Here is the environment - Redhat linux enterprise server 4.0 on a Dell power edge 2900 for web app.
I setup two net devices - eth0 & eth1 on separate vlan for multi-homing using ip_forward. One goes to the outside internet while the other goes to the internal LAN.
Problem - Frequently it appears that eth0 goes to sleep (or dormant) and can not ping it from the network. This is true even from the switch that its connected. After the connection has gone to sleep, I can successfully ping from the server to the network. Once I have pinged from the server to the network, I am able to ping from the network. It has the behavior of going to sleep or powering off. The other device, eth1, works fine, and stays up all the time as it should. The problem is just with eth0. Is there a power management feature in linux for net devices?