Available IRQ's?

[brian_e]

Red hat 7.0
IBM pc

I have to eth cards installed ( they were detected at install) I used "cat /proc/pci" to get my IRQ and i/o info, Linux tells me that the info is "I/O at 0xfc80 [0xfc81]" for eth0, and "IRQ 9 I/O at 0xfc00 [0xfc01]" for eth1. They cant be on the same IRQ? right? And is the i/o for eth1 a valid address?

p.s. I'm trying to setup ip masquerading for my two windows on my network, the linux server is conected to a cable modem on NIC and a hub on the other.

Thanks,
brian

[henri]

I read, dunnot know where, that PCI let IRQ sharing take place, maybe your 2 NIC are PCI ones.

[bleg26]

I'm not sure if this is helpful to you or not. But on my freeSCO router both NIC's share the same IRQ. On my windows box I have three devices sharing an IRQ(SCSI, NIC, VID). I have no idea why this happens or why it works, but it does.

[Strike]

Yes, IRQ's can be shared. The way it is done is that different ISRs (Interrupt Service Routines) handle the interrupts, so the interrupt controller can figure out which device signaled the interrupt.