Router with multiple subnets, no managed switch

Router with multiple subnets, no managed switch

Router with multiple subnets, no managed switch
Router with multiple subnets, no managed switch
2024-03-25 16:14:22 - last edited 2024-03-26 08:45:49
Model: ER605 (TL-R605)  
Hardware Version: V2
Firmware Version: 2.1.2

Hello everyone, I am trying to update a small network: the router is an ER605, the AP are EAP610s, the network is managed via an omada software controller installed with docker on a local server.

 

My question is: is it possible to configure the router to have 3 subnets as follows where any device on any of these networks would be able to talk to any other device freely?

  • 192.168.1.0/24 -> router is 192.168.1.1, devices are configured with static IP

  • 192.168.2.0/24 -> router is 192.168.2.1, 192.168.2.2-254 is reserved for DHCP

  • 192.168.100.0/24 -> router is 192.168.100.1, devices are configured with static IP

 

I thought it was going to be as easy as creating the three networks in the Settings -> Wired networks -> LAN and assigning them to all the router's interfaces however this does not seem to work.

Devices with DHCP do not get any IP address assigned to them and devices with statically assigned 192.168.100.0/24 or 192.168.2.0/24 addresses cannot even ping the router at 192.168.100.1 or 192.168.2.1

 

I tried reading forums and documentation and I suspect this has something to do with VLANs, however I am not really familiar with this concept.
I get that each of the three networks I created has VLAN id and that typically there would be a managed switch whose ports would be configured to use one or more of these networks, but is it not possible to do this without a managed switch, just assigning all ports of the router to access all networks? I could not find any information about this, but I do not understand if it's because it's something extremely trivial or extremely dumb/wrong or even impossible...
I also read that some unmanaged switches might drop VLAN-tagged packets, so I tried a point-to-point direct connection to the router, but nothing changed.
Also note that there is no correlation between physical location and the subnet a device should connect to (i.e. any wall plug or swith port and even the APs might be connected to a device on any of the three subnets).

 

If anyone could point out any errors I made, or point me in the right direction if I am approaching this the wrong way I would be extremely thankful

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#1
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Re:Router with multiple subnets, no managed switch
2024-03-26 01:01:42

Hi @GioBonvi 

Thanks for posting in our business forum.

1. If you have set up the VLAN interface, then set up the PVID to the port on the router. This is why you don't get the IP. Set the PVID in port config.

2. TP-Link unmanaged switch does not drop VLAN. It does not touch the VLAN but forward. It should be untagged if you intend to use other devices on the switch because the uplink of the switch determines what VLAN this switch belongs to. Or you can set up the uplink as a trunk and distribute the VLAN to the rest of the ports.

Best Regards! If you are new to the forum, please read: Howto - A Guide to Use Forum Effectively. Read Before You Post. Look for a model? Search your model NOW Official and Beta firmware. NEW features! Subscribe for the latest update!Download Beta Here☚ ☛ ★ Configuration Guide ★ ☚ ☛ ★ Knowledge Base ★ ☚ ☛ ★ Troubleshooting Manual ★ ☚ (Disclaimer: Short links are used above solely for guidance to TP-Link subdomains and are safe and tracker-free. Exercise caution with short links from non-official members on forums. We are not liable for external content or damage from non-official members' link use.)
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Re:Router with multiple subnets, no managed switch
2024-03-26 08:28:22 - last edited 2024-03-26 08:44:02

Thank you fro the prompt answer,  @Clive_A 

 

I found the setting to set the PVID, however I do not think this is what I want to obtain.

If I understand this right if I configure a PVID on each port, then that port will "serve" only the corresponding VLAN (since everything downstream is unmanaged). In my example I could have floor 1 on a VLAN and floor 2 on another VLAN.
However, what I'd like to accomplish is that all ports serve all VLANs. Someone else suggested that this would be accomplished by having a managed switch downstream of the router with ports configured in trunk mode: is that right? Is it necessary to introduce a managed switch? Can the router not act as one?

 

Thank you for your help

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#3
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Re:Router with multiple subnets, no managed switch
2024-03-26 08:32:45

Hi @GioBonvi 

Thanks for posting in our business forum.

GioBonvi wrote

Thank you fro the prompt answer,  @Clive_A 

 

I found the setting to set PVID, however I do not think this is what I want to obtain.
If I understand this right if I configure a PVID on each port, then that port will "serve" only the corresponding VLAN (since everything downstream is unmanaged). In my example I could have floor 1 on a VLAN and floor 2 on another VLAN.
However, what I'd like to accomplish is that all ports serve all VLANs. Someone else suggested that this would be accomplished by having a managed switch downstream of the router with ports configured in trunk mode: is that right? Is it necessary to introduce a managed switch? Can the router not act as one?

 

Thank you for your help

I am not able to access your URL because we blocked it. Company ACL.

Please paste it directly in the reply.

What you understand is correct. Set it up as the trunk. And non-VLAN-tag supported devices will not be able to use the VLANs but the PVID-defined VLAN. That's what you can do with the unmanaged switch.

If this is not what you want, you'd like devices in the switch to get different VLANs, tag/untag, then use the switch that supports 802.1Q VLAN.

Best Regards! If you are new to the forum, please read: Howto - A Guide to Use Forum Effectively. Read Before You Post. Look for a model? Search your model NOW Official and Beta firmware. NEW features! Subscribe for the latest update!Download Beta Here☚ ☛ ★ Configuration Guide ★ ☚ ☛ ★ Knowledge Base ★ ☚ ☛ ★ Troubleshooting Manual ★ ☚ (Disclaimer: Short links are used above solely for guidance to TP-Link subdomains and are safe and tracker-free. Exercise caution with short links from non-official members on forums. We are not liable for external content or damage from non-official members' link use.)
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#4
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Re:Router with multiple subnets, no managed switch
2024-03-26 09:00:08

Thanks for confirming this. I just have some more questions/things to confirm, sorry, but I'm new to this and really thankful for the help.

 

  1. If I insert a managed switch downsteram of the router, but upstream of the unmanaged switches (check my previous posts, I added the inline image of my network setup), I can set the ports of the managed switch to:
    • access -> but then each port will only serve one single VLAN and this is not what I need
    • trunk -> but then the client devices will need to be configured to use a specific vlan, is that right? Otherwise if i keep everything unmanaged only the PVID confiugred VLAN will be accessible which is not what I need
  2. If this is right, then I'm beginning to wonder if using VLANs is the right way to obtain what I want.
    In the end what I would like to happen is that the router has multiple networks configured (192.168.1.1/24, 192.168.2.1/24, 192.168.100.1/24) and a client would use one of them based on their interface, independently of the physical location/port they are using. For example I should be able to configure a device with static IP 192.168.1.10 and gateway 192.168.1.1, another with 192.168.100.20 and gateway 192.168.100.1 and another in DHCP receving IP 192.168.2.30 and gateway 192.168.2.1 and they would all be able to talk between them via the router.

 

Thank you again for your help

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#5
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Re:Router with multiple subnets, no managed switch
2024-03-26 13:08:53

  @GioBonvi 

 

It looks like you have the right understanding of the theory, but for some reason you hope to use unmanaged switches. Well, give yourself a favour and forget about this idea. Use only managed switches with VLANs. A VLAN is a broadcast domain, but an unmanaged switch does not understand VLANs. Using unmanaged switches with VLAN will not take you far and will result in issues.

Kris K
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#6
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Re:Router with multiple subnets, no managed switch
2024-03-26 18:58:12

KJK wrote

  @GioBonvi 

 

It looks like you have the right understanding of the theory, but for some reason you hope to use unmanaged switches. Well, give yourself a favour and forget about this idea. Use only managed switches with VLANs. A VLAN is a broadcast domain, but an unmanaged switch does not understand VLANs. Using unmanaged switches with VLAN will not take you far and will result in issues.

Thank you for the suggestion

 

When I started looking into this I simply wanted to improve my existing network setup, which includes lots of unmanaged switches, so I just hoped that it would be feasible with minimal infratructural changes. 

At the beginning I did not know about nor explicitly wanted to use VLANs or managed switches: they simply popped up as I explored this option and I tried to understand how they worked and whether the provided a suitable solution for my problem. 

 

Right now I would say they don't: in fact it looks to me tha whether I replace all my unmanaged switches with managed ones or not, I would still not get what I seek, that is: conencting a device to any port and have it joining one of the subnets according to its network configuration (e.g. On a certain port a device configured with static 192.168.100.10/24 would talk with the router at 192.168.0.1 and on the same port another device configured sifh 192.168.1.20/24 would talk with the router at 192.168.0.1). 

The closest thing I got is to configure the router's and any managed switches' ports in trunk mode and configure each device to use the appropriate vlan tag (which unforunately is not a feasible solution in my environment since not all device supporto vlan tagging)

 

The question I'm trying to answer has now become: is this possibile in any way? (using VLANs or not I do not really care) 

 

Thank yi uagain for helping me udnerrand everything better

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#7
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