Solved: Connect two networks with different subnets

adam.dillon1 · ‎05-27-2016

I have one network that's completely excluded from the rest of the network. It consists of a Allied Telesis AT-8624T/2M Layer 3 switch, a computer and a few PLC devices.

This is the only Allied Telesis switch, everything else on our network is Cisco. The Allied was put in by a vendor.

Our network uses a 10.10.1.X network but this standalone network uses a 192.168.201.x. I need to connect the two networks because a system on the 10.10.1.x network needs to access the computer on the 192.168.201.x network. I'm wondering if I can do that with a Cisco 2960s or if I will need to get a router between the two switches.

I am pretty new to setting up this type of equipment, was suddenly tossed into the mix, I appreciate any help that can be offered. Thank you.

Carlos Villagran · ‎05-27-2016

Hi!

You can do it with your 2960 switch, they support static routing. Please refer to the following link for detailed configuration instructions:

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/12-2_55_se/configuration/guide/scg_2960/swipstatrout.html

You will not be able to perform inter-vlan routing but pointing your static routes to the other switch managed interface you will be able to achieve this. BE AWARE that the other switch will have to have some sort of routing capabilities too or you will have to get a router.

Hope it helps, best regards!

JC

View solution in original post

Tim Y · ‎05-27-2016

Hi,

You need a layer 3 switch (preferably a Cisco as opposed to the Allied Telesis) or a router in order to route between the subnets.

Here are a couple guides you can use for either method:

http://www.internetworkingcareer.com/ccna/configure-inter-vlan-routing/

http://www.internetworkingcareer.com/ccna/configure-router-stick/

What is the default gateway for your 10.10.1.X devices? If it's the 2960 and it has version 12.2(55)SE or above, you create a static route to the 192.168.201.X network pointing to the Allied switch after you give it a 10.10.1.X interface and ensure you're trunking between the two switches.

Let me know what you have to work with. If you're unsure, just letting me know what the network topology looks like and the devices involved would be helpful.

Regards,

Tim

View solution in original post

Carlos Villagran · ‎05-27-2016

Hi!

You can do it with your 2960 switch, they support static routing. Please refer to the following link for detailed configuration instructions:

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/12-2_55_se/configuration/guide/scg_2960/swipstatrout.html

You will not be able to perform inter-vlan routing but pointing your static routes to the other switch managed interface you will be able to achieve this. BE AWARE that the other switch will have to have some sort of routing capabilities too or you will have to get a router.

Hope it helps, best regards!

JC

Tim Y · ‎05-27-2016

Hi,

You need a layer 3 switch (preferably a Cisco as opposed to the Allied Telesis) or a router in order to route between the subnets.

Here are a couple guides you can use for either method:

http://www.internetworkingcareer.com/ccna/configure-inter-vlan-routing/

http://www.internetworkingcareer.com/ccna/configure-router-stick/

What is the default gateway for your 10.10.1.X devices? If it's the 2960 and it has version 12.2(55)SE or above, you create a static route to the 192.168.201.X network pointing to the Allied switch after you give it a 10.10.1.X interface and ensure you're trunking between the two switches.

Let me know what you have to work with. If you're unsure, just letting me know what the network topology looks like and the devices involved would be helpful.

Regards,

Tim

adam.dillon1 · ‎05-27-2016

Both the 2960s and the AT switch are layer 3 switches, so I should be okay there.

The default gateway for the 10.10.1.x devices is 10.10.1.1. The software version on the 2960s is 12.2(55)SE7.

Tim Y · ‎05-27-2016

Hi,

You can't do inter-VLAN routing with the 2960's though. If 10.10.1.1 is the 2960, then you can do the following...

For the purposes of this example let's say:

- 10.10.1.X is VLAN 10

- 192.168.201.X is VLAN 20

- The AT and 2960 switch are connected directly together with a layer 2 connection

Configure on the AT:

Create VLAN 10 if not already existing
Create VLAN 20 if not already existing and untag all ports with it (this step only necessary if everything is on VLAN 1 right now)
On the interconnect between the AT and the 2960, tag VLAN 10,20
Give VLAN 10 an IP address (for this example, say it's 10.10.1.250)
Give VLAN 20 an IP address if it doesn't have one already
Make sure the PLC devices on the AT have the VLAN 20 IP address as the default gateway

Configure on the 2960:

On the interconnect between the AT and the 2960, configure a trunk
Create a static route to the 192.168.201.0/24 network via 10.10.1.250

Regards,

Tim

Prabath Godevithanage · ‎05-27-2016

Hi Adam,

here you have some ideas from others,If I were to do this myself I would try to use the AT switch to do routing for the PLC network using static routes without any additional routers in between.

I've seen similar setups from PLC vendors in the past and they would just assign the IP and the mask to the PLCs but not the default gateway,so watch out for that one too

Cheers,

Prabath

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