网络流量分析利器-可视化网络-netflow【3】-netflow版本5和版本9区别

发布时间：2020-05-24 00:57:52 作者：cnxhsy
来源：网络阅读：176

网络流量分析利器-可视化网络-netflow【1】-基础原理
网络流量分析利器-可视化网络-netflow【2】-Cisco NetFlow 工作原理介绍及配置
网络流量分析利器-可视化网络-netflow【3】-netflow版本5和版本9区别
网络流量分析利器-可视化网络-netflow【4】-接收器nfdump简介
网络流量分析利器-可视化网络-netflow【5】-linux下数据采集器fprobe
网络流量分析利器-可视化网络-netflow【6】-生产网流量监控架构设计
fprobe参数 -e
fprobe参数 -n -k

注：数据来源于思科官网
Version 5 ：
https://www.cisco.com/c/en/us/td/docs/net_mgmt/netflow_collection_engine/3-6/user/guide/format.html#wp1006108
Version 9 ：
https://www.cisco.com/en/US/technologies/tk648/tk362/technologies_white_paper09186a00800a3db9.html

以下为重点摘要,如格式存在问题，请直接浏览官网

Version 5

Version 5 Header Format

Bytes	Contents	Description
0-1	version	NetFlow export format version number
2-3	count	Number of flows exported in this packet (1-30)
4-7	SysUptime	Current time in milliseconds since the export device booted
8-11	unix_secs	Current count of seconds since 0000 UTC 1970
12-15	unix_nsecs	Residual nanoseconds since 0000 UTC 1970
16-19	flow_sequence	Sequence counter of total flows seen
20	engine_type	Type of flow-switching engine
21	engine_id	Slot number of the flow-switching engine
22-23	sampling_interval	First two bits hold the sampling mode; remaining 14 bits hold value of sampling interval

Version 5 Flow Record Format

Bytes	Contents	Description
0-3	srcaddr	Source IP address
4-7	dstaddr	Destination IP address
8-11	nexthop	IP address of next hop router
12-13	input	SNMP index of input interface
14-15	output	SNMP index of output interface
16-19	dPkts	Packets in the flow
20-23	dOctets	Total number of Layer 3 bytes in the packets of the flow
24-27	First	SysUptime at start of flow
28-31	Last	SysUptime at the time the last packet of the flow was received
32-33	srcport	TCP/UDP source port number or equivalent
34-35	dstport	TCP/UDP destination port number or equivalent
36	pad1	Unused (zero) bytes
37	tcp_flags	Cumulative OR of TCP flags
38	prot	IP protocol type (for example, TCP = 6; UDP = 17)
39	tos	IP type of service (ToS)
40-41	src_as	Autonomous system number of the source, either origin or peer
42-43	dst_as	Autonomous system number of the destination, either origin or peer
44	src_mask	Source address prefix mask bits
45	dst_mask	Destination address prefix mask bits
46-47	pad2	Unused (zero) bytes

Version 9

Version 9 Header Format

Field Name	Value
Version	The version of NetFlow records exported in this packet; for Version 9, this value is 0x0009
Count	Number of FlowSet records (both template and data) contained within this packet
System Uptime	Time in milliseconds since this device was first booted
UNIX Seconds	Seconds since 0000 Coordinated Universal Time (UTC) 1970
Sequence Number	Incremental sequence counter of all export packets sent by this export device; this value is cumulative, and it can be used to identify whether any export packets have been missedNote: This is a change from the NetFlow Version 5 and Version 8 headers, where this number represented "total flows."
Source ID	The Source ID field is a 32-bit value that is used to guarantee uniqueness for all flows exported from a particular device. (The Source ID field is the equivalent of the engine type and engine ID fields found in the NetFlow Version 5 and Version 8 headers). The format of this field is vendor specific. In the Cisco implementation, the first two bytes are reserved for future expansion, and will always be zero. Byte 3 provides uniqueness with respect to the routing engine on the exporting device. Byte 4 provides uniqueness with respect to the particular line card or Versatile Interface Processor on the exporting device. Collector devices should use the combination of the source IP address plus the Source ID field to associate an incoming NetFlow export packet with a unique instance of NetFlow on a particular device.

Version 9 Template FlowSet Field Descriptions

Field Name	Value
FlowSet ID	The FlowSet ID is used to distinguish template records from data records. A template record always has a FlowSet ID in the range of 0-255. Currently, the template record that describes flow fields has a FlowSet ID of zero and the template record that describes option fields (described below) has a FlowSet ID of 1. A data record always has a nonzero FlowSet ID greater than 255.
Length	Length refers to the total length of this FlowSet. Because an individual template FlowSet may contain multiple template IDs (as illustrated above), the length value should be used to determine the position of the next FlowSet record, which could be either a template or a data FlowSet.Length is expressed in Type/Length/Value (TLV) format, meaning that the value includes the bytes used for the FlowSet ID and the length bytes themselves, as well as the combined lengths of all template records included in this FlowSet.
Template ID	As a router generates different template FlowSets to match the type of NetFlow data it will be exporting, each template is given a unique ID. This uniqueness is local to the router that generated the template ID.Templates that define data record formats begin numbering at 256 since 0-255 are reserved for FlowSet IDs.
Field Count	This field gives the number of fields in this template record. Because a template FlowSet may contain multiple template records, this field allows the parser to determine the end of the current template record and the start of the next.
Field Type	This numeric value represents the type of the field. The possible values of the field type are vendor specific. Cisco supplied values are consistent across all platforms that support NetFlow Version 9.At the time of the initial release of the NetFlow Version 9 code (and after any subsequent changes that could add new field-type definitions), Cisco provides a file that defines the known field types and their lengths.The currently defined field types are detailed in Table 6.
Field Length	This number gives the length of the above-defined field, in bytes.