Alcatel-Lucent 7750 SR-OS, Configuration Manual

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Page 610 7750 SR OS Router Configuration Guide
Cflowd Configuration Overview
The 7750 SR OS implementation of cflowd supports the option to analyze traffic flow. The imple-
mentation also supports the use of traffic/access list (ACL) filters to limit the type of traffic that is
analyzed.
Cflowd is not supported on the 7750 SR-1 chassis.
Traffic Sampling
Traffic sampling does not examine all packets received by a router. Command parameters allow
the rate at which traffic is sampled and sent for flow analysis to be modified. The default sampling
rate is every 1000th packet. Excessive sampling over an extended period of time, for example,
more than every 1000th packet, can burden router processing resources.
The following data is maintained for each individual flow in the raw flow cache:
• Source IP address
• Destinations IP address
• Source port
• Destination port
• Input interface
• Output interface
• IP protocol
• TCP flags
• First timestamp (of the first packet in the flow)
• Last timestamp (timestamp of last packet in the flow prior to expiry of the flow)
• Source AS number for peer and origin (taken from BGP)
• Destination AS number for peer and origin (taken from BGP)
• IP next hop
• BGP next hop
• ICMP type and code
• IP version
• Source prefix (from routing)
• Destination prefix (from routing)
• MPLS label stack from label 1 to 6