SG200-08 inter-vlan routing

[dgkurtz]

I'm new to this forum and not too technical.

I would like to connect a non-VLAN aware router to port 1 (or other port), create VLAN 2 (port 2&3), and VLAN 3 (port 4), connecting computers to them.

Can the SG200-08 be configured to allow all devices on VLANS 2 & 3 get to the internet on the router?

And will DHCP work from DHCP server on the router?

If so, where would I go to see an example on how to set the switch's configuration for this?

Thanks much.

[Julio E. Moisa]

Hi

Below you will find the configuration for the Router and switch:

ROUTER

interface fa0/0
description INTERNET
ip address <public IP and its subnet mask>
ip nat outside

Create sub interfaces where you are going to create the gateways for each vlan. 

interface f0/1
description P2P-TO-SWITCH
no shutdown

interface f0/1.2
description GATEWAY-VLAN2
encapsulation dot1q 2
ip add 192.168.2.1 255.255.255.0
ip nat inside

interface f0/1.3
description GATEWAY-VLAN3
encapsulation dot1q 3
ip add 192.168.3.1 255.255.255.0
ip nat inside

Create an access-list to match the internal subnet to be translated to the public IP through the PAT. 

ip access-list standard PRIVATE-NETS
permit 192.168.2.0 0.0.0.255
permit 192.168.3.0 0.0.0.255

Create a PAT

ip nat inside source list  PRIVATE-NETS interface fa0/0 overload

Create a default route 

ip route 0.0.0.0 0.0.0.0 <IP next hop to the ISP>    The next hop IP should be the same segment like the IP under the interface fa0/0

DHCP configuration

ip dhcp pool VLAN2
network 192.168.2.0 255.255.255.0
default-router 192.168.2.1
dns-server 8.8.8.8 4.2.2.2

ip dhcp pool VLAN3
network 192.168.3.0 255.255.255.0
default-router 192.168.3.1
dns-server 8.8.8.8 4.2.2.2

Then exclude the gateways. 

ip dhcp excluded-address 192.168.2.1 192.168.2.1
ip dhcp excluded-address 192.168.3.1 192.168.3.1

SWITCH

vlan 2
name VLAN-X

vlan 3
name VLAN-Y

interface fa0/1        <---- Port connected to the ROUTER
description P2P-TO-ROUTER
switchport trunk encapsulation dot1q
switchport mode trunk
no shutdown

switchport trunk allowed vlan 2,3 (optional)

Configuring ports for computers:

interface fa0/2
switchport mode access
switchport access vlan 2
no shutdown

interface fa0/3
switchport mode access
switchport access vlan 2
no shutdown

interface fa0/4
switchport mode access
switchport access vlan 3
no shutdown

Please rate the comment if it is useful

:-)

[dgkurtz]

Thanks for your prompt reply.  I guess you are saying that the SG200-08 can do inter-VLAN routing, without using a VLAN-ware router, right?

I think your instructions are CLI commands?  I'm not familiar with them, but can learn.

Can this setup be done via a browser, via the switch GUI?

[Julio E. Moisa]

Hi

You are welcome  :-)

In order to make inter vlan routing you need a router or layer 3 switch, I think the Cisco SG200 is layer 2 only. You are right, the commands are for CLI, but the links below can be useful for the configuration via GUI:

Vlan and access ports. 

http://sbkb.cisco.com/CiscoSB/GetArticle.aspx?docid=67844b99e2da4a7f88db0c588197487d_Creating_VLANs_on_Cisco_Managed_Switches.xml

Trunk Interface

http://lachlanmiskin.com/blog/2012/08/01/cisco-sg-200-08-trunking/

What model of router are you using?

[dgkurtz]

I was planning to use an old DLINK DIR655 (not CISCO), non VLAN aware router.

So I'm confused. Are you saying that the SG200-08 can not be configured to do what I want to do?  I need both VLAN 2 (port2) and VLAN 3 (port3) be able to access the router port (VLAN1 port1).

[danjsnooks]

The SG200-08 can not be configured to do what you want, it is a layer 2 device.

Julio's original reply was very detailed, and for someone with a Cisco router also very helpful. Not helpful in your situation however, unless you replace your DLink router with something useful.

Please understand though, you can configure the SG200-08 to use VLANs but it won't matter if you do not have a layer 3 device connected to it.

Depending on where you live, an entry-level Cisco is definitely affordable ($123 for a RV215W here in Canada)