# PPPoE: LCP echo timeout, no response from peer 192.168.100.1

- **ID:** `networking/pppoe-lcp-echo-timeout`
- **Domain:** networking
- **Category:** protocol_error
- **Verification:** ai_generated
- **Fix Rate:** 72%

## Root Cause

The PPPoE session's Link Control Protocol (LCP) echo requests are not being acknowledged by the remote peer, typically due to a dead access concentrator, a faulty DSL modem, or a misconfigured PPPoE server that has dropped the session silently.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| pppd 2.4.9 | active | — | — |
| pppd 2.5.1 | active | — | — |
| Linux kernel 5.10 | active | — | — |

## Workarounds

1. **killall pppd && pon dsl-provider** (80% success)
   ```
   killall pppd && pon dsl-provider
   ```
2. **reboot modem via web interface or power cycle; then restart pppd: ifdown ppp0 && ifup ppp0** (85% success)
   ```
   reboot modem via web interface or power cycle; then restart pppd: ifdown ppp0 && ifup ppp0
   ```

## Dead Ends

- **Setting lcp-echo-interval to a larger value (e.g., 60 seconds) to reduce timeout frequency.** — This only delays the inevitable disconnection; the underlying peer unresponsiveness remains, and sessions still drop after the longer timeout. (80% fail)
- **Adding 'noecho' option to pppd to stop sending LCP echo requests.** — Hides the failure but leaves the session in a broken state; the PPPoE connection may appear up but cannot pass traffic. (95% fail)