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Hi I'm quite new to networking and need some help with a home configuration...

I have an 8 port TP-Link SG3210 layer 2 802.1Q tag capable switch and a Cisco 1801 router.

I set up 3 Vlans on the switch and assign ports to each.

I want to make computers on each Vlan 'see' each other.

Can I set up a single port on the switch as a trunk port out to the Cisco 1801, and use the Cisco to route between the Vlans?

Or do I have to have output ports on the switch, which are assigned to each of the 3 Vlans, connected to the router before the router can route between the Vlans?

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closed as off topic by Grant, mdpc, Ward, Jenny D, Bryan Apr 9 '13 at 19:03

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up vote 1 down vote accepted

The Cisco router can do 802.1q tagging without a problem. On your switch, you'll need to configure the router-facing port to trunk all the VLANs you want to use. Then, you can configure the router to recognize them on sub-interfaces.

On your router:

interface FastEthernet0/0
no ip address
no shut
interface FastEthernet0/0.100
encapsulation dot1q 100
ip address <ip> <mask>
interface FastEthernet0/0.200
encapsulation dot1q 200
ip address <ip> <mask>
interface FastEthernet0/0.300
encapsulation dot1q 300
ip address <ip> <mask>

The computers should point their default gateway to their respective VLAN's subinterface IP. The router will then pass traffic between the VLANs without issue.

If you have any further questions, please respond and include a pastebin link with your configs.

Hope this helps!


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Great stuff. Thanks Keller – ATtheincredibleaf Jun 4 '13 at 14:33

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