Vlan switch and subinterface vlan

[ATtheincredibleaf]

I have an 8 port L2 switch which has 3 ports in VLAN 10 and 4 ports in VLAN 20

Port 1 of the switch is a trunk port connect to FastEthernet 0 of my Cisco router which is doing inter VLAN routing between both VLANs by using the following commands

interface FastEthernet0.10

encapsulation dot1Q 10

ip address 192.168.0.1 255.255.255.0

!

interface FastEthernet0.20

encapsulation dot1Q 20

ip address 10.10.0.1 255.255.0.0

The router also has 8 switch ports and I would like to assign 2 ports to VLAN 10 and another 2 to VLAN 20.

If I do the following, does it do what I want?

interface Vlan10

no ip address

!

interface Vlan20

no ip address

!

interface FastEthernet1

switchport access vlan 10

no ip address

!

interface FastEthernet2

switchport access vlan 10

no ip address

!

interface FastEthernet3

switchport access vlan 20

no ip address

!

interface FastEthernet4

switchport access vlan 20

no ip address

Thanks.

[Jeff Van Houten]

You need to list the model numbers of the equipment and the software versions. There are different answers depending on those factors, but if you're running an older router like I think you are, you're most likely going to have to cross-cable the 2 switches and get rid of the svis on the router.

Sent from Cisco Technical Support iPad App

[ATtheincredibleaf]

The router is an 1801 running IOS 15.1. It has 9 switch ports with FE0 capable of being used as a trunk port.

The switch is a TP Link SG3210 layer 2 managed switch.

[Jeff Van Houten · Accepted solution]

If fe0 can be a trunk port, then remove the sub interfaces, put in switchport mode trunk and put the ip addresses for the 2 Vlans on the svis.

Sent from Cisco Technical Support iPad App

[ATtheincredibleaf]

Thanks!

I cannot use FE0 as a trunk port only divide it into subinterfaces, but you've helped me get the SVI vlans working by using one of the switchports (fa1 - 8 ) as a trunk.

This is how I originally tried to get intervlan routing working but couldn't and found the subinterface method.

Here's a test solution in case anyone else has this problem

On the layer 2 switch, Ive plugged a NAS storage device (192.168.200.2) into port 7 and set that port as a GENERAL port with a PVID of 50 (Port VLAN ID also known as VLAN ID).

Port 8 is set up as a TRUNK port, trunking PVID 50 and this connects to FE8 on the Cisco which is the corresponding trunk port.

On the Cisco, I have the following config...

vlan 50

name TEST

!

interface FastEthernet8

switchport trunk native vlan 50

switchport mode trunk

no ip address

!

interface Vlan50

description TEST

ip address 192.168.200.1 255.255.255.0

This works great.

One last question, why would someone use subinterfaces or the above method of inter vlan routing?