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New Member

Layer 3 3750g inter vlan route to internet interface

How do you route the inner vlan to the internet? Say you have 3 vlan on switch and one port on switch that is set to no switch port with an IP address that connects to a Rogers modem, what besides the default route of IP address do u do so that all vlan u want to have access to the internet do you need to set???
New Member

Whats a inner vlan?

Whats a inner vlan?
New Member

  By inner vlans ,he means


 By inner vlans ,he means vlans on 1 switch.


New Member

Thank you all for your

Thank you all for your response. Sorry I didn't see them until now!

The switch is a Layer 3 switch model 3750. All vlans will have Internet access until you create a ACL to restrict access. My issue was with NAT and that I simply added a router to the mix. I initially thought I can just hookup to the ISP router, but didn't work for my setup.


On L3 switch, enable "ip

On L3 switch, enable "ip routing"

Put a default route towards modem/router. Use L3 port for connection in-between

NATing will be done on modem/router since 3750 doesn't support NAT

On modem, add routes for your LAN subnets towards the 3750.

On modem/router, you need to change the LAN ip pool to your vlan IPs. Here note that many modems support only one LAN pool.


New Member

  I think you also need to


 I think you also need to map all those switch ports on the 3 VLANs to a routed port on the switch, inorder to allow the users on the 3 VLANs to access internet.

New Member

Hi dear  claudiochiappettaAs

Hi dear  claudiochiappetta

As per my understanding , 1) routed port with ip address connecting to internet link , with default route pointing to nexthop.

2) your users port in respective vlan , nothing else is required for allowing them to access to internet ,

But NAT will be required if your Lan ip not natted on Modem , / what kind of ip you are using on modem link , and for vlan users ?i guesss you could explain in more detail that could help .

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