diagnostics for unreliable network

[Peter.Robinson@t-online.de]

Hi Listers,

after a dist-upgrade to sid two weeks ago, my ADSL connection / pppoe intermittently doesnt start. There is no hardware problem as I can get into the network without problems from another OS. 
/etc/init.d/network restart executes without messages, but plog then shows:

anna:/home/peter# plog
Oct 25 07:12:14 localhost pppd[5936]: sendPacket: send: Network is down
Oct 25 07:12:14 localhost pppd[5936]: Exit.
Oct 25 07:12:58 localhost pppd[5954]: The remote system is required to authenticate itself
Oct 25 07:12:58 localhost pppd[5954]: but I couldn't find any suitable secret (password) for it to use to do so.
Oct 25 07:12:58 localhost pppd[5954]: (None of the available passwords would let it use an IP address.)

However, the problem only occurs intermittently. Are there any diagnostic tools that would allow one to narrow down the problem? I am not sure where to start looking?

THanks

Peter