NIC Sleeps after some idle time

My home machine has two NICs.  Eth0 has ip address via DHCP (ADSL). Eth1 has static ip.  Everything works, except that eth0 seems to "fall a sleep" once in a while.  Once it is in this mode, I will not be able to ping, telnet, ...etc from outside, my internal network (via eth1) has never had any problem
getting out. Once eth0 falls asleep I would have to try later and it will somehow wake up by itself (after about 10-30 minutes).  APM is turned off on the BIOS (I heard claims it might be the problem, but I question why eth1 never falls asleep)
I also noticed that if I have my wife ping an outside site from my home machine, eth0 will come back alive right away.  So my only solution now is this is to have the
home machine ping an external site (ex.
every 1 minute.  With the ping on, I can alawys get to
my home machine from work.  I have few peopel on
the web that have the same problem and none could
figure out what the story is.  BTW, under NT, the problem goes away.
Who is Participating?
jlevieConnect With a Mentor Commented:
It's not Linux that's going to sleep, it's the ADSL implementation. Most likely there's a router upstream that has a short arp timeout. If the router doesn't see data from your MAC address often enough it drops the arp entry from it's tables and then won't know where your system is to route data to it. NT is very chatty on its ethernet connections, pumping out a packet every few minutes, which is why it never timed out. Your provider has probably set their system up this way to discourage people from running servers on their DSL lines, and the Terms & Conditions of your service will probably state words to that affect.

The only workaround is, as you've discovered, to routinely send data out. It shouldn't matter if you ping a valid address or not. The act of pushing out a packet ought to do the trick.
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