My area has daily power outages that can last several hours. When the power returns, my internet connection is only partially functional: some websites fail to load and messaging apps stop working. The problem affects every device on my network, including computers and phones, and is fixed immediately when I release and renew the IP address. My Belkin RT3200 router is connected to a UPS, but the UPS only lasts about four to five hours while outages can last up to six. What causes this behavior, and is there a way to prevent it?
3 Answers
One possibility is that a computer starts before the router has finished restoring network service and fails to receive a proper IPv4 address. A 169.254.x.x address would point to that specific issue, although the fact that every device is affected makes the router or modem more likely than one computer. Since you have already confirmed that the devices are not receiving 169.254.x.x addresses, check the router's WAN status and DHCP lease after an outage.
A UPS can only delay the problem if it does not last through the entire outage. Before it runs out, shut down the router and modem cleanly, then power them back up after the utility supply is stable. Ideally, use a UPS with enough capacity for the expected outage or configure an automatic shutdown. Also make sure the router's firmware is current, since long WAN interruptions can expose bugs in lease renewal or connection recovery.
The router or the upstream modem may be recovering with a stale or damaged DHCP lease after the long outage. Releasing and renewing the address forces a fresh lease, which explains why that fixes the connection. Check whether the modem is also on the UPS, and restart both devices in order after power returns: modem first, wait until it is fully online, then router. If the problem continues, your internet provider may need to investigate the lease or modem session.
The UPS already powers the router, but it runs out before the longest outages end. Would it help to shut the router down manually before the UPS battery is depleted?
It happens on phones and computers alike, and none of them show a 169.254.x.x address, so it seems to affect the whole network rather than a single device.