Discussing how to make a router automatically regain its IP address after being disconnected from power.
Discussing how to make a router automatically regain its IP address after being disconnected from power.
Hi everyone, I’m currently using my modem in bridge mode. That setup lets the router manage everything and the modem just supplies the WAN IP. But after a power outage or similar event, the router reverts to its default LAN IP (like 192.168.x.x). I need to either wait for the router to renew its IP (which happens when the DHCP lease ends, around three days) or manually update it in the modem’s software and renew myself. I own a Linksys WRT310N. How can I stop it from using that default IP address? Ideally, it should automatically get the information from the modem during power loss so I don’t have to do anything. It’s convenient when I’m away, but mostly for peace of mind. Should I shorten the lease period? Or disable the LAN IP entirely so it always pulls data from the modem? Thanks, Vitalius.
You have the option to adjust the DHCP lease duration. Just before the lease expires, the devices will communicate; if they're still present, the lease gets renewed. The renewal process should be clear regardless of the original lease length. DHCP also allows you to reserve specific IP addresses, enabling you to assign one to your router on the server side and change it in your router settings to consistently use your preferred reserved IP.
Glenwing, your thoughts are clear. The idea of locking in an IP through the DHCP server isn’t practical because the router receives its address from the modem, which itself gets the IP from the ISP. Since this information changes regularly, reserving a static IP would only be temporary and might cause other issues. I’ll look into adjusting the renewal settings. Regarding lease times, setting a longer lease could affect traffic slightly, but it’s likely minimal unless it becomes excessively long. Your curiosity is good—thank you for asking.
You possess an external IP address and an internal IP address. Each gadget gets its own internal IP from your router's DHCP server. When these are handed to your ISP, they share the same external IP. If you're referring to changing the dynamic IP provided by your ISP, this involves two separate matters. Your external IP from the ISP isn't routed through your modem and isn't managed by DHCP. Your gadgets receive distinct IPs from the connection between your home and the ISP. To clarify, is it your modem, your router, or your devices that are experiencing issues? Also, does your modem function as a standalone device or as part of a modem/router combo (with multiple LAN ports on the back)?
You're dealing with a setup where your modem or router uses a coaxial connection or cable modem/router that's bridged. The process involves converting DSL or coaxial signals into Ethernet frames so you receive an IP from your ISP. If the power to the modem fails, it restarts, but this can take anywhere from 30 seconds to a minute depending on distance and network conditions. Your router may reset faster than the modem can reconnect, which is why you get a temporary private IP. The solution is to release the current IP address and renew it once the connection with your ISP is restored. Let me know if you need more clarity.
Ah, I see where the confusion lies. The IP address used by the router for internet access is what remains constant, not the router's own IP. My modem features a single LAN port on the back, but it can manage multiple connections if that port connects to a switch. I’m familiar with how external and internal IPs work and the distinction between WAN and LAN networks. When the modem isn’t operating in bridge mode, the router displays the default LAN IP address (192.168.2.1) as the source of its internet connection. If the modem switches to bridge mode, the router shows a different IP—75.X.X.X—which is my WAN address. But after a power failure, the router still lists 192.168.2.1 for the internet connection, and renewing it reveals the 75.X.X.X value. That’s the issue. My router relies on the modem’s default IP after an outage instead of recognizing bridge mode and using its own WAN and gateway settings. It seems the DSL modem/router behaves as expected. To address this, I might consider shortening the lease duration to prompt a renewal without disrupting my connection.
It shouldn't be this way; the lease renewal should feel like a continuation rather than an extension. There must be no disruption at all.
It should handle the issue on its own, but if multiple units activate together, that’s when problems arise. A UPS would be a good solution.