# Managing functions

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This page was generated from content adapted from the [AWS Developer Guide](https://github.com/awsdocs/aws-lambda-developer-guide.git)
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## Tutorial - Lambda with CLI

* **Note**\
  On Windows, some Bash CLI commands that you commonly use with Lambda (such as `zip`) are not supported by the operating system's built-in terminals. To get a Windows-integrated version of Ubuntu and Bash, [install the Windows Subsystem for Linux](https://docs.microsoft.com/en-us/windows/wsl/install-win10).

## Networking

* **Tip**\
  If your function already includes a VPC configuration from a previous API request, you can send an `UpdateFunctionConfiguration` request without the VPC configuration.
* **Note**\
  Several AWS services offer [VPC endpoints](https://docs.aws.amazon.com/vpc/latest/userguide/vpc-endpoints.html). You can use VPC endpoints to connect to AWS services from within a VPC without internet access.

## Interface VPC endpoints

* **Note**\
  You need to include both the qualified and the unqualified function ARN in the resource.

## File system

* **Note**\
  When you create a file system, you choose a performance mode that can't be changed later. **General purpose** mode has lower latency, and **Max I/O** mode supports a higher maximum throughput and IOPS. For help choosing, see [Amazon EFS performance](https://docs.aws.amazon.com/efs/latest/ug/performance.html) in the *Amazon Elastic File System User Guide*.
* **Note**\
  If your function is not already connected to a VPC, see [Configuring a Lambda function to access resources in a VPC](https://github.com/kevinslin/aws-reference-notes/blob/main/services/aws_lambda/configuration-vpc.md).

## Code signing

* **Note**\
  Functions defined as container images do not support code signing.

## Using layers

* **Note**\
  Make sure that the layers that you add to a function are compatible with the runtime and instruction set architecture of the function.