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| -rw-r--r-- | netsniff-ng.8 | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/netsniff-ng.8 b/netsniff-ng.8 index 748a390..82c0f78 100644 --- a/netsniff-ng.8 +++ b/netsniff-ng.8 @@ -84,6 +84,31 @@ specify a pcap file as the output device, the file name must have configuration will be written to stdout if the input device is a pcap file, or a pcap file if the input device is a networking device. .PP +.SS -C <id>, --fanout-group <id> +If multiple netsniff-ng instances are being started that all have the same packet +fanout group id, then the ingress network traffic being captured is being +distributed/load-balanced among these group participants. This gives a much better +scaling than running multiple netsniff-ng processes without a fanout group parameter +in parallel, but only with a BPF filter attached as a packet would otherwise need +to be delivered to all such capturing processes, instead of only once to such a +fanout member. Naturally, each fanout member can have its own BPF filters attached. +.PP +.SS -K <hash|lb|cpu|rnd|roll|qm>, --fanout-type <hash|lb|cpu|rnd|roll|qm> +This parameter specifies the fanout discipline, in other words, how the captured +network traffic is dispatched to the fanout group members. Options are to distribute +traffic by the packet hash (\[lq]hash\[rq]), in a round-robin manner (\[lq]lb\[rq]), +by CPU the packet arrived on (\[lq]cpu\[rq]), by random (\[lq]rnd\[rq]), by rolling +over sockets (\[lq]roll\[rq]) which means if one socket's queue is full, we move on +to the next one, or by NIC hardware queue mapping (\[lq]qm\[rq]). +.PP +.SS -L <defrag|roll>, --fanout-opts <defrag|roll> +Defines some auxillary fanout options to be used in addition to a given fanout type. +These options apply to any fanout type. In case of \[lq]defrag\[rq], the kernel is +being told to defragment packets before delivering to user space, and \[lq]roll\[rq] +provides the same roll-over option as the \[lq]roll\[rq] fanout type, so that on any +different fanout type being used (e.g. \[lq]qm\[rq]) the socket may temporarily roll +over to the next fanout group member in case the original one's queue is full. +.PP .SS -f, --filter <bpf-file|expr> Specifies to not dump all traffic, but to filter the network packet haystack. As a filter, either a bpfc(8) compiled file can be passed as a parameter or |