Internet & modems

PPPoE authentication failed error

This error means the router couldn't log into your internet provider's network using the username and password (PPPoE credentials) it has stored, which is common with DSL and some fiber setups and is usually fixed by re-entering the correct credentials.

Difficulty
Moderate
Time
15–30 minutes
DIY cost
$0
Pro cost
$0–$100

Symptoms

  • Router's status page shows 'PPPoE authentication failed' or similar
  • Internet light stays off or shows a connecting/disconnected state
  • Error appeared after a router replacement or factory reset
  • Provider specifically uses username/password login for internet, common with DSL

Likely causes

  • CommonIncorrect or outdated PPPoE username or password entered in the routerThese credentials are provided by your ISP and must be entered exactly, often as a full email-style username.
  • CommonRouter replaced or reset without re-entering the PPPoE credentialsThese settings don't come from the ISP automatically in most consumer routers; they must be manually configured.
  • PossibleISP-side account issue affecting login, such as a service change or billing holdOccasionally the credentials are correct but the account itself is temporarily restricted.
  • Less commonOnly one device can be authenticated with these credentials at a timeIf an old router or ONT still holds an active session, a new one may be rejected until the old session times out.

What to do

  1. Locate your PPPoE username and password from your ISP's welcome documentation, account portal, or by calling support.
  2. Log into the router's admin page and find the internet/WAN connection type setting, confirming it's set to PPPoE.
  3. Carefully re-enter the username and password exactly as provided, paying attention to case sensitivity and any '@' domain suffix often included in the username.
  4. Save the settings and allow the router a minute or two to attempt authentication.
  5. If authentication still fails, restart the modem/ONT as well as the router, since a stale session on the line can block a new login attempt.
  6. Confirm with your ISP that your account is active and that the specific credentials are current, since they can occasionally be reset by the provider.
  7. If working with a newly installed line, wait a short period after installation, since PPPoE accounts sometimes take a little time to fully activate on the provider's end.

Tools and parts

  • Access to router's admin page
  • PPPoE credentials from ISP

When to call a pro

If correct credentials still fail to authenticate, contact your ISP, since they can verify or reset the account-side authentication settings.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.