diff options
Diffstat (limited to 'README.bsd')
| -rw-r--r-- | README.bsd | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/README.bsd b/README.bsd new file mode 100644 index 0000000000..cd6527c57b --- /dev/null +++ b/README.bsd @@ -0,0 +1,32 @@ +$Id: README.bsd,v 1.1 2000/02/19 21:54:07 guy Exp $ + +In order to capture packets (with Ethereal/Tethereal, tcpdump, or any +other packet capture program) on a Linux system, your kernel must have +the Berkeley packet Filter mechanism enabled. On some BSDs (recent +versions of FreeBSD, for example), it's enabled by default in the +generic kernel; it's not enabled by default in older FreeBSD kernels, +and might not be enabled by default in other kernels. + +The entry in the FreeBSD 3.4 i386 GENERIC configuration file for it is: + + # The `bpfilter' pseudo-device enables the Berkeley Packet Filter. + # Be aware of the administrative consequences of enabling this! + # The number of devices determines the maximum number of + # simultaneous BPF clients programs runnable. + pseudo-device bpfilter 1 #Berkeley packet filter + +To enable BPF, add "pseudo-device" line such as the last line there to +your configuration file, re-run "config", rebuild the kernel, install +the new kernel, and reboot. + +Note that some daemons, or other applications, may be BPF clients, i.e. +may use the BPF mechanism to see link-layer traffic coming into the +machine and send link-layer traffic from the machine; for example, if +the number in the "pseudo-device bpfilter" line is 1, and such a daemon +or application is running, a packet-capture program will not be able to +do packet capture, as the one and only BPF device will already be in +use. You may therefore need to increase the number of BPF devices, by +increasing the number in the "pseudo-device bpfilter" line, re-running +"config", rebuilding the kernel, installing the new kernel, and +rebooting. + |