Updated on 2024-04-11 GMT+08:00

Viewing a VPC Flow Log

Scenarios

View information about your flow log record.

The capture window is approximately 10 minutes, which indicates that a flow log record will be generated every 10 minutes. After creating a VPC flow log, you need to wait about 10 minutes before you can view the flow log record.

If an ECS is in the stopped state, its flow log records will not be displayed.

Procedure

  1. Log in to the management console.
  1. Click in the upper left corner and choose Network > Virtual Private Cloud.

    The Virtual Private Cloud page is displayed.

  1. In the navigation pane on the left, choose VPC Flow Logs.
  2. Locate the target VPC flow log and click View Log Record in the Operation column to view information about the flow log record in LTS.

    The flow log record is in the following format:

    <version> <project-id> <interface-id> <srcaddr> <dstaddr> <srcport> <dstport> <protocol> <packets> <bytes> <start> <end> <action> <log-status>

    Example 1: The following is an example of a flow log record in which data was recorded during the capture window:

    1 5f67944957444bd6bb4fe3b367de8f3d 1d515d18-1b36-47dc-a983-bd6512aed4bd 192.168.0.154 192.168.3.25 38929 53 17 1 96 1548752136 1548752736 ACCEPT OK

    Value 1 indicates the VPC flow log version. Traffic with a size of 96 bytes to NIC 1d515d18-1b36-47dc-a983-bd6512aed4bd during the past 10 minutes (from 16:55:36 to 17:05:36 on January 29, 2019) was allowed. A data packet was transmitted over the UDP protocol from source IP address 192.168.0.154 and port 38929 to destination IP address 192.168.3.25 and port 53.

    Example 2: The following is an example of a flow log record in which no data was recorded during the capture window:

    1 5f67944957444bd6bb4fe3b367de8f3d 1d515d18-1b36-47dc-a983-bd6512aed4bd - - - - - - - 1431280876 1431280934 - NODATA

    Example 3: The following is an example of a flow log record in which data was skipped during the capture window:

    1 5f67944957444bd6bb4fe3b367de8f3d 1d515d18-1b36-47dc-a983-bd6512aed4bd - - - - - - - 1431280876 1431280934 - SKIPDATA
    Table 1 describes the fields of a flow log record.
    Table 1 Log field description

    Field

    Description

    Example Value

    version

    The VPC flow log version.

    1

    project-id

    The project ID.

    5f67944957444bd6bb4fe3b367de8f3d

    interface-id

    The ID of the NIC for which the traffic is recorded.

    1d515d18-1b36-47dc-a983-bd6512aed4bd

    srcaddr

    The source IP address.

    192.168.0.154

    dstaddr

    The destination IP address.

    192.168.3.25

    srcport

    The source port.

    38929

    dstport

    The destination port.

    53

    protocol

    The Internet Assigned Numbers Authority (IANA) protocol number of the traffic. For details, see Assigned Internet Protocol Numbers.

    17

    packets

    The number of packets transferred during the capture window.

    1

    bytes

    The number of bytes transferred during the capture window.

    96

    start

    The time, in Unix seconds, of the start of the capture window.

    1548752136

    end

    The time, in Unix seconds, of the end of the capture window.

    1548752736

    action

    The action associated with the traffic:

    • ACCEPT: The recorded traffic was allowed by the security groups or network ACLs.
    • REJECT: The recorded traffic was denied by the security groups or network ACLs.

    ACCEPT

    log-status

    The logging status of the VPC flow log:

    • OK: Data is logging normally to the chosen destinations.
    • NODATA: There was no traffic of the Filter setting to or from the NIC during the capture window.
    • SKIPDATA: Some flow log records were skipped during the capture window. This may be caused by an internal capacity constraint or an internal error.

    Example:

    When Filter is set to Accepted traffic, if there is accepted traffic, the value of log-status is OK. If there is no accepted traffic, the value of log-status is NODATA regardless of whether there is rejected traffic. If some accepted traffic is abnormally skipped, the value of log-status is SKIPDATA.

    OK

You can enter a keyword on the log stream details page on the LTS console to search for flow log records.