PPPoE Error 691 — What It Means & How to Fix It

What Does This Error Mean?

Error 691 means your internet provider rejected your login credentials. Your modem or router tried to authenticate with your ISP's server, but the username or password did not match. This is the internet equivalent of typing the wrong password at a door.

Affected Models

Windows 7
Windows 8
Windows 10
Windows 11
Any DSL or PPPoE broadband connection

Common Causes

Your ISP username or password was entered incorrectly in the router settings
Your ISP has reset or changed your account credentials
Your account has been suspended for non-payment or a billing issue
The ISP's authentication server is temporarily down or overloaded
A modem firmware bug is sending corrupt credentials

How to Fix It

Log into your router or modem's admin page (usually 192.168.1.1 or 192.168.0.1). Go to the WAN or Internet settings and re-enter your ISP username and password carefully.

Check for typos — ISP usernames are often in a format like '[email protected]'.
Contact your ISP and confirm your username and password. Ask them to read it back to you or reset it.

Providers sometimes update credentials after maintenance without notifying customers.
Check your billing status. Log into your ISP's account portal to make sure there are no unpaid bills or service holds.

A suspended account will always reject authentication.
Reboot your modem and router. Unplug both for 30 seconds, then plug the modem in first. Wait two minutes, then plug in the router.

This forces a fresh authentication attempt with the ISP server.
Check for a firmware update for your modem or router. Install it and try connecting again.

Firmware bugs occasionally corrupt stored credentials.

When to Call a Professional

If your credentials are correct and your account is in good standing, call your ISP directly. Ask them to verify that your line is provisioned correctly and that your username and password on their end match what you are using.

Frequently Asked Questions

Does Error 691 mean I have been hacked?

Probably not. It almost always means a wrong username or password — not unauthorized access. If you suspect your ISP account has been compromised, call your ISP immediately and ask them to reset your credentials.

My credentials are correct but I still get Error 691. What now?

If you are 100% sure the credentials are right, the issue is on your ISP's side. Call them and ask them to check whether your line is provisioned correctly. Sometimes an account gets incorrectly flagged in their system.

Can I get Error 691 even with a working internet connection?

Error 691 only appears before a connection is established, so no. If you are online and browsing fine, a different error is likely. Error 691 specifically blocks the PPPoE login step, preventing any connection.