Complex powerline conditions Situation on the power lines
Complex powerline conditions Situation on the power lines
Hello there, fellow community members. Your support has been valuable before, and I’m sure you’ll find a solution soon. I’m dealing with a fairly complex setup. My home is two floors high, and I’m planning to set up a server room on the second floor. The servers will manage storage, routing, and computing tasks. The routing challenge is what’s keeping me stuck. I have a repurposed Dell Optiplex 330 as my main router—equipped with both an onboard NIC and a PCIe NIC. One port handles output, the other input. So far it works fine. However, connecting this router to the second floor requires linking it to the modem and ISP modem via Ethernet. I’m considering power line adapters, but realized I’d need two for stability. With a budget of around $70 for these adapters, I can only afford one. I’m wondering if I can route both input and output through a single power line cable—possibly using pfSense or Debian as the OS? Thanks in advance for your help!
What kind of ISP connection do you have? VSDL, ASDL+ or Cable/fiber? With a phone line, you can use an Ethernet cable. If that's not possible, why not run an Ethernet cable yourself? I wouldn't suggest using a powerline adapter for your router—it's not the best option.
What you aim to accomplish is commonly referred to as a router on a stick setup. Ideally, using VLANs would be the best approach, but it would need a managed switch at the modem to manage traffic splitting. You could also assign distinct network addresses for modem and router traffic—though VLANs are necessary anyway. Be mindful of exposing the modem's network segment safely, especially if it holds your WAN address. You also mention servers on the second floor, meaning you’ll likely need separate gateway addresses for clients on different floors. This can be handled easily, and a DMZ could serve as a distinct network.
Assuming you can choose your router-modem connection as a custom network (the simplest option), proceed like this:
- Onboard card targets second-floor devices (eth0) with IP 192.168.2.254/24
- Modem gets eth1:1 at 192.168.3.254/30
- First-floor clients use eth1 and eth1:1 at 192.168.1.254/24
This ensures only eth1:1 can communicate directly, avoiding unnecessary layer 2 issues.
Second-floor devices are in 192.168.2.0/24 with gateway .254
First-floor devices sit in 192.168.1.0/24 with gateway .254
If using Debian, you can configure iptables to treat eth0, eth1, and eth1:1 as separate interfaces, connecting both LANs to the WAN and allowing traffic between them.
For security, consider alternatives like VLANs or a dedicated gateway if possible.
The main challenges are handling PPPD or similar tools on the router and ensuring proper firewall rules for cross-LAN communication.
If you must use pppd or similar on the modem, remember to keep the 192.168.3.252 network available for management access.
This setup is feasible even without VLANs, but extra caution is needed around exposure and security policies.
A smart or managed switch might handle this situation. You'd typically route traffic from the modem port through a single NIC in the router and another through a separate NIC, assigning each to a different VLAN. The router would then forward that traffic without tags across ports. You could bridge the second NIC to the LAN VLAN to connect other devices nearby. I’m not very experienced with VLANs, so I don’t have the exact details. Keep in mind that using this setup means the router manages traffic between different areas, which could strain its processing power if large transfers occur. A dedicated second managed switch would likely cost more, possibly approaching the price of two separate powerline systems. It seems impractical to run multiple powerline networks on the same wiring, so this might be the only feasible choice.
It’s a complex topic that many take for granted. My perspective is that if you can use an ASIC to manage your packets as desired, go ahead. But if you require a particular firmware version for specific tasks, it’s likely you’re relying on software instead. A more accurate approach would be to say, “Don’t rely on CPU bridging unless necessary.” Even with abundant CPU resources here, sticking to software remains the safer choice. In situations like this, physical constraints matter—having a managed switch at each end that handles inter-VLAN routing could balance performance and simplify management. That way, you avoid bottlenecks or unnecessary costs.
By the way, I usually achieve better results with custom-built gear or repurposed hardware than with off-the-shelf commercial routers, since I often need to handle unusual configurations.