Cflowd
7750 SR OS Router Configuration Guide
Page 601
Operation
depicts the basic operation of the cflowd feature. This sample flow is only used to
describe the basic steps that are performed. It is not intended to specify implementation.
Figure 28: Basic Cflowd Steps
1. As a packet ingresses a port, a decision is made to forward or drop the packet.
2. If the packet is forwarded, it is then decided if the packet should be sampled for cflowd.
3. If a new flow is found, a new entry is added to the cache. If the flow already exists in the
cache, the flow statistics are updated.
4. If a new flow is detected and the maximum number of entries are already in the flow cache, the
earliest expiry entry is removed. The earliest expiry entry/flow is the next flow that will expire
due to the active or inactive timer expiration.
5. If a flow has been inactive for a period of time equal to or greater then the inactive timer
(default 15 seconds), then the entry is removed from the flow cache.
6. If a flow has been active for a period of time equal to or greater than the active timer (default
30 minutes), then the entry is removed from the flow cache.
copy of header sent to cflowd
HEADER
INFORMATION
PROCESSED
AND FLOW CACHE
UPDATED
INGRESS PORT
FORWARD/
DROP ?
SAMPLE?
FINISH FORWARDING
PROCESS AND SEND
TO EGRESS PORT
EGRESS PORT
drop
BIT BUCKET
NEW OR
EXISTING
FLOW
?
existing flow
new
flow
ADD ENTRY
FLOW CACHE
EXPORT
TO
COLLECTOR
UPDATE
ENTRY
Summary of Contents for 7750 SR-OS
Page 10: ...Page 10 7750 SR OS Router Configuration Guide List of Tables...
Page 12: ...Page 12 7750 SR OS Router Configuration Guide List of Figures...
Page 18: ...Getting Started Page 18 7750 SR OS Router Configuration Guide...
Page 108: ...IP Router Command Reference Page 108 7750 SR OS Router Configuration Guide...
Page 200: ...Router Advertisement Commands Page 200 7750 SR OS Router Configuration Guide...
Page 299: ...IP Router Configuration 7750 SR OS Router Configuration Guide Page 299...
Page 300: ...Debug Commands Page 300 7750 SR OS Router Configuration Guide...
Page 348: ...Page 348 7750 SR OS Router Configuration Guide...
Page 388: ...Page 388 7750 SR OS Router Configuration Guide...
Page 442: ...Configuration Notes Page 442 7750 SR OS Router Configuration Guide...
Page 470: ...Filter Management Tasks Page 470 7750 SR OS Router Configuration Guide...
Page 586: ...Configuration Notes Page 586 7750 SR OS Router Configuration Guide...
Page 588: ...OpenFlow Command Reference Page 588 7750 SR OS Router Configuration Guide...
Page 598: ...Show Commands Page 598 7750 SR OS Router Configuration Guide...
Page 608: ...Page 608 7750 SR OS Router Configuration Guide...
Page 646: ...Page 646 7750 SR OS Router Configuration Guide...
Page 660: ...Page 660 7750 SR OS Router Configuration Guide...
Page 666: ...Common CLI Command Descriptions Page 666 7750 SR OS Router Configuration Guide...