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Introduction
The Network Access Control List (NACL) and security groups are two essential components of an organization's network security. These security parameters are similar in the way they function as virtual firewalls to secure the network. The most notable similarity is that both NACL and Security Groups use inbound and outbound rules to govern traffic to and from VPC (Virtual Private Cloud) resources.
However, there are some differences between the two technologies. Continue reading to discover more about the subtle distinctions between Security Group and NACL.
What is NACL?
Network Access Control Lists are a network firewall that protects your system and an operational layer of security that secures the VPC (Virtual Private Cloud) for traffic control within the network. NACL adds an extra layer of security to Amazon Web Services. It protects the VPC, which may be viewed as containers for storing subnets. As a result, it helps in the efficient management and control of traffic, as well as the security of data storage.
Advantages of NACL
By implementing network access control, organizations can improve network security, decrease risks, and ensure that only authorized users have access to the network. NACL has the following advantages:
Manages the coordination of user and device network access
Easily detect suspicious network activity
Adds the ability to segment users based on their responsibilities
Allows the user to approve or reject guest networks
Disadvantages of NACL
Some of the disadvantages of NACL over Security Groups are discussed below:
The use of stateless rules in Network Access Control Lists (NACLs) makes rule maintenance challenging, particularly for networks with many nodes
Since NACLs lack application-level filtering, certain forms of attacks can more easily target resources
NACLs only offer a limited view of traffic patterns, which may make it more difficult to spot anomalies or unauthorized access
How Does NACL Work?
Network Access Control List works on the basis of the given rules:
Rule Number: The rule with the lowest number is considered first. If a regulation with a higher number is consistent with the traffic at the time, it will be given a green signal
Type: Within the range, the type of traffic can be provided or customized
Protocol: Any standard number must be used to specify the protocol. You have the option of specifying all or some of the numbers
Port range: The traffic must be contained within the port range selected. For example, port range 80 is used for HTTP transmission
Destination: To reach the destination within the network, the outbound rules must be followed
Allow/refuse: Finally, the network controller decides whether to allow or refuse traffic
What are Security Groups?
Security Groups manage incoming and outgoing traffic to Amazon Web Services, operating as a virtual firewall that helps in traffic flow control. The flow is controlled by different internal and external regulations. Understanding the distinction between NACL and Security Groups begins with the concept of Security Groups. A Security Group is allocated to a certain VPC when it is created. Each group is given a name and a description so that they can be easily found when needed.
Advantages of Security Groups
The role of Security Groups in protecting a network and their various advantages are stated below:
It operates at the instantaneous level without any delay
The response traffic is automatically permitted, and it allows to return traffic regardless of the rules
It supports the cloud environment's security
It controls the traffic that can reach EC2 machines
Disadvantages of Security Groups
The following are some of the drawbacks of Security Groups:
The maximum inbound and outgoing rule for Security Groups is 60
It needs to be specifically assigned to one instance
Since Security Groups do not provide dynamic grouping based on tags or attributes, management in dynamic situations is much more difficult
How do Security Groups Work?
To regulate the traffic permitted to depart from or arrive at the related resources, a Security Group is installed. For instance, when linked to an EC2 machine, it manages all incoming and outgoing traffic. The way NACL and Security Groups operate varies from one another.
Security Groups, however, can only be linked to the specific resources in a VPC for which they were originally built. A Security Group is pre-installed in a VPC by default. After that, specific Security Groups can be made for each VPC.
A VPC's availability zone is configured with a private subnet for database servers and a public subnet for web servers. Separate Security Groups that serve to permit HTTP and HTTPS traffic within the network are included in load balancers.
Security Groups Vs NACL
S. No.
Security Groups
Network Access Control List (NACL)
1
A security group is linked to a service instance. It can be linked to one or more security groups that the user has defined
Multiple subnets can be bound with a single NACL, but only one subnet can be bound at a time
2
The security group functions as a firewall to safeguard EC2 instances
NACL can be viewed as the subnet's firewall or protection
3
When a security group is used, all of the rules are applied to an instance
In the case of NACL, the rules are implemented in the order of their priority, with priority represented by the number allocated to the rule
4
These are stateful, which implies that any modifications made to an incoming rule are automatically applied to an outgoing rule
These are stateless, which means that any change made to an incoming rule does not automatically apply to an outgoing rule
5
They only support rules, and the default behavior is rule denial. Every VPC can be assigned to several security groups
NACL can be used to both support and deny rules. Denial of rules can be specifically specified, such that when the layer sees a specific IP address, it prevents connections from being made to it
6
It is regarded as the first defense layer which helps in the protection of the Amazon Web Services infrastructure
It is regarded as the second line of defense, and it helps in the protection of the AWS stack. It is an optional layer for VPC that gives another layer of security to the Amazon service
7
It cannot block specific IP addresses
NACL supports the blocking of specific IP addresses if found suspicious
Frequently Asked Questions
Does NACL override Security Groups?
Security Groups are applicable at an instance level, whereas Network ACLs are relevant at the subnet level. A subnet's instances will therefore adhere to the NACL guidelines. Security Groups require explicit assignment to an instance. Therefore, any instance in the subnet will be subject to the rule.
Can we block an IP address in NACL?
Malicious assaults are not carried out by hackers using a single IP address. In the process, they switch from one IP address to another. As a result, utilizing Network ACL to prohibit a suspect IP address or range is challenging.
What is the distinction between the default NACL and the default Security Group?
Security Groups are locked down by default, whereas NACL must have a subnet by default. The NACL is configured to allow or deny traffic in and out of the network.
What is EC2?
Amazon Elastic Computation Cloud (Amazon EC2) is a cloud computing online service that provides safe, scalable computation power. It is intended to make web-scale cloud computing more accessible to developers. The easy web service interface of Amazon EC2 allows you to access and configure capacity with minimal effort.
Conclusion
NACL and Security Groups are essential for network protection and management. Companies now hire individuals who have a thorough understanding of NACL and Security Groups, as well as the knowledge required to operate with these technologies. In this blog, we discussed various aspects of Security Groups and NACL and briefly showed Security Groups vs NACL.
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