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6 Things To Know About AWS Security Group Limits

6 Things To Know About AWS Security Group Limits

AWS security group limits

If you’re wondering what the security group limits are for your AWS environment, then you have come to the right place.

AWS notates that you have a security group limit of 160 total rules. That includes both inbound and outbound rules, respectively.

Out of the total 120 rules for your particular security group, you can have only 60 inbound and 60 outbound rules.

If you happen to need more than that, feel free to contact your AWS representative and request a quota increase. You can do this by filling out a support ticket.

In terms of the maximum total of security groups for an entire region, you have a default limit of 2,500. This applies to your AWS VPCs per account.

Regarding the security group limit for each network interface attached to a particular EC2 instance, AWS provides each account with a default of about 5.

Users have the ability to adjust this figure and simply request an increase up to about 16 security groups for each network interface.

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As always, it is critically important to leverage AWS’ managed services such as security groups and architect your applications and data in such a way to provide for operational excellence, high availability, and redundancy.

These are just some pillars of the well architected framework, and should always be considered with whatever you happy to be doing in your cloud environments. 

Furthermore, it is also recommended you leverage this tool (security groups) to better protect your environment, which is another very important pillar of the well architected framework. 

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What is the limit on security groups in AWS?

In AWS, the limits for security groups are that you have a limited number of actual security groups per account, per network interface card, and have a limited number of total inbound and outbound rules per security group.

All of these are able to be increased ever so slightly, with the use of a simple support ticket through your AWS console.

How many security groups can be attached to an EC2 instance?

Since an EC2 instance’s primary way of communicating with the rest of your AWS environment and beyond, it is best practice to attach an elastic network interface card.

This is a highly available and redundant offering by AWS, and allows up to 5 security groups per interface. That means, each EC2 instance can have up to 5 or more security groups attached to it at a single time.

If you happen to be needing a service limit quota increase, just fill out a support ticket.

Is an AWS security group free?

You will not be charged for using a security group, or implementing any amount of inbound or outbound rules associated with it.

Despite that, it is important to monitor overall ingress and egress charges that flow in and out of your AWS environment. That is where you will get charged, alongside the actual resources you decide to spin up inside of your VPC.

If you are interested in more specific detail regarding VPC pricing, read more here:

Can an EC2 instance have multiple security groups?

Since each network interface for a particular instance can have up to 5 security groups, then you certainly can have multiple attached simultaneously. 

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It becomes critically important to consider the actual use case and role of your instance.

Understand what that is, and you can begin to associate the right security group for it, that filters and blocks unnecessary traffic from accessing it.

Remember to always be thinking about least privilege, and staying in accordance with the AWS well architected framework!

Final Thoughts

It is very important to begin architecting your applications in a way that takes security into account.

AWS manages and secures the managed services and physical infrastructure, while users’ responsibility is security in the cloud. 

That means that you need to understand general things like security group limits, so you can best plan ahead and truly know what you should be architecting and leveraging as you begin building on AWS.