Safely connect two random Networks

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Safely connect two random Networks

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Safely connect two random Networks
Safely connect two random Networks
2022-12-14 09:52:54

Hello TP-Link Community

 

I am a German user, however I am going to post in English to address a larger group of people. I have the situation to setup a network for a two family home. The purpose of the network is to connect the building services (heating, solar power etc) with each other and also to connect the video door station to the two apartments. One of the two apartments will be used by the owner. Now I need a connection between the two apartment networks to the house-network, so that teach resident has access to the video door station with his mobile devices and with the KNX visualization server but not to the building services or the other apartment. The one apartment that is occupied by the owner of the house should have access to the building services.

 

Now I know this could easily be done using VLANS but the residents of the two apartments should decide on their own which hardware they are using and therefore I cannot foresee if this hardware is able to handle VLANS. I also do not want to have to make adjustments if the hardware changes, it should be plug and play. 
 

My guess is that I need a LAN connection between the apartments and the house-network that connects to a central ER7206+OC200. Let's assume port 1 is the house-network, port 2 the video door station, port 3 apartment 1 and port 4 apartment 2. There will be the following rules:

  1. Allow traffic between port 3 and port 2
  2. Allow traffic between port 4 and port 2
  3. Allow traffic between port 3 and port 1
  4. Allow traffic from device IP#.#.#.# behind port 1 and port 2 (if I want to provide access to certain devices, for example a wallbox)
  5. Block traffic between port 3 and 4

 

Or is this thought too simple especially because the apartment networks will have different IPs than the house-network?

 

 

Thanks in advance!

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Re:Safely connect two random Networks
2022-12-16 04:36:48

  @AmonNascaroth 

 

There is no "port access control" so actually you still need to use VLAN. However all these settings can be done on the router side, no need the residents' devices to support VLAN.

 

And actually you also need an Omada managed switch.

See this example:

How to configure Multi-Networks & Multi-SSIDs on Omada SDN Controller

 

The reason you need an Omada switch is because only switch supports rule 4 access control:

" Allow traffic from device IP#.#.#.# behind port 1 and port 2 (if I want to provide access to certain devices, for example a wallbox) "

 

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#2
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Re:Safely connect two random Networks
2022-12-16 07:14:28

  @Somnus 

 

Good Morning,

 

I know that link, I found it myself and also TPLink provided it to me. And I guess I understood one thing wrong: I don't need the IP addresses of the apartments, in the link they are there because they were also setup in Omada and not some other router. Am I Right that only a switch and a OC200 is needed but no ER7206? 

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#3
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Re:Safely connect two random Networks
2022-12-16 13:19:28

  @AmonNascaroth 

 

ER7206(or ER605 a cheaper one) is needed, if you only have a home router.

 

Not all routers support multi-net NAT. If you only have the switch, even though you can create VLANs and subnets, but the main router may only allow one VLAN/subnet to get the Internet. 

 

 

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#4
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Re:Safely connect two random Networks
2022-12-28 19:05:57

I hope you all had great holidays!

 

Internet access is not the issue. It should only be possible to reach devices in a different subnet without the need to make adjustments in one of the networks.

 

I did some reasearch and trial and error the last days and I think I figured out that the functionality I am looking for is sometimes called "Network Bridge" or "Edge Switch". I tried to follow the multi-nets-nat tutorial from TP-Link but without the router and internet part. What I have now:

  • A standalone jetstream switch
  • L2
    • Port 1 = VLAN2 "Wohnung 1", VLAN1
    • Port 9-16 VLAN3 "Hausnetz", VLAN1
  • L3
    • Interface "Wohnung 1": tried bootp and dhcp with the idea to obtain the IP from the according subnet inside "Wohnung 1"
    • Interface "Hausnetz" with the static IP 192.168.1.0
    • DHCP Server with pool1 for IP range beginning with 192.168.1.1

 

Devices connected in Port 9 to 16 get the correct IP address and the switch obtains a IP address from the dhcp server in "Wohnung 1". However, I cannot reach the switch via the IP address assigned by the dhcp server in wohnng 1 (while beeing in the network Wohnung 1). And I do not know how to reach a device through the switch... Moreover, I guess I am missing a static route from VLAN2 to VLAN3 and vice versa. But I have no idea how to setup the route because the IP address from Port 1 is unknown (because it's obtained from the according DHCP server...). I tried port isolation to have  a L2 route from Port 1 to 9-16 but that didn't work.

 

Any ideas?

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Re:Safely connect two random Networks
2023-01-02 15:06:24

  @AmonNascaroth 

 

I did some more research and trial and error. I could manage to access the switch from the other network but I could not manage to see the device connected to the switch that is assigned to the other VLAN/the switch internal DHCP. I also tried with a static route from the IP the switch has been assigned to from the other network to the other vlan but with no success either ... 

 

Any ideas ?

 

 

According to my research my intention shouldn't be impossible but I cannot get it to work...

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#6
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Re:Safely connect two random Networks
2023-01-02 22:26:19

  @AmonNascaroth 

 

Safely connect two random Networks

 

If I take “connect two random networks” literally, I don’t think you can do that with VLANs. VLANs require known and well-defined networks. Also “safely” implies having a firewall that only a router can possibly provide.

 

I haven’t done anything like that myself, but I think you may like to take into a consideration putting an Internet kind of router between your and the other network. Its NAT should make it possible to deal with the randomness of the networks and its firewall should provide required safety. The necessary access to some services on your network may be enabled in that router by configuring port forwarding from the other network to your network.

 

Again, this is just something I would investigate myself if I had a similar requirement.

Kris K
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#7
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Re:Safely connect two random Networks
2023-01-02 23:24:46

  @AmonNascaroth 

 

Thanks. Yeah my next guess is using the router. I spent some time this evening but couldn't achieve anything unfortunately - but I am not also surprised because I haven't had the devices in factory settings :D. I will give it another try tomorrow.

 

By the way I got an order for a two family home now where I actually need a solution :D

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