte · **Post subject:** **Posted:** Tue Aug 17, 2010 7:31 am

Correct, remember layer 2 devices only separate collision domains.

Routers (layer 3) separate broadcast domains.
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techprep · **Post subject:** **Posted:** Thu Sep 16, 2010 10:56 am

I'm guessing this has already been answered, but since I didn't get to answer questions like this on my Network+ exam (it was way too easy, not consistent with the breadth of objectives content ), I would like to answer it anyway:

Two router interfaces = two broadcast domains (by default)

the hub-connected interface is one broadcast domain, and also one collision domain.

the switch actually has six segments (or connections),

counting the one going from the switch to router,
plus the five hosts.

Each one of those switch connections/segments is a collision domain, for a total of six collision domains.

Add the hub-side collision domain, and you have a grand total of:

* 7 collision domains, and

* 2 broadcast domains (hub interface + switch interface).

My Network+ exam would have been a lot more interesting with the type of question you've posted.