Unusual Link Problem
Unusual Link Problem
Last week we experienced an internet disruption with CenturyLink. While diagnosing, before the technician confirmed the local issue, she reset my modem to its default settings (pressing the reset button). Since then, my computer—one of three hardwired devices connected to the modem—continues to lose internet access. When this occurs, I can still connect to the modem interface, which excludes a faulty onboard NIC. All wireless devices remain operational. My work PC, also hardwired, isn’t affected. I’ve reviewed all available settings; everything is restored to my personal defaults (non-default password, custom network name and password). The only discrepancy was a failed built-in diagnostics test labeled "DNS #2." It currently passed. I’m unsure if this is the root cause or another factor. If it is, I need guidance on next steps. I’ve attempted several fixes: a full reboot of both router and computer, releasing and renewing my network connection, trying static IP settings, but Windows 10 refused to save changes. I have some networking knowledge but limited experience. I’m comfortable troubleshooting but not confident in resolving this alone. Any recommendations? Eric the Grey
On this device, switching from Dynamic DNS to Static in WAN settings seems correct. I attempted this and lost internet instantly. Restoring didn’t immediately resolve the issue; it took time for the connection to return. I repeated the process three times with the same outcome each time. Noted something unusual about the modem’s behavior—its Cyber Security mode. Disabling it (despite the unclear warning) seems to restore a lost connection. Re-enabling it doesn’t automatically cause another drop. I’m turning it off now to check if anything changes. Edit: Updating the DNS entry didn’t affect my access even after changing the IP addresses. Part of me thinks this might be linked to my Plex server, which runs locally on my computer since I don’t have a dedicated server. Eric the Grey
It's odd. Contact the ISP tech support; they might swap the modem. Avoid fixing it yourself—they're unreliable. Just disconnect it, reach out, and mention the internet isn't functioning.
Dynamic DNS is enabled to ensure reliable connectivity. It’s not a default unless you’re running a service that requires it. You usually don’t need it unless you’re hosting something. The setup clearly separates DNS configuration from DDNS, so you should adjust the DNS settings yourself. Your ISP typically provides DNS servers automatically, which is why I recommended changing them—they might be subpar. If the primary DNS fails, the secondary one will still work, but the main one remains the preferred choice for your devices.
I'm thinking about this. I want to skip another charge on my statement, but I believe it's comparable in cost. I need to verify that. The DNS server indicates Dynamic or Static, though I suspect I'm viewing the wrong option, and I don't see any other place to adjust the settings. The default is active (refer to image "DNS" attached). Disabling it would let me modify it (see image "DNS 2" attached). The only remaining option is under LAN, which just lets me enter a server name and IP address (see image "DNS Name" attached). ipconfig /all: Warning Connection-specific DNS Suffix . : Realtek PCIe GbE Family Controller #3 Physical Address. . . . . . . . . : 18-C0-4D-20-58-4B DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::f4a3:d018:e0f1:b063%11(Preferred) IPv4 Address. . . . . . . . . . : 192.168.0.3(Preferred) Subnet Mask . . . . . . . . . . : 255.255.255.0 Lease Obtained. . . . . . . . . . : Tuesday, March 21, 2023 8:45:15 AM Lease Expires . . . . . . . . . : Thursday, March 23, 2023 8:45:16 AM Default Gateway . . . . . . . . . : 192.168.0.1 DHCP Server . . . . . . . . . : 192.168.0.1 DHCPv6 IAID . . . . . . . . . : 202948685 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-26-71-49-08-18-C0-4D-20-58-4B DNS Servers . . . . . . . . . : 192.168.0.1 205.171.3.25 NetBIOS over Tcpip. . . . . . . . : Enabled
Yeah, their GUI is confusing... There is a Tab called "Dynamic DNS" just under "WAN Settings" in the top left corner. That's the stuff that usually is OFF by default, unless you need it. The DNS settings are in your second picture, change those two IPs from 205.171.3.25 and 205.171.2.25 to something like 1.1.1.1 and 9.9.9.9 and save it. Your third picture, under "LAN settings" leave those alone (disabled) Now for the PC, it's getting it's IP automatically, so after you change your DNS IP on your router, issue "ipconfig /release" and "ipconfig /renew" on your PC... then your DNS settings should change and you should no longer use the ISP DNS Might need a reboot.
The router is intended to share its DHCP settings for DNS, but both the server and the PC aren't working. Your PC is falling back to its default gateway as a DNS resolver because other options aren't available. Your router should still have properly configured DNS servers. Check your DHCP configuration—there might be an issue there.
My DHCP page displays the information you see. Switching from Default Servers to Manual Servers shows the second screenshot. The primary DNS type is set correctly in the WAN Settings, and everything else appears normal to me.