Version: VyOS 2026.09.16-0028-rolling (amd64). Generated config: /run/accel-pppd/pppoe.conf -> lcp-echo-interval=10, lcp-echo-timeout=0, lcp-echo-failure=3.

Summary: The default dead-peer detection on the PPPoE server terminates a session if the subscriber misses LCP echo replies for only 30 seconds. With consumer CPEs/WiFi routers this gap happens routinely, causing spurious disconnections.

Actual: any 30-second gap in a subscriber's replies terminates the session (lcp: no echo reply -> disconnected). In our deployment one account was disconnected five times in one day while the access network was loss-free (queue drops were zero and the other 24 sessions stayed up 34h+).

Expected: documented defaults + guidance (and/or a more tolerant default such as lcp-echo-failure=5), since ppp-options lcp-echo-failure exists but nothing states the effective 30-second dead-peer timeout.

Note: changing service pppoe-server ppp-options lcp-echo-failure applies via systemctl reload-or-restart (accel-ppp SIGUSR1), i.e. without dropping existing sessions -- worth documenting too.