Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
Community Member

dot1q trunk from single switch to multiple switches


Hope you can help please !


I have a single switch with 6 vlans and one trunk port at the main site  This has to connect to a 3 separate locations each with its own switch with a trunked port via a microwave network.


I have run it in packet tracer using a hub as the microwave network.  It works fine in that, I just want to check it would 'actually' work or could it cause problems ?


Diagram from PT below with 3 vlans just for clarification.



Hall of Fame Super Blue

Uhhhh ... Who's doing the

Uhhhh ... Who's doing the routing?


Leo, from looking at that

Leo, from looking at that diagram it's a L2 configuration.


Hall of Fame Super Blue

Martin,  I understand it's a



I understand it's a Layer 2 config but look at the IP addresses of the hosts, hence why I'm asking.  This is not typical of a network implementation.  I am asking because I want the OP to think.


This is a school-related work.  And I, for one, am not willing to spoon feed answers to someone without letting them think for themselves.  


I did see that, I assumed

I did see that, I assumed there was no connectivity required/desired between the networks.

As you say, he needs to ascertain this.




Hall of Fame Super Blue

Sorry, mate.  Didn't want to

Sorry, mate.  Didn't want to "pick a fight" with anyone.  


Your interpretation (along with anyone else) is different to mine.  So I guess we do need to ask more questions.   

Community Member

First of all   'This is not a

First of all   'This is not a school related work' Leo Laohoo. There is no conspiracy here, calm yourself down.  


We are loosing quite a few E1 circuits and they are being replaced with only a few ethernet, so we need to conserve them.

It is indeed a L2 network.  The VLANs don't need to communicate with each other and will terminate into a firewall.  I used the PC's on the left as an interface just.

I was concerned about having one trunk port connect to 3 other switches.  I wasn't sure how they would react as I've ever only used trunks point to point.  

Hence why I used the hub in PT to break a single trunk into 3.  I just wasn't sure how the switches would react to this.

smiley Thanks !




Cisco Employee

I agree with Leo.Basic

I agree with Leo.

Basic understanding is needed its pretty simple. This is just layer 2 network and the subnets with the same range works without any issue. But you have will have problem communicating between the vlans and I hope you dont want to do that hence you want only the vlans across the switches to talk to each other and not between them. If that is the case I dont see any reason why this will not work.


Second if we have mis -understood your query please feel free to shoot the queries you have and we will try to help you on the same.




Hall of Fame Super Blue

Martin & Inayath, I've also

Martin & Inayath, 

I've also noticed that since I've expressed my suspicion about the motive of this thread, the OP has been quiet.  

CreatePlease to create content