Easiest way to connect VLANs to internet?

[Gerontius]

I'm currently trying to design a network in Cisco Packet Tracer.

The network has three VLANs, on its switches, each of which is completely separate from one another with no trunking.

What I'm trying to do now is show how the network will connect to the internet. I'm unsure what the easiest and simplest way to do this would be for all the separate VLANs. Does each one require a separate router in order to connect to the internet? Is there an easier way to do it than that?

Would appreciate any comments or advice people can give on this, or links guiding configuration of a network with requirements like that I have described here.

[Jon Marshall]

I don't use PT but no you don't need to use a router per vlan unless you want to emulate separate internet connections per vlan.

It really depends on your topology but usually to emulate the internet you can simply have a router with a public IP or loopback address and connect that to a  L3 device in your LAN.

If you have a switch per vlan then you need to connect all the switches to a L3 switch ideally and then connect the L3 switch to your internet router.

In other words you need a L3 device in your LAN for routing the vlans and then you connect the L3 device to the internet router.

That is a general answer.

If you want specifics then post a diagram of your layout and we can help more.

Jon

[Gerontius]

O.K. I might try to do that.

Does anyone know any guides to accomplishing that in Packet Tracer or now the terms that are used to describe it so that I could try to look them up?

[Ganesh Hariharan]

Hello,

I don't think it is possible to releastic to replicate Internet connection on PT or any other lab gear. But have look on the document which is bit closer to your simulation.

https://learningnetwork.cisco.com/docs/DOC-11035

Hope it Helps..

-GI

[devils_advocate]

Do you have three separate switches or one switch with three vlans?

If you have one switch with three vlans, you need to look at the 'router on a stick' configuration whereby you trunk a port from the switch up to the router and the default gateways will be subinterfaces of the physical router port. This will mean (by default) that the Vlans will be able to talk to each other, although you could mitigate this using Access Lists.

If you have three switches then you need a router with three separate ports, each port will have an IP address which will act as the default gateway for its corresponding vlan. Again, you will need ACL's to stop the Vlans talking to each other.

It really depends on what you are trying to achieve.

I am not sure how you would simulate 'the internet' in packet tracer, perhaps connect two routers together via a /30 serial link and setup NAT on one of them.

Cheers