Network issue due to IP conflicts.
Network issue due to IP conflicts.
Hello Friends, Could someone more experienced please elaborate on the problem and attempted solution? I'm still troubleshooting and could use some insight to figure this out and confirm what I need to do to fix it. Problem: We have a large network for a household, and for years now, I've been experiencing network dropouts almost daily, sometimes every 8 to 12 hours. The entire network crashes and I can see that my routers/extenders keep attempting to connect, but never do. They just end up being on a loop of crashing and reconnecting. This is usually remedied by switching off my main router and network switch, waiting a while, then switching them back on. Things would be stable again until they aren't. We would take turns. It's a part of our lives by now. Attempted solution: Set the DHCP & NAT settings to "manual IP" as can be seen in the attached screenshot. Tried many things before that didn’t work. I'm at a point now where it's looking like it might be an ip address conflict? The timeline makes sense? I also read something about IP addresses expiring after a while once they are "leased out". Additionally, I managed to grab two screenshots showing two routers having the same address? Not sure how accurate this is though. Doubts: Is there anything more to it or is the solution I applied correct? I will monitor and report back over the next few days if there was a dropout or not. Does the solution imply that from now on, every device that stays on the network will never get assigned a new address unless they disconnect/reconnect? Effectively stopping the whole "leasing" process and the ip address conflict? Based on the settings I've set for the starting and ending IP, does this mean that there is a limit to the number of devices that can join the network? Is there a way to increase the limit if needed? There's more settings for port reservations, but that's only if I want a certain device - outside of the routers - to always have the same address even if they disconnect and reconnect? Basically this has nothing to do with routers having an ip address conflict and crashing the network, correct? Thanks! Let me know if I can provide more info.
All Eero gadgets were involved. I posted the images to illustrate duplicate IP addresses. However, I'm uncertain about the accuracy of those screenshots. The Eero app refreshes data after you inspect a device, and the image was captured at the moment of the drop. It's hard to verify if the problem stems from the router's IP expiring and generating a new duplicate, which might disrupt the network. DHCP settings were set to automatic before; I thought the system would handle it better. You can review the network map using this link. Generally, the ISP ONT serves as the central router, sending signals to the main network switch. From there, the switch distributes the signal through CAT6 cables to various routers spread across locations. Exceptions exist for wireless extenders, and there are two additional switches in separate areas. I noticed the main switch was suggested by Eero, but I'm not sure if they endorse the other two. They lack QoS features (like the D-Link 5 Port Gigabit Unmanaged Metal Desktop Switch). The issue persisted even with the recommended switch. I tested several alternatives, but none resolved the problem. With around 80 to 100 devices connected—including smart devices and lights—the network is quite busy. More users joining could worsen the situation. Let me know if this clarifies anything!
Usually yes, an IP address lease can end, but assigning a new IP should work fine. Keep in mind you should have only one DHCP server; too many devices sharing IPs may cause conflicts. The DHCP server is responsible for distributing IP addresses, and the limit is often around 254 addresses. Switching the starting IP can boost the number your router can provide.
Is the ISP device merely a media converter or does it act as a fibre gateway? That’s quite a lot of confusion! Are all these devices located in one house? Are they all operating in their standard configuration? If yes, you’ve likely set up multiple NAT layers, which can lead to LAN IP conflicts. Think about running everything downstream from the “gateway Eero” in bridge mode. Can you adjust the starting/ending IPs manually through the LAN settings?
I might not grasp all of this completely, so please give me a chance to explain clearly. The ONT includes a bundled package from the ISP and you can't change it. You receive TV, a landline, and internet via fiber. There are several families, but they’re built with solid construction so there’s no alternative way to send signals without extra routers. This seems to match what we’ve been having lol. I think that’s the case. I’m not entirely sure about the meaning of “default mode” here. In the Eero app, network settings start with your “internet settings.” There’s not much you can adjust except toggling IPv6. Then there’s the WAN type—three options: DHCP default, static IP, or PPPoE. I can’t really change much because it’s set by the ISP, and I have to pick PPPoE for the gateway Eero connected to the ONT. Next comes “network services” where you can adjust:
- DHCP & NAT: Auto (default), Manual IP (current choice shown in the screenshot), or Bridge mode (rarely used).
- Reservation & Port forwarding (only if I need specific IPs for certain devices besides routers).
- DNS (unrelated here).
- UPnP (also unrelated).
I’ll try these changes if the current ones aren’t working. So far, it’s been over 12 hours without a dropout on Manual IP. If you check the screenshot from my first post, once you pick Manual IP, there are several options to adjust. The IP address prefix can be set as 192.168.0.0 through 172.16.0.0, and then you enter details under Lease Range, Subnet IP, Subnet Mask, Starting IP, and Ending IP.
It might be that they used fixed IP addresses. You can't assign a static IP inside the DHCP pool or you risk conflicts. In the past, before routers let you reserve IPs in the DHCP server, you had to manually configure them. For instance, starting at 100 would give you a range like 192.168.1.2 through 192.168.1.99 for static use. Here are some examples I can provide. My Plex server runs on Linux and I can connect via SSH to apply updates and manage tasks. My NAS also has a fixed address, allowing me to reach its interface. Knowing these IPs simplifies the process.
Reported that there have been no disconnections since configuring DHCP and NAT to manual IP addresses, as shown in the original screenshot. It hasn't been this long without any interruptions. Seems the issue has been resolved. Will wait another week to confirm everything stays stable. UPDATE: Dropouts began roughly a week later. Edited May 20, 2023 by malawar