Vlan on SG200 - Am I missing something?

[andrewdmorton]

Hi.

Im setting up a network with a vlan config  - one 'inside' and one 'outside' clan. Both vlans should not be able to talk to each other, but they should both be able to contact the default gateway and DHCP server.

Therefore we have 2 vlans and 1 access port(?).  They use the same DHCP server, and also the same IP range and subnet.

My question is this:

1) Is this a good idea - 2 vlans with the same range and subnet?

2) If it is ok, do I need anything else - i have a fear I need to buy another router (L3).  Because there is no bridging between subnets and ranges, I assumed that I could do it all without a router. If I do need to buy another router, can one (a simple one) be recommended, or should I return the SG200 and replace it with another device to make the number of  physical network devices low (we don't have a lot of wired connections...)?

Many thanks.

Regards,

Andrew

[Robert Mogan · Accepted solution]

Hi Andrew

2 vlans with the same range and subnet - its not a good idea and will not help you in any way.

SG200 is a layer 2 switch.  As you already know you need a layer 3 capabilities to route between vlans.  An SG300 is the layer 3 big brother to the SG200 and costs a bit more.  If you're on decent terms your dealer might let you swap up.

If the vlans are to be kept separate then you should be ok with theSG200.

You can steer a car with your feet but it doesn't make it a good idea either (Chris Rock) (:

[Robert Mogan]

And I'm not paying proper attention ):

Forgot the dhcp relay bit.  You would need layer 3 routing for the dhcp relay to get from the lan that doesn't have a dhcp server to the one that does.