How to cascade the routers?
How to cascade the routers?
I’m working with two routers—one upstairs with built-in DSL and a VOIP phone, and another downstairs that handles a DSL connection and wireless devices. I want to set up the upstairs router as a true router and assign separate subnets to all computers and wireless gadgets. My goal is to link the upstairs router to a different subnet, say 192.168.2.x, while keeping the downstairs router on 192.168.1.x for its DSL connection and VOIP. I’ve learned this process is known as a LAN-to-WAN cascading configuration, where you connect an Ethernet cable from the first router to the WAN port of the second. My challenge is that the second router’s WAN port is a DSL port. Can someone suggest a way to use an Ethernet port inside the router for the WAN connection instead? Or is it possible to repurpose the DSL port as an RJ-45 interface for Ethernet? Thanks for any advice!
On products for everyday use, achieving your goals might be challenging. Things would change if you were managing a router, allowing you to configure each port individually. The positive side is that affordable consumer routers with RJ-45 WAN ports are readily available. Choose the most budget-friendly model with all necessary gigabit ports and the Wi-Fi 802.11 standards you need.
Your router can run third-party firmware such as OpenWRT. If that firmware treats the switch ports as individual interfaces, you can set one port to function as a DHCP client on the first network, group the remaining ports into a subnet where the router serves as a DHCP server, designate your first router as the default route for traffic in the second subnet, and turn on NAT for packets sent to it.
Sure, you're wondering if the ports on the switch need distinct interfaces. You've already tested assigning a second IP to the router and connected devices successfully, which worked. The router then connects to the lower floor via 192.168.1.x and to your computers using 192.168.2.x, so it was almost there. However, you're still experiencing internet issues through that route. It looks like the router can create two subnets but isn't able to route traffic between them.
It seems you should configure the DNS and default gateway on your initial router. Because they’re on separate subnets, the second router can’t route WWW requests properly. You’ll also need to set this up for any devices on the second subnet, since disabling DHCP on the second router won’t automatically place them in the correct range—it will get an IP from the first router, which falls within the 192.168.1 range.
Getting as close as possible would mean connecting router 1 to a LAN port on router 2 and turning off DHCP and routing. This would make clients obtain an IP address from router 1, effectively converting router 2 into a four-port switch. However, this goes against the goal you’re aiming for. As mentioned earlier, Granular emphasized the need for port-level configuration. There are third-party firmware options available, but I haven’t tested them and there’s no certainty they’ll work exactly as intended. Each port should be handled individually, which is why you’d want to treat LAN Port 1 as a WAN interface with IP 192.168.1.254, route 192.168.2.0/24, and set the default gateway to 192.168.1.1. For LAN Port 2, configure it as a LAN interface with default gateway 192.168.2.1, DHCP pool 192.168.2.2, and DNS servers 1.1.1.1 and 1.0.0.1. LAN Port 3 should also use a LAN interface, default gateway 192.168.2.1, with the same DHCP and DNS settings. If you can’t find a better solution, consider installing third-party firmware and see if others have tried it first.
Third-party firmware isn't compatible with this router. It seems unlikely to have made a big difference since the standard firmware is already very complex and the switch ports are likely too integrated to be treated as separate interfaces. I might need to purchase a new router instead. Appreciate your responses.