Managed and Unmanaged switches on the same network

[KeithSouthAfrica]

We currently have 3 companies in 1 building running off 1 fibre connection (100 meg line) . This is the most cost effective method for us.

The first switch is a managed switch (where the fibre comes in)  which has a Vlan for voip phones and then the IP's for the whole building are set by DHCP server, we have a cable running from this switch to the 2nd company which has an unmanaged switch and then a cable running from this unmanaged switch to the 3rd company that also has an unmanaged switch. Obviously we are getting a lot of conflicts as the network grows.

We want to change the setup so each company has there own Vlans - I am aware that the 2 unmanged switches will need to be replaced but what i am not sure about is if we can just buy a small 4 port managed switch to create the VLan then plug the existing unmanaged switch into the new managed switch.

I don't want to buy two new 48 port managed switches if i can help it , I would rather buy two 4 ports managed switches and use the existing 48 port switches I have running off the managed switch

[Georg Pauwen]

Hello,

--> We want to change the setup so each company has there own Vlans

What is your current Vlan topology, do these companies share the same Vlan ?

[KeithSouthAfrica]

No currently the only Vlan is setup in company 1 to control the VOIP phones - not computers / IP camera / printers etc are on this VLan only the telephone system. All the computers etc are assigned IP by the router

[marce1000]

 - Basically this good answer 'says it all' : https://community.cisco.com/t5/switching/vlans-and-unmanaged-switches/m-p/1924676#M213706 , in general once you get an expanded intranet get rid of unmanaged switches (indeed). Better overall network management such as vlans :centrally managed with vtp , trunks , security (integration with ISE (e.g.)), and others...

 M.

[Joseph W. Doherty]

Unclear why you need two additional VLAN switches; possibly you don't need any at all.

With just one additional VLAN switch (this assuming it and your existing switch support VLAN trunks), break connections between all 3 switches.  Place new additional VLAN switch next to 2nd company switch.  Connect all 3 pre-existing switches to it.  Trunk link between your existing VLAN switch and the new VLAN switch.  This will allow you to have a VLAN, unique, for 2nd and 3rd companies.

Two other possible choices.  If you can run link from 3rd switch to your VLAN switch, and assuming you have a free port for 3rd company link on your VLAN switch, this too would support a VLAN per company.

Or, if you cannot run link directly from 3rd switch to VLAN switch, but if you can run a new link between 2nd company switch location and VLAN switch, also again assuming you have a free port on VLAN switch, insert another unmanaged (e.g. 4 port) switch between your VLAN switch and 3rd company switch.  Again, you'll be able to have another unique VLAN for both the 2nd and 3rd company.