VLANS with internet access

[eduardomontiel970808566]

Hi.

I am trying to create three different vlans and connect a modem in each of them to provide internet access.

What can I do so that the IP of the modem does not interfere with the IP of the vlan?

if I need all the vlan to communicate with each other.

For example I have three networks.

192.168.1.0
192.168.2.0
192.168.3.0

vlan 10
vlan 20
vlan 30

Modem 1
192.168.1.254

Modem 2
192.168.2.254

Modem 3
192.168.3.254

What IP can I put to the Vlan to be able to activate the IP routing and there is communication with all the VLANs.

[balaji.bandi]

If this is the VLAN SVI created and ip routing enabled, they able to communicate each other by default in theory.

but we do not know what is the device here how you configuring ? and your network connect to modem1/2/3 to switch or separate network?

best is take a white paper, make small network diagram and post

users -----Switch -----modem1

                              ------ Modem2

                             ------- Modem3

make sure you do routing correctly on switch., if this is not the case explain with diagram.

[eduardomontiel970808566]

Here is the diagram.

My main question is which IP I can assign to each vlan so that it does not conflict with the IP of each modem.

for example

#interface vlan 10
# ip add 192.168.1.254 255.255.255.0

I can not assign that IP because it is the IP that Modem 1 has

[Georg Pauwen]

Hello,

what modem(s) is/are those ? Typically, the modem dish out IP addresses to whatever is connected to them. If you set your Vlan SVIs to 'ip address dhcp' you should get an unassigned, available IP address from the modem(s).

[balaji.bandi]

Nice Diagram and good input.

Do you have control on the Modem to have some static route back to switch.

if the modem using .254 you can allocated to switch SVI as below :

#interface vlan 10
# ip add 192.168.1.1 255.255.255.0

#interface vlan 20
# ip add 192.168.2.1 255.255.255.0

So on

hope Modem does the NATing for the respected IP address, since Switch dont have capabilities of NAT

make static router

192.168.1.0 255.255.255.0 to 192.168.1.254

192.168.2.0 255.255.255.0 to 192.168.2.254

Allocate the device connected port to respected vlan access vlan 10  - PC / device gateway is 192.168.1.1