I have a few firewalls running on old machines under Debian, and as the network traffic they are handling grows, I realize I have no metric that allows me to decide when the traffic exceeds their hardware capabilities. Just to be clear, these machines are not serving or caching anyting or even NAT-ing --- they are just two PCI network cards and do iptables filtering.
They never register any significant CPU or memory load, but I'm not sure that they would, since the filtering is all in the kernel. I guess I could ping to measure latency and do large file transfers to measure bandwidth, but it would be nice to use some "built-in" metrics. If I did need new hardware, what would I need? CPU? (to handle filter processing?) Memory? (to handle the TCP/IP stack?) NICs? (what distinguises a $20 from $60 10/100 full duplex card?) PCI bus? (does DDR apply to PCI or just memory?) How can I tell which of these is the bottleneck? -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
