Cisco 3750 configuration for static routes per VLAN

ciscocisco-catalystroutingswitchvlan

I have a router that has 4 VLANs configured, with an interface on each VLAN, the router serves as a gateway and provides internet access.

VLAN  |  Interface      |  Function
---------------------------------------
  1   |  192.168.1.1/24  |  DMZ
  2   |  192.168.2.1/24  |  Phones
  3   |  192.168.3.1/24  |  Work Stations
  4   |  192.168.4.1/24  |  Servers

The router has a single cable connecting it to a Cisco 3750 (Gi1/0/1), this connection is setup as an 802.11q trunk.

Other than the trunk port, the other ports on the switch are split among the 4 VLANs.

VLAN  |  Interface
--------------------
1     |  Gi1/0/2-6
2     |  Gi1/0/7-12
3     |  Gi1/0/13-18
4     |  Gi1/0/19-24

How can I set up the switch so that all VLANs have internet access, via their respective gateways on the router, while still allowing any required inter-VLAN communication to occur on the switch itself?

The inter-VLAN communication I require is as follows: 

from   |  to
--------------
2      |  1
3      |  1
4      |  1

I would prefer to run the DHCP server on the Cisco switch, but if necessary I can run it on the router.

System image file is "flash:c3750-advipservicesk9-mz.122-35.SE5.bin"

Best Answer

The switch would need to be a layer-3 switch with routing enabled to allow communication between the VLANs; a layer-2 switch cannot route traffic between VLANs. You would configure SVIs on the layer-3 switch, and the addresses of the SVIs would be the gateways of the VLANs.

You would then convert the trunk link to the router to a routed link:

interface GigabitEthernet 1/0/1
 no switchport
 ip address <ip address> <mask>

You will either need to run a routing protocol between the layer-3 switch and the router, or you will need to configure static routes to the VLAN network on the router.

You will also need a way to have a default route on the layer-3 switch, either specifically configured to point to the router, or through a routing protocol from the router.

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