What do I need to do before migrating my EC2 instance to a sixth generation instance to make sure that I get maximum network performance?

Last updated: 2021-08-25

I want to migrate my Amazon Elastic Compute Cloud (Amazon EC2) instance to a sixth generation instance. What steps should I take before migrating to make sure that I get the optimal networking performance from my new instance?

Short description

The currently available C6gn instance requires an updated driver for Elastic Network Adapter v3 (ENAv3) device generation. Running older ENA drivers with sixth generation instances might lead to suboptimal performance or elastic network interface attachment failure. Before migrating to sixth generation instances, make sure that your AMI includes ENAv3 compatible drivers. Or, if you plan to launch the instance with a new AMI, make sure that you select the correct AMI version with embedded ENAv3 compatible drivers.


To make sure that the appropriate driver is installed before migration, do the following:

1.    If you're using Amazon Linux 2, or if you ever updated the ENA driver for any OS from the Amazon ENA GitHub repository, then verify the ENA driver version by running the following command:

modinfo ena

2.    Use the command results and the following table to verify that your ENA driver is updated. If the results are lower than the value in the Version column of the table, then update the driver.

Environment Version
Linux ENA GitHub ENA driver version v2.2.9
Linux upstream Kernel version 5.9
Amazon Linux 2 Kernel 4.14.186
Red Hat Enterprise Linux (RHEL) RHEL 8.3 kernel 4.18.0-240.1.1.el8_3.ARCH
SUSE Linux Enterprise Server (SLES) SLES 15 SP2 kernel 5.3.18-24.15.1
Linux Ubuntu 20.04 kernel 5.4.0-1025-aws
Windows ENA driver version v2.2.3 and May 2021 Windows AMI or newer
DPDK v20.11
FreeBSD v2.3.1

Note: The following older ENA driver versions result in elastic network interface attachment failure with sixth generation instances.

  • ENA Linux: Less than v1.2.0
  • ENA Windows: Less than v2.0.0
  • ENA DPDK: Less than v1.1.1
  • ENA VMware ESXi: Less than 1.6.0
  • ENA FreeBSD: Less than v2.3.1

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