Format Of Netflow Export Datagram - Extreme Networks PoS Installation And User Manual

Table 3-12: NetFlow Version 1 Record Format (continued)
Field Name
dPkts
dOctets
First
Last
srcport
dstport
pad
prot
tos
tcp_flags
pad
Flow records are grouped together into UDP datagrams for export to a flow-collector
device. A NetFlow Version 1 export datagram can contain up to 25 flow records.
Figure 3-9 shows the format of the export datagram; Table 3-13 describes the export
datagram header.
octets 16
Header
Figure 3-9: Format of NetFlow export datagram
Packet Over SONET Module Installation and User Guide
Octets Field Description
4 Number of packets sent in this flow
4 Number of octets sent in this flow
4 SysUptime when flow record was created
4 SysUptime at most-recent, or last packet of flow
2 Source port number, valid only for TCP and UDP flows
2 Destination port number, valid only for TCP and UDP flows
2 Unused field
1 Number identifying the IP protocol; for example, 6=TCP and
17=UDP
1 IP Type-of-Service (TOS) field value from initial packet that
caused this flow record to be created
1 Cumulative OR of TCP flags field, valid only when prot=6
11 Unused field
52
Flow record 1 Flow record 2
Configuring and Monitoring Flow Statistics
52
. . .
52
Flow record n
PoS_023
3-61