Inter VLAN Connections

[Mrauch]

Good afernoon,

I am trying to set up a local network with three SG-300-52 switches and my question is regarding inter vlan connections.

My desired setup is as follows:

L3

I

L2

I

L2

But it appears as if the only way for the L2 switches to communicate with the L3 and each other is to assign each L2 its own subnet and only that subnet. Is it possible to have the L2 switch with a .2.X and a .3.X at the same time?  If so, how?  Or do all the switches need to be L3 to have this functionality?

Thanks,

Mark

[andrew.prince]

Mark,

What you are trying to do with non-smb switches is possible with no issues. I sugggest you read any documentation you have on your device type.

Read the below

http://www.cisco.com/en/US/docs/switches/lan/csbms/sf30x_sg30x/administration_guide/CLI_300_1.1.pdf

[Mrauch]

This specifically is what were having issues trying to create. I understand how to configure a Layer 3 switch, my issue is trying to configure the layer 2 switches attached to the network to be able to accomodate multiple subnets on the same switch.

[andrew.prince]

Nice diagram - have you read the URL I posted?

[Mrauch]

The url to the user's manual? I have not found any solution to this problem in it.

[andrew.prince]

The answer is in the manual - read page 408,413 & 417

HTH>

[Mandlenkosi Nkiwane]

Configuring multiple subnets for each switch is like creating multiple vlans on a that switch. Below I am going to create two subnets for two different departments:

vlan database

vlan 100

name Sales

vlan 200

name Markerting

interface vlan 100

description Sales_Subnet

ip address 192.168.1.1 255.255.255.0

ip helper-address 192.168.1.10

ip helper-address 192.168.1.11

interface vlan 200

description Marketing_Subnet

ip address 192.168.0.1 255.255.255.0

ip helper-address 192.168.1.10

ip helper-address 192.168.1.11

Now you need assign ports to these vlans

interface g0/1

switchport access vlan 100

switchport mode access

spanning-tree portfast

interface g0/2

switchport access vlan 200

switchport mode access

spanning-tree portfast

For your uplinks

interface Gig0/10

description Connection to Main_switch

switchport mode trunk

switchport trunk allowed vlan 100,200

Essentially you have two subnets 192.168.0.0 and 192.168.1.0 configured on this switch.

Hope this helps

[Mrauch]

From the diagram you can see we have the layer 3 switch programed properly, but we are not sure what to do with the layer 2 switches because they are not able to propergate the vlans from the layer 3 switch.

To Mandlenkosi Nkiwane: Which switch from the diagram are we supposed to run that on? (Thank you by the way for your response).

[Mandlenkosi Nkiwane]

You need to manually create the vlans on each of the switches that are going to be touching the end devices that need those vlans.

L2SG300-1 and 2 definitely you will need to configure the multiple vlans for the all the subnets that are on the access switches.

L2SG300-1:  Vlan 2 and 4

L2SG300-2: Vlan 3 and 4

In essence every switch along the way to the layer 3 needs to have the vlans that are going to pass through them or else the packets with tht vlan tag will be dropped.

[viswamin]

You could also configure VTP to overcome the VLAN administration portions.

-Vijay

[Mrauch]

Thank you so much Mandlenkosi, this is what I needed to know.

To Vijay: I would but were using the firewall as a router, but thank you for the response as well.

[Mandlenkosi Nkiwane]

I am glad I could help.

Please rate, thanks.

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