Amazon ECS task networking - Amazon Elastic Container Service
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Amazon ECS task networking

Important

If you're using Amazon ECS tasks hosted on Amazon Fargate, see Fargate task networking in the Amazon Elastic Container Service User Guide for Amazon Fargate for networking information that's relevant to your instances.

The networking behavior of Amazon ECS tasks that are hosted on Amazon EC2 instances is dependent on the network mode that's defined in the task definition. We recommend that you use the awsvpc network mode unless you have a specific need to use a different network mode.

The following are the available network modes.

Network mode Linux containers on EC2 Windows containers on EC2 Description

awsvpc

Yes

Yes

The task is allocated its own elastic network interface (ENI) and a primary private IPv4 address. This gives the task the same networking properties as Amazon EC2 instances.

bridge

Yes

No

The task uses Docker's built-in virtual network on Linux, which runs inside each Amazon EC2 instance that hosts the task. The built-in virtual network on Linux uses the bridge Docker network driver. This is the default network mode on Linux if a network mode isn't specified in the task definition.

host

Yes

No

The task uses the host's network which bypasses Docker's built-in virtual network by mapping container ports directly to the ENI of the Amazon EC2 instance that hosts the task. Dynamic port mappings can’t be used in this network mode. A container in a task definition that uses this mode must specify a specific hostPort number. A port number on a host can’t be used by multiple tasks. As a result, you can’t run multiple tasks of the same task definition on a single Amazon EC2 instance.

none

Yes

No

The task has no external network connectivity.

default

No

Yes

The task uses Docker's built-in virtual network on Windows, which runs inside each Amazon EC2 instance that hosts the task. The built-in virtual network on Windows uses the nat Docker network driver. This is the default network mode on Windows if a network mode isn't specified in the task definition.

For more information about Docker networking on Linux, see Networking overview in the Docker Documentation.

For more information about Docker networking on Windows, see Windows container networking in the Microsoft Containers on Windows Documentation.

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