We are a very small company which currently has the below configuration, with two Internet-Services providers:

  • One only for Internet acces with High-speed Optical-Fiber
  • The second one for phone that also provides a backup ADSL connexion in case of temporary failure of the first one. We switch manually in case of failure.

Former configuration

What we would now like is to have the bellow new configuration, with only one Switch accepting two different entries and managing automatically the switch from the first one to the second in case of internet failure.

 Future Configuration

My question is:

Is the Cisco SLM2048PT-EU suitable for this type of task? What is the key functionality that I should look for this type of task?


  • Link to the Amazon page of the product : link
    – ylnor
    Jan 16, 2017 at 14:16

1 Answer 1


You seem to be confusing switches and routers. Routers route between networks, but switches switch traffic on the same network. Your ISPs have networks, and you will have one or more networks, and you need a router to route between the networks.

You will also need a firewall between the ISPs and your network. It would be rather foolish not to protect your network with a firewall.

Also, from the Cisco web site for this switch model:

NOTE: This product is no longer being sold and might not be supported.

  • Hm, I see. First, let me correct my drawing: Each ISP is in fact an independent router today. What you are telling me is that each ISP router should be connected to a third common independent router (with firewall in between) and then a switch ?
    – ylnor
    Jan 16, 2017 at 15:34
  • If you want automatic failover, the you really need a router. Also, understand in a failover situation, you will end up with a different public IP address, unless you have some provider-independent address space, and you are using BGP to advertise your network to the ISPs. If your business is providing a service like a server that outside users are using, then the server will seem to change addresses.
    – Ron Maupin
    Jan 16, 2017 at 15:39
  • This won't be a problem for us if service is suspended for a while. Thanks a lot for your help!
    – ylnor
    Jan 16, 2017 at 16:20

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