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I am buying a new router want to set up my current router in the living room to act as a switch and Wifi access point. See image below, where lines are wired connections.

I've read guides explaining that to use the router as a switch. I need to only use the LAN ports on the back and turn off DHCP and NAT gateway. What I have not found is, can the router still act as a Wifi access point?

I would rather have the Wifi access point from the living room than where the router currently sits. network diagram

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    Physically, the device consists of an access point, an internal configurable switch to which the AP is connected, and a router (generally an embedded software router running Linux or VxWorks). Note that the AP is already connected to the switch, and disabling the router doesn't affect that (as long as you haven't split the subnets or such). – chrylis -cautiouslyoptimistic- Sep 22 '20 at 6:51
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Yes. By turning off dhcp and wan but leaving the WIFI on you are in effect turning it into an access point.

You will likely want to move its management IP to something other then the default, and make sure its in the same subnet as the new routers LAN range, and as you stated ensure DHCP is off.

If your new router includes WIFI, if you have same SSID and password but different channels you will also have almost seamless roaming between the two.

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  • good tip about the SSID, can you provide a link about the WIFI remaining on. I was thinking the same I just couldn't find it anywhere. – OrigamiEye Sep 21 '20 at 19:47
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    LMGTFU - speedguide.net/faq/how-to-setup-seamless-wireless-roaming-483. FYI Ive done this at multiple places. – davidgo Sep 21 '20 at 19:55
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    WRT seamless roaming - no it doesn't work like that, sorry. The device will hold the first SSID it joined as long as its in range, even when the quality is low. To flip to the better AP, you have to lose sight of the first AP for a short time then the device re-establishes to the best AP at that time. To get what you describe, APs like Ubiquiti or something else with a "controller" component are required. – Criggie Sep 22 '20 at 4:21
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    If one can't enable "Seamless Roaming", I would recommend against the same hotspot name if you don't want hard-to-debug slow-network issues. Speaking anecdotally. – Gizmo Sep 22 '20 at 6:44
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    If by "seamless roaming" you mean any device configured with the WiFi settings will connect to either, then yes. If you mean that when you move a device it will switch from one to the other in the most optimal way, then that's a lot harder to achieve without cooperation from the network. – jcaron Sep 22 '20 at 11:03
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I have just done this in my house. I have a new router with a few devices connected (both wired and wireless), and I have my old router wired to it and set up as an access point, with additional devices connected to it (both wired and wireless).

Besides changing the settings on the old router to work as an access point, I also had to connect the cable coming from the new router to one of the four "outputs" on the old router, not to the "input" labelled "WAN". This seems counter-intuitive, but that's how things work if you use a router as an access point.

I also gave the access point a fixed IP address in the settings of the new router; I'm not sure whether this is strictly necessary, but then you can easily reach the access point's web interface to change its settings.

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  • Depending on the router model, you can also set the WAN port to become an extra LAN port in its settings menu. – towe Sep 22 '20 at 5:35
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    @towe I assume that depends on how recent or fancy the router is; it wasn't an option on my cheap old D-Link router :-) – guest Sep 22 '20 at 5:52
  • Don't think of those four ports as "output", think of them as "LAN". You're using this device as s switch on your LAN, not as a NAT firewall, so that's totally normal and intuitive. I've done the same thing with cheap D-Link wifi routers in the past, and currently an Archer C7 to cover a different part of the house than the wifi AP built-in to my cable-modem router. – Peter Cordes Sep 22 '20 at 17:11
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Many routers have a separate Access Point mode. Setting the router into Access Point mode allows it to be both an AP and a switch, I have checked and verified this. I don't think the switch behaviour can be disabled at all in these routers.

I can also expand a bit on @guest's point about moving the router-facing cable from the WAN port to the LAN port. Most such wifi routers effectively have a

  1. Routing block, connected to the WAN port on side and to one port of the internal switch on another.
  2. The internal switch itself which is very nearly unmanaged(unmanageable?) - it has virtually no parameters to control.
  3. A WiFi access point "bridged" to the internal switch via another one of the latter's ports.
  4. The management interface which may sit within (1) or be separate.

Any packet arriving at the internal switch is simply switched blindly. If the destination turns out to be accessible via the AP port, the AP converts the packet to 802.11 from 802.3 format and broadcasts it (and vice versa). Much of the configuration controls either (1) or (3), individually.

The reason I know this is that internet has mostly worked for me on a few occasions even when I or someone else had unknowingly plugged in the WAN (ethernet) cable into one of the LAN ports instead.

@davidgo's suggestion of keeping it in router mode but disabling WAN and DHCP is not the same as AP mode since several Layer 3 functionalities like NAT(which you may not be able to disable individually at all)/port forwarding/UPnP and firewall would still be running on the router consuming CPU cycles and RAM. So if you have an AP mode, use it.

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  • What level 3 functionality are you referring to? It would be good if you could advise the impact you believe this has. Note that I said in effect turning it in to an AP. Not all routers have an AP mode. – davidgo Sep 22 '20 at 6:02
  • @davidgo I think the use of "in effect" was misleading. I understood it as all routers can work as an AP even though they are not sold as such. en.wiktionary.org/wiki/in_effect – OrigamiEye Sep 22 '20 at 6:19
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    @origamieye Yes. – davidgo Sep 22 '20 at 7:16
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    @milind Almost all these SOHO routers make use of a MANAGED switch and the WAN port is just in a separate VLAN. This is often exposed and can be reassigned with firmware like *wrt. WIFI bridging takes place in kernel space, not by connecting to a port. There is no special management port, and restrictions are generally implemented with iptables firewall rules. NAT does not consume CPU cycles unless packets are directed to it in iptables, and stuff between WIFI and LAN is handled at layer 2, so doesn't go anywhere near iptables/packet filtering. – davidgo Sep 22 '20 at 9:16
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    I did not suggest WiFi is on the SOC and know that to be untrue. Its on its own (often Qualcomm or broadcom) chip - but it goes through the CPU, its not directly connected to the switch. Ive had experience making them do things rather outside the norm, and likewise Ive built x86 Linux boxes as core routers. – davidgo Sep 23 '20 at 7:18

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