Configuring Sflow Technology; Overview Of Sflow Technology - Juniper ACX1000 Configuration Manual

CHAPTER 39

Configuring sFlow Technology

Overview of sFlow Technology

Copyright © 2017, Juniper Networks, Inc.
Overview of sFlow Technology on page 1397
Configuring sFlow Technology on page 1399
The sFlow technology is a monitoring technology for high-speed switched or routed
networks. sFlow monitoring technology collects samples of network packets and sends
them in a UDP datagram to a monitoring station called a collector. You can configure
sFlow technology on a device to monitor traffic continuously at wire speed on all interfaces
simultaneously. You must enable sFlow monitoring on each interface individually; you
cannot globally enable sFlow monitoring on all interfaces with a single configuration
statement. Junos OS supports the sFlow technology standard described in RFC 3176,
InMon Corporation's sFlow: A Method for Monitoring Traffic in Switched and Routed
Networks.
An sFlow monitoring system consists of an sFlow agent embedded in the device and a
central data collector, or sFlow analyzer. The sFlow agent performs packet sampling
and gathers interface statistics, and then combines the information into UDP datagrams
that are sent to the sFlow collectors for analysis. The sFlow agent is responsible for
monitoring the network port, sample all incoming packets including control traffic and
traffic arriving on all the ports in the system. The collector can be connected to one of
the data ports or the management interface.
NOTE: sFlow technology is supported only on the ACX5000 line of routers,
other ACX Series routers do not support this technology.
The following sFlow features are supported on the ACX5000 line of routers:
Packet-based sampling—Samples one packet out of a specified number of packets
from an interface enabled for sFlow technology. Only the first 128 bytes of each packet
are sent to the collector. Data collected include the Ethernet, IP, and TCP headers,
along with other application-level headers (if present). Although this type of sampling
might not capture infrequent packet flows, the majority of flows are reported over time,
allowing the collector to generate a reasonably accurate representation of network
activity. You configure packet-based sampling when you specify a sample rate.
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