can i use my old router as a switch with the velop? i need more ethernet ports

Diagnosis

The Linksys Velop AX4200 is a powerful WiFi 6 system, but its primary limitation for power users is the lack of physical Ethernet ports. Because it only provides two ports per node, users often want to repurpose an older router as a network switch. While this is physically possible, a standard router is designed to act as a "gateway," meaning it wants to manage the network, assign IP addresses, and handle traffic routing. If you simply plug the old router into the Velop without reconfiguration, you create a "Double NAT" (Network Address Translation) environment and, more critically, a "Rogue DHCP Server." This happens because both the Velop and the old router will try to assign IP addresses to your devices. When two devices on one network fight to assign IPs, you will experience intermittent connectivity, "Limited Connectivity" errors, and the inability to access shared folders or printers across your home. To make this work, you must strip the old router of its "intelligence" and force it to act as a "dumb" Layer 2 switch.

How to Fix It

To successfully convert your old router into a switch for the AX4200, follow these precise steps. Do not connect the old router to the Velop until Step 6 is complete.

1. Perform a Hard Factory Reset: With the old router powered on, use a paperclip to hold the Reset button for 15-30 seconds. This clears any old static IPs or custom DNS settings that could conflict with the Velop.
2. Isolated Configuration: Connect a laptop directly to one of the LAN ports of the old router using a Cat6 cable. Do not connect the router to the internet yet.
3. Access Admin Panel: Open a web browser and enter the old router's default gateway IP (usually 192.168.0.1 or 192.168.1.1). Log in with the default admin credentials.
4. Disable the DHCP Server: Locate the "LAN Setup" or "DHCP" tab. Find the "DHCP Server" toggle and set it to Disabled or Off. This is the most critical step; it ensures the Velop AX4200 remains the only device assigning IP addresses.
5. Assign a Static LAN IP: Change the old router's internal IP address to be within the Velop's subnet but outside its DHCP pool to avoid conflicts. If your Velop is at 192.168.1.1, set the old router to 192.168.1.2. This allows you to access the old router's settings in the future without having to reset it again.
6. Physical Connection: Power cycle both devices. Connect an Ethernet cable from one of the Velop AX4200's LAN ports directly into one of the LAN ports (not the WAN/Internet port) of the old router. The WAN port on the old router should remain completely empty.

If That Didn't Work

• IP Subnet Mismatch: If you cannot access the old router's admin page after changing the IP, your computer may still be holding a lease from the old subnet. Manually assign your laptop a static IP (e.g., 192.168.1.10) in the network adapter settings to regain access.
• STP Loop Issues: Some high-end older routers have Spanning Tree Protocol (STP) enabled. If the network crashes as soon as you plug them together, look for "STP" in the old router's advanced settings and disable it to prevent a switching loop.
• Hardware Failure/Incompatibility: If the old router is an ancient 10/100 Mbps model, it will bottleneck your AX4200's gigabit speeds. In this case, the only solution is to replace the old router with a dedicated Gigabit Unmanaged Switch (e.g., a TP-Link or Netgear 5-port switch), which requires zero configuration.
• WAN Port "Auto-Sensing": A few rare router models allow the WAN port to be reconfigured as a LAN port in the settings. If you have a model with this "Bridge Mode" or "Switch Mode" option, enable it; this allows you to use all available ports including the WAN port.

Heads Up

• Avoid the WAN Port: Never plug the Velop into the WAN/Internet port of the old router unless that router specifically has a "Bridge Mode" setting. Using the WAN port usually triggers the firewall, blocking your devices from seeing each other.
• Performance Bottlenecks: Remember that using an old router as a switch is a convenience, not a performance upgrade. If the old router is only Fast Ethernet (100Mbps), your wired devices will be capped at that speed regardless of your AX4200's capabilities.
• Power Consumption: Old routers consume significantly more power than a simple unmanaged switch because they are powering a CPU and wireless radios you aren't using. If you are concerned about electricity, disable the WiFi radios in the old router's settings.
• Cable Quality: Ensure you are using Cat5e or Cat6 cables. Using old Cat5 (non-e) cables will limit your connection to 100Mbps and can cause intermittent drops.