Specify the denominator (number) of the ratio that is the sample rate in sFlow traffic monitoring. For example, to configure a sample rate of 1 in 1000 packets, you specify a number of 1000. Things such as the community string, IP address of the switch and preferred sampling rate will need to be adjusted. I’ve included the four OID that will need to be run against every port on your switch in order to enable sFlow. SNMP GET for sFlow sample rate: Packet Sampling Basics. Peter Phaal and Sonia Panchen, sFlow.org Overview. Packet-based sampling schemes are widely used to characterize network traffic. Packet sampling uses randomness in the sampling process to prevents synchronization with any periodic patterns in the traffic. Mar 24, 2015 · When routers use sampling for NetFlow generation, an interesting thing happens. The sampling is done on a packet-count level, so a 1:512 sampling rate will grab roughly every 512th packet to update the flow state tables. This is great for reducing CPU load. But it is not so great at reducing flow update rate.
HP sFlow switches . Both XRMON and sFlow are sampling technologies. The following article includes rules of thumb that provide a good starting point for setting the sampling rates: Sampling rates . You mention that you are also interested in monitoring servers. The sFlow standard was recently extended to include server monitoring. The number of packets in the expired flow exceeds the sampling rate: If in a interval of X – where X is a value in the range of 8000-16000 (inclusive), a flow has a greater number of packets than the value configured for the sampling-rate, the flow is sampled (selected) and then exported.
Monitoring System Statistics and Network Traffic with sFlow. sFlow is a monitoring protocol that samples network packets, application operations, and system counters. sFlow collects both interface counters and sampled 5-tuple packet information, enabling you to monitor your network traffic as well as your switch state and performance metrics. The recommended sample rate for sFlow is 8192 which is the default sample rate. Additional notes Higher numbers mean fewer samples and longer times between samples.
The following configuration enables sFlow monitoring of all interfaces on a Juniper EX3200 switch, sampling packets at 1-in-500, polling counters every 30 seconds and sending the sFlow to an analyzer (10.0.0.50) on UDP port 6343 (the default sFlow port). It is a technology that is based on statistical sampling. You can configure sFlow technology to continuously monitor traffic at wire speed on all interfaces simultaneously. Junos OS fully supports the sFlow standard described in RFC 3176, InMon Corporation's sFlow: A Method for Monitoring Traffic in Switched and Routed Networks.
The following configuration enables sFlow monitoring of all interfaces on a Juniper EX3200 switch, sampling packets at 1-in-500, polling counters every 30 seconds and sending the sFlow to an analyzer (10.0.0.50) on UDP port 6343 (the default sFlow port). PTX Series,EX Series,QFX Series,OCX Series,MX Series. Benefits of sFlow Technology, Sampling Mechanism and Architecture of sFlow Technology, Adaptive Sampling, How Adaptive Sampling Works, Adaptive Sampling Fallback, Adaptive Sampling Limitations, sFlow Agent Address Assignment, sFlow Limitations on Routers, sFlow Limitations on Switches
sFlow agents can be added to any type of FortiGate interface. sFlow isn't supported on some virtual interfaces such as VDOM link, IPsec, gre, and ssl.root. For more information on sFlow, Collector software and sFlow MIBs, visit www.sflow.org. Configuration. sFlow configuration is available only from the CLI. sFlow.org is an international, multi-vendor, and end-user forum. It promotes the benefits of sFlow sampling technology for monitoring and managing traffic in complex networks, and drives the widespread adoption of sFlow by end users, network equipment vendors, and software application developers. Mar 24, 2015 · When routers use sampling for NetFlow generation, an interesting thing happens. The sampling is done on a packet-count level, so a 1:512 sampling rate will grab roughly every 512th packet to update the flow state tables. This is great for reducing CPU load. But it is not so great at reducing flow update rate. Jul 28, 2009 · The following commands configure an Extreme Networks switch (10.0.0.246), sampling packets at 1-in-512, polling counters every 30 seconds and sending the sFlow to an analyzer (10.0.0.50) over UDP using the default sFlow port (6343): enable sflow configure sflow agent 10.0.0.246 configure sflow collector 10.0.0.50 port 6343 configure sflow sample-rate 512 configure sflow poll-interval 30 enable sflow backoff-threshold configure sflow backoff-threshold 100 enable sflow ports all
Jul 10, 2014 · Configuring j-flow Export on Juniper SRX Devices Using Junos 12.1×46. This document focuses on configuring Juniper J Series and SRX Series devices for J-Flow v9, which is based on the RFC3954 (IPFIX) flow export standard (via UDP) and as such is consumable by any IPFIX-capable flow collector, including FlowTraq.