[ale] PPP/DHCP conflict

[John Mills]

ALErs -

This afternoon I noticed that response of my dial-in PPP link had nearly 
stopped while the data-rate log showed that my incoming link was running 
almost 100% saturated even though I couldn't identify any task that 
should have been pulling tons (well, pounds anyway) of incoming traffic. I 
notice a number of log messages to the effect:

Nov 27 07:57:34 muskrat dhcpcd[3140]: eth0: lease expired 342002 seconds 
ago
Nov 27 07:57:34 muskrat dhcpcd[3140]: eth0: broadcasting for a lease
Nov 27 07:57:54 muskrat dhcpcd[3140]: eth0: timed out
Nov 27 07:57:54 muskrat dhcpcd[3140]: eth0: trying to use old lease in 
`/var/lib/dhcpcd/dhcpcd-eth0.info'
Nov 27 07:57:54 muskrat dhcpcd[3140]: eth0: lease expired 342022 seconds 
ago
Nov 27 07:57:54 muskrat dhcpcd[3140]: eth0: broadcasting for a lease
Nov 27 07:58:14 muskrat dhcpcd[3140]: eth0: timed out
Nov 27 07:58:14 muskrat dhcpcd[3140]: eth0: trying to use old lease in 
`/var/lib/dhcpcd/dhcpcd-eth0.info'
Nov 27 07:58:14 muskrat dhcpcd[3140]: eth0: lease expired 342042 seconds 
ago
Nov 27 07:58:14 muskrat dhcpcd[3140]: eth0: broadcasting for a lease
Nov 27 07:58:34 muskrat dhcpcd[3140]: eth0: timed out
Nov 27 07:58:34 muskrat dhcpcd[3140]: eth0: trying to use old lease in 
`/var/lib/dhcpcd/dhcpcd-eth0.info'

I don't know if 'dhcpcd' trying to get an address lease actually accounted 
for the high level of inbound traffic, but it does seem funny that my 
system was trying to obtain a DHCP lease when the connection is over PPP. 
Of course if the system were plugged into a 'live' ethernet LAN, I would 
expect it to obtain an IP address (and a lease) over the wired link; 
that's a good enough reason for the 'dhcpcd' activity I suppose.

At the moment the log messages are posting about every 20 seconds and the 
inbound and outbound data is inermittent and slow (separated peaks of 
approx. 150 B/s). When the link was saturated the outbound rate was 10-100 
B/s while inbound rate was hammered at about 2.9 KB/s. Log messages for 
an activity repeated every 20 seconds doesn't explain that!

The system is running opensuse-11.1 with the KDE desktop. The PPP 
connection is _via_ an external US Robotics modem seen through a 
USB->serial adapter.

Could someone please explain what I'm seeing and how to stop it if it's a 
problem? Likewise suggestions for debugging if I find I'm in the same 
situation again would be helpful.

TIA.
  - Mills