How to share a printer and DSL connection between VLAN

[blasgonzalez]

Hello,

I've bought a SGE2010 switch. For security purposes we have 2 VLAN's (ADMINISTRATION and EDUCATION) in the same IP range (10.0.0.x) but we need to share the DSL connection and a network printer.

I've tried to create the two VLANS and put in both general mode, and register the ports of the printer and the ADSL router as untagged in the VLAN 1 (the default VLAN) and in each of the other 2 VLAN and with PVID=1, but it doesn't work.

How can I do that?

Thanks in advance

Blas

[John Blakley]

I don't know anything about the SGE2010 switch, but if you're separating the network with vlans, you'll need some method to route between those vlans (either L3 switch or router). If you don't have a way of routing, the only thing that'll be able to communicate on the non-native vlan (vlan 1) are those systems that are in that non-native vlan. For example, if you have 2 computers in vlan 2 and 2 computers in vlan 1, the 2 computers in vlan 2 will be able to see each other as long as they're in the same subnet, but they won't be able to see the pcs in vlan 1. The same goes for the pcs in vlan 1, except the systems in vlan 1 will also have internet access because they'll be able to get to the router (the systems in vlan 2 wouldn't be able to).

You'll need to be able to separate the 2 vlans by subnet. (vlan 1=10.0.0.0/24, vlan 2=10.0.1.0/24, vlan 3=10.0.2.0/24) and then your router will need to be able to support vlans. If it's a cisco router, you'll create subinterfaces that support those vlans and number accordingly:

int fa0/0

ip address 10.0.0.1 255.255.255.0

int fa0/0.2

encapsulation dot1q 2

ip address 10.0.1.1 255.255.255.0

int fa0/0.3

encapsulation dot1q 3

ip address 10.0.2.1 255.255.255.0

Then you'll set the systems that are in vlan 2 as 10.0.1.1 as their gateway and put the hosts on that subnet. Then you will be able to put the printer wherever you want.

HTH,

John

[blasgonzalez]

Thank you John for your answer.

I have little experience in networking and I have a few doubts.

I understand all what you said about the router and the interfaces, but I don’t understand what IP I must set in the printer.

My initial idea was this:

VLAN1 (default or native): Router and shared printers.

VLAN2: Administration Staff VLAN and domain server. Only the PC’s in this VLAN are enrolled in the domain. This server domain is also the DHCP server (Windows 2003 Server).

VLAN3: Educational VLAN. The PC’s in this VLAN don’t have access to PC’s or resources in VLAN2, but they have access to internet and shared printer.

Digging internet I found that the way to achieve that is setting the shared port as untagged in all VLANs and setting the PVID=1.

The ports of VLAN2 are only set as untagged in VLAN2 and with PVID=2. Each port mode is set as “General”

The ports of VLAN2 are only set as untagged in VLAN3 and with PVID=3.

Each port mode is set as “General”.

But this doesn’t work. And I haven’t the slightest idea how DHCP server (in VLAN2) will lease IP’s to all the PC’s on each VLAN.

Thank you

Blas Gonzalez