Skip to content

Contact sales

By filling out this form and clicking submit, you acknowledge our privacy policy.
  • Labs icon Lab
  • A Cloud Guru
Google Cloud Platform icon

Work with AWS VPC Flow Logs for Network Monitoring

Monitoring network traffic is a critical component of security best practices to meet compliance requirements, investigate security incidents, track key metrics, and configure automated notifications. AWS VPC Flow Logs captures information about the IP traffic going to and from network interfaces in your VPC. In this hands-on lab, we will set up and use VPC Flow Logs published to Amazon CloudWatch, create custom metrics and alerts based on the CloudWatch logs to understand trends and receive notifications for potential security issues, and use Amazon Athena to query and analyze VPC flow logs stored in S3.

Google Cloud Platform icon

Path Info

Clock icon Advanced
Clock icon 1h 30m
Clock icon Sep 03, 2020

Contact sales

By filling out this form and clicking submit, you acknowledge our privacy policy.

Table of Contents

  1. Challenge

    Create a CloudWatch Log Group and a VPC Flow Log to CloudWatch

    1. Create a VPC flow log to S3, setting the Maximum aggregation interval to 1 minute and the S3 bucket ARN to the VPC Flow Logs S3 Bucket ARN found in the lab credentials or obtained via S3.
    2. Create a CloudWatch log group. Name it VPCFlowLogs.
    3. Create a VPC flow log to CloudWatch using the IAM role provided for the lab (the one with DeliverVPCFlowLogsRole in the name) and the CloudWatch log group you created.
    4. Generate some traffic for the flow logs.
  2. Challenge

    Create CloudWatch Filters and Alerts

    1. Create a CloudWatch log metric filter named dest-port-22-rejects. For the Metric namespace, use VPC Flow Logs; for Metric name, use SSH Rejects; and for Metric value, enter 1.

      • Use the below filter pattern:

        [version, account, eni, source, destination, srcport, destport="22", protocol="6", packets, bytes, windowstart, windowend, action="REJECT", flowlogstatus]
      • Use the following for the log data:

        2 086112738802 eni-0d5d75b41f9befe9e 39611 22 6 1 40 1563108188 1563108227 REJECT OK
        2 086112738802 eni-0d5d75b41f9befe9e 42227 22 6 1 44 1563109030 1563109067 REJECT OK
        2 086112738802 eni-0d5d75b41f9befe9e 52417 22 6 24 4065 1563191069 1563191121 ACCEPT OK
        2 086112738802 eni-0d5d75b41f9befe9e 39611 80 6 1 40 1563108188 1563108227 REJECT OK
    2. Create an alarm called SSH-rejects based on the metric filter.

    Note: There may be a New Console Experience button in the top left of the CloudWatch console. These instructions are designed for this new layout, so ensure this is toggled on if it is present.

  3. Challenge

    Use CloudWatch Logs Insights

    Apply the Top 20 source IP addresses with highest number of rejected requests sample query.

  4. Challenge

    Analyze VPC Flow Logs Data in Athena

    1. Create the Athena table:

      CREATE EXTERNAL TABLE IF NOT EXISTS default.vpc_flow_logs (
        version int,
        account string,
        interfaceid string,
        sourceaddress string,
        destinationaddress string,
        sourceport int,
        destinationport int,
        protocol int,
        numpackets int,
        numbytes bigint,
        starttime int,
        endtime int,
        action string,
        logstatus string
      PARTITIONED BY (dt string)
      LOCATION 's3://{your_log_bucket}/AWSLogs/{account_id}/vpcflowlogs/us-east-1/'
      TBLPROPERTIES ("skip.header.line.count"="1");
    2. Create partitions to be able to read the data:

      ALTER TABLE default.vpc_flow_logs
      location 's3://{your_log_bucket}/AWSLogs/{account_id}/vpcflowlogs/us-east-1/YYYY/MM/DD';
    3. Run the following query in a new query window:

      SELECT day_of_week(from_iso8601_timestamp(dt)) AS
      FROM vpc_flow_logs
      WHERE action = 'REJECT' AND protocol = 6
      order by sourceaddress
      LIMIT 100;

The Cloud Content team comprises subject matter experts hyper focused on services offered by the leading cloud vendors (AWS, GCP, and Azure), as well as cloud-related technologies such as Linux and DevOps. The team is thrilled to share their knowledge to help you build modern tech solutions from the ground up, secure and optimize your environments, and so much more!

What's a lab?

Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.

Provided environment for hands-on practice

We will provide the credentials and environment necessary for you to practice right within your browser.

Guided walkthrough

Follow along with the author’s guided walkthrough and build something new in your provided environment!

Did you know?

On average, you retain 75% more of your learning if you get time for practice.

Start learning by doing today

View Plans