Network Setup Details
Network Setup Details
Hey everyone, I just moved into a new home and set up my internet setup. The house has CAT5e ports throughout, all leading to a patch panel in one closet. We’re connected via a 1-gigabit fiber line and using AT&T Fiber with their router. The technician installed the modem in the living room, where an Ethernet port goes into the wall and connects to the patch panel. At the panel, there’s an 8-port switch linking all our wired devices. In the router, I changed the DHCP range to 192.168.100.xxx instead of 192.168.1.xxx because my work VPN was conflicting with the same IP range. So far it’s been smooth, but I’m curious if that change might be causing trouble.
The router’s IP is set to 100.254, and the DHCP range is 100.64–100.253. Everything worked well for a while, especially the fast fiber connection. Recently, I noticed my laptop would lose the Ethernet connection after about ten minutes, then switch back to WiFi—especially noticeable since it’s far from the router. I checked other devices on the wired network and they also dropped.
I turned off and re-enabled the patch panel switch, which fixed the issue temporarily. The connection came back online again within ten minutes. I tried swapping in a different 5-port switch, but it didn’t help. My router shows my wired devices with assigned IPs, yet the connection status stays off during outages.
When I checked the settings, I see my devices and their IPs, but the connection is disabled when it drops. If I disconnect the switch and plug it back in, the issue resets. This suggests a possible software configuration problem rather than hardware failure. It seems like when I disconnect the switch and reconnect the router, new IPs are assigned, which might trigger the drop.
I’m not very experienced with networking, so I’m wondering if switching to static IP assignments would help. Would that mean assigning fixed IPs to every device, including those on WiFi? And would this require changing each device’s settings individually?
Your belief about this being a software problem isn't accurate. If all your wired devices stop working simultaneously, it likely points to a hardware wiring concern. If restarting the switch resolves the issue, there are several potential reasons. Follow these steps carefully:
Step 1 - Remove everything from the switch except the router and laptop. This should be done every 10 minutes. Make sure to unplug all cables, even if they aren’t connected. Will this resolve the problem? Does it return?
If the issue persists, move the laptop to a different wired spot in the house. Test only that cable connection to the switch and router. If the problem disappears, identify which device or cable is causing the issue.
Try using both switches together. Connect 2-3 patch panels to each switch and link them. Distribute the longest cables evenly between the switches. This may help pinpoint the source of the problem.
Interestingly, when just my laptop is linked to the switch (and the router too), there are no problems with losing the connection. The same happens with other laptops connected via the switch, as long as only one device is plugged in. Once two devices are connected, the link will intermittently disconnect on both machines, with varying intervals between drops. This suggests the issue lies with the switch itself, possibly due to a malfunction or obstruction causing the drop. Trying alternative ports or shorter cables near the switch didn’t help, as long as at least two devices were connected—whether using the switch or short cables, the problem emerged. Both switches I’m using are unmanaged. The smaller 5-port model is a budget Netgear, while the larger 8-port version is a business-grade model. The port lights seem to show no activity even when a connection exists, but data transfer isn’t happening. When the link cuts, the device IPs on the router appear unavailable.
You have several devices connected, so the only remaining issue is your router. It might be an ARP cache problem or something unusual with the hardware inside, like memory or processor faults. Plugging out the switch can reduce the router’s LAN port usage and often fixes the issue. Next time it happens, try disconnecting the cable linking the router to the switch and then reconnect it. This should work without needing a power cycle. Check if your router has multiple ports—use another one if possible. If you’re using your ISP modem, consider contacting them for a replacement. For your own router, see if the ISP modem can also act as a router; if so, try that option.
After some more testing, I found it was the router/modem at fault. After eliminating the switch entirely and plugging directly into the router, it would still drop connection after a couple minutes. AT&T said everything was fine (of course they would) but sent out a technician anyways and he replaced the router. It's been working great since then. As a side note, I wish AT&T would stop giving consumers ancient routers, I mean the router control panel is the same exact software as the DSL router I had 10 years ago. Anyways, fiber Internet is great.
I’m trying to understand why this thread keeps coming up again. After a short while, the new router the technician installed is behaving the same way. It seems like the situation might repeat every three days as the tech replaces the router, since AT&T doesn’t seem to upgrade their equipment. I’m wondering if there’s another way to fix this. I did some research and found that AT&T offers a gateway/router that combines the ONT and modem/router into one unit. It’s unclear how it functions, because the fiber connection is outside the house and only a standard CAT5e cable is used inside the router. The label says ONT is on the gateway, but it’s not clear if you can run your own device as a modem and router without their system recognizing it. It appears that even with their device in passthrough mode, they need it to be part of the network. If this is indeed a router issue rather than the gateway, maybe switching to a better router with IP passthrough could help. I’m considering buying a new one and possibly upgrading my Wi-Fi range with a modern antenna. But if not, spending around a hundred dollars on something that won’t work seems like a waste. It’s really frustrating, especially since AT&T is such a big company but still provides basic hardware and support. There aren’t many alternatives nearby. Working from home is necessary, but I need a stable internet connection.
It's tough to pinpoint exactly where the problem lies since it's unclear the source. If it's a software issue, it might not be related to the gateway. However, if the issue stems from the switch, it could be due to cabling or connections in the patch panel near the gateway or switches. The gateway shouldn't affect the physical ports on the switch unless they're connected to it. As long as the link from the gateway to the switch remains functional, the gateway is likely handling its tasks correctly.
The AT&T gateway functions as the ONT, handling authorization for network access. Using IP passthrough is typically the optimal choice when you're managing your own router.
It seems the issue continues even when connecting devices directly to the gateway using a short patch cable, and it occurs on all wired connections. The technician who replaced the router mentioned it’s a typical problem with older models from AT&T.