From 3d2136f5c578cd282ca0190f4698015304cbac05 Mon Sep 17 00:00:00 2001 From: Stephen Wadeley Date: Tue, 14 May 2013 23:54:17 +0200 Subject: man: improvements to language and markup for ifpps.8 Signed-off-by: Stephen Wadeley Signed-off-by: Daniel Borkmann --- ifpps.8 | 81 ++++++++++++++++++++++++++++++++--------------------------------- 1 file changed, 40 insertions(+), 41 deletions(-) diff --git a/ifpps.8 b/ifpps.8 index 8f802e9..6598d14 100644 --- a/ifpps.8 +++ b/ifpps.8 @@ -1,22 +1,22 @@ .\" netsniff-ng - the packet sniffing beast .\" Copyright 2013 Daniel Borkmann. .\" Subject to the GPL, version 2. - +.PP .TH IFPPS 8 "03 March 2013" "Linux" "netsniff-ng toolkit" .SH NAME ifpps \- top-like networking and system statistics - +.PP .SH SYNOPSIS - +.PP \fB ifpps\fR { [\fIoptions\fR] | [\fIdevice\fR] } - +.PP .SH DESCRIPTION - +.PP ifpps is a small utility which periodically provides top-like networking and system statistics from the kernel. ifpps gathers its data directly from procfs files and does not apply any user space monitoring libraries -which could falsify statistics on high load. - +which could falsify statistics under high load. +.PP For instance, consider the following scenario: two directly connected Linux machines, each with an Intel Core 2 Quad Q6600 2.40GHz CPUs, 4 GB RAM, and an Intel 82566DC-2 Gigabit Ethernet NIC, are used for performance @@ -24,74 +24,73 @@ evaluation. One machine generates 64 byte network packets by using the kernel space packet generator, pktgen, with a maximum possible packet rate. The other machine displays statistics about incoming network packets by using i) iptraf(8) and ii) ifpps. - +.PP iptraf which incorporates pcap(3) shows an average packet rate of 246,000 pps, while on the other hand, ifpps shows an average packet rate of 1,378,000 pps. Hence, due to packet copies and deferring statistical -calculations to user space, a measurement error of approx. 460 per cent -occurs. Tools like iptraf might display much more information such as -TCP per flow statistics (therefore the use of the pcap library), which -is not implemented in ifpps, because overall networking statistics is -our focus; statistics, which are also fairly reliable under high packet -load. - +calculations into user space, a measurement error of approximately 460 per cent +occurs. Tools like iptraf might display much more information, such as +TCP per flow statistics (hence the use of the pcap library), that is not +possible with ifpps, because overall networking statistics are our focus; +statistics, which are also reliable under high packet load. +.PP .SH OPTIONS - +.PP .SS -d , --dev -Networking device to fetch statistics from, e.g. eth0, wlan0. - +Networking device to fetch statistics from, for example, eth0, wlan0. +.PP .SS -t