Holas, nunca he tenido problemas, bueno algún cortecillo, pero es que ahora ves el system log y es increible.
Sep 20 20:58:52 daemon crit pppd[293]: PPP server detected.
Sep 20 20:58:52 daemon crit pppd[293]: PPP session established.
Sep 20 20:58:55 daemon crit pppd[293]: PPP LCP UP.
Sep 20 20:58:55 daemon crit pppd[293]: Received valid IP address from server. Connection UP.
Y a parte error de dns:
Sep 20 20:53:44 user warn dnsprobe[374]: dns query failed
Sep 20 20:53:46 user warn dnsprobe[374]: dns query failed
Sep 20 20:53:48 user warn dnsprobe[374]: dns query failed
Mis dns son:
Primario --> 87.216.1.65
Secundario --> 80.58.0.97
Tanto en el router como en la configuración de redes.
Como modulación sólo: ADSL2+ Enabled
EDITO
Toda la info completa:
Sep 20 21:25:49 user crit kernel: ADSL link down
Sep 20 21:25:50 daemon crit pppd[293]: Clear IP addresses. Connection DOWN.
Sep 20 21:25:50 daemon crit pppd[293]: Clear IP addresses. PPP connection DOWN.
Sep 20 21:25:57 user crit kernel: ADSL G.994 training
Sep 20 21:26:02 user crit kernel: ADSL G.992 started
Sep 20 21:26:02 user warn dnsprobe[374]: dns query failed
Sep 20 21:26:04 user warn dnsprobe[374]: dns query failed
Sep 20 21:26:06 user warn dnsprobe[374]: dns query failed
Sep 20 21:26:07 user crit kernel: ADSL G.992 channel analysis
Sep 20 21:26:09 user crit kernel: ADSL link up, interleaved, us=863, ds=14304