The Linux IP accounting feature is very closely related to the Linux
firewall software. The places you want to collect
accounting data are the same places that you would be interested in
performing firewall filtering: into and out of a network host, and in the
software that does the routing of datagrams. If you haven't read the section
on firewalls, now is probably a good time to do so, as we will be using some of
the concepts described in Chapter 9.
To activate the Linux IP accounting feature, you should first see if your
Linux kernel is configured for it. Check to see if the /proc/net/ip_acct file exists. If it does, your kernel already supports IP accounting. If it doesn't, you must build a new kernel, ensuring that you answer “Y” to the options in 2.0 and 2.2 series kernels:
Networking options --->
[*] Network firewalls
[*] TCP/IP networking
...
[*] IP: accounting |
or in 2.4 series kernels:
Networking options --->
[*] Network packet filtering (replaces ipchains) |
