This is the new *CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [AWS CloudFormation User Guide](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::EC2::SecurityGroupIngress
<a name="aws-resource-ec2-securitygroupingress"></a>

Adds an inbound (ingress) rule to a security group.

An inbound rule permits instances to receive traffic from the specified IPv4 or IPv6 address range, the IP addresses that are specified by a prefix list, or the instances that are associated with a source security group. For more information, see [Security group rules](https://docs.aws.amazon.com/vpc/latest/userguide/security-group-rules.html).

You must specify exactly one of the following sources: an IPv4 address range, an IPv6 address range, a prefix list, or a security group.

You must specify a protocol for each rule (for example, TCP). If the protocol is TCP or UDP, you must also specify a port or port range. If the protocol is ICMP or ICMPv6, you must also specify the ICMP/ICMPv6 type and code.

Rule changes are propagated to instances associated with the security group as quickly as possible. However, a small delay might occur.

## Syntax
<a name="aws-resource-ec2-securitygroupingress-syntax"></a>

To declare this entity in your CloudFormation template, use the following syntax:

### JSON
<a name="aws-resource-ec2-securitygroupingress-syntax.json"></a>

```
{
  "Type" : "AWS::EC2::SecurityGroupIngress",
  "Properties" : {
      "[CidrIp](#cfn-ec2-securitygroupingress-cidrip)" : String,
      "[CidrIpv6](#cfn-ec2-securitygroupingress-cidripv6)" : String,
      "[Description](#cfn-ec2-securitygroupingress-description)" : String,
      "[FromPort](#cfn-ec2-securitygroupingress-fromport)" : Integer,
      "[GroupId](#cfn-ec2-securitygroupingress-groupid)" : String,
      "[GroupName](#cfn-ec2-securitygroupingress-groupname)" : String,
      "[IpProtocol](#cfn-ec2-securitygroupingress-ipprotocol)" : String,
      "[SourcePrefixListId](#cfn-ec2-securitygroupingress-sourceprefixlistid)" : String,
      "[SourceSecurityGroupId](#cfn-ec2-securitygroupingress-sourcesecuritygroupid)" : String,
      "[SourceSecurityGroupName](#cfn-ec2-securitygroupingress-sourcesecuritygroupname)" : String,
      "[SourceSecurityGroupOwnerId](#cfn-ec2-securitygroupingress-sourcesecuritygroupownerid)" : String,
      "[ToPort](#cfn-ec2-securitygroupingress-toport)" : Integer
    }
}
```

### YAML
<a name="aws-resource-ec2-securitygroupingress-syntax.yaml"></a>

```
Type: AWS::EC2::SecurityGroupIngress
Properties:
  [CidrIp](#cfn-ec2-securitygroupingress-cidrip): String
  [CidrIpv6](#cfn-ec2-securitygroupingress-cidripv6): String
  [Description](#cfn-ec2-securitygroupingress-description): String
  [FromPort](#cfn-ec2-securitygroupingress-fromport): Integer
  [GroupId](#cfn-ec2-securitygroupingress-groupid): String
  [GroupName](#cfn-ec2-securitygroupingress-groupname): String
  [IpProtocol](#cfn-ec2-securitygroupingress-ipprotocol): String
  [SourcePrefixListId](#cfn-ec2-securitygroupingress-sourceprefixlistid): String
  [SourceSecurityGroupId](#cfn-ec2-securitygroupingress-sourcesecuritygroupid): String
  [SourceSecurityGroupName](#cfn-ec2-securitygroupingress-sourcesecuritygroupname): String
  [SourceSecurityGroupOwnerId](#cfn-ec2-securitygroupingress-sourcesecuritygroupownerid): String
  [ToPort](#cfn-ec2-securitygroupingress-toport): Integer
```

## Properties
<a name="aws-resource-ec2-securitygroupingress-properties"></a>

`CidrIp`  <a name="cfn-ec2-securitygroupingress-cidrip"></a>
The IPv4 address range, in CIDR format.  
You must specify exactly one of the following: `CidrIp`, `CidrIpv6`, `SourcePrefixListId`, or `SourceSecurityGroupId`.  
For examples of rules that you can add to security groups for specific access scenarios, see [Security group rules for different use cases](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/security-group-rules-reference.html) in the *Amazon EC2 User Guide*.  
*Required*: No  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`CidrIpv6`  <a name="cfn-ec2-securitygroupingress-cidripv6"></a>
The IPv6 address range, in CIDR format.  
You must specify exactly one of the following: `CidrIp`, `CidrIpv6`, `SourcePrefixListId`, or `SourceSecurityGroupId`.  
For examples of rules that you can add to security groups for specific access scenarios, see [Security group rules for different use cases](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/security-group-rules-reference.html) in the *Amazon EC2 User Guide*.  
*Required*: No  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Description`  <a name="cfn-ec2-securitygroupingress-description"></a>
Updates the description of an ingress (inbound) security group rule. You can replace an existing description, or add a description to a rule that did not have one previously.  
Constraints: Up to 255 characters in length. Allowed characters are a-z, A-Z, 0-9, spaces, and .\$1-:/()\$1,@[]\$1=;\$1\$1\$1\$1\$1  
*Required*: No  
*Type*: String  
*Update requires*: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

`FromPort`  <a name="cfn-ec2-securitygroupingress-fromport"></a>
The start of port range for the TCP and UDP protocols, or an ICMP/ICMPv6 type number. A value of `-1` indicates all ICMP/ICMPv6 types. If you specify all ICMP/ICMPv6 types, you must specify all codes.  
Use this for ICMP and any protocol that uses ports.  
*Required*: No  
*Type*: Integer  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`GroupId`  <a name="cfn-ec2-securitygroupingress-groupid"></a>
The ID of the security group.  
*Required*: No  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`GroupName`  <a name="cfn-ec2-securitygroupingress-groupname"></a>
[Default VPC] The name of the security group. For security groups for a default VPC you can specify either the ID or the name of the security group. For security groups for a nondefault VPC, you must specify the ID of the security group.  
*Required*: No  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`IpProtocol`  <a name="cfn-ec2-securitygroupingress-ipprotocol"></a>
The IP protocol name (`tcp`, `udp`, `icmp`, `icmpv6`) or number (see [Protocol Numbers](http://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml)).  
Use `-1` to specify all protocols. When authorizing security group rules, specifying `-1` or a protocol number other than `tcp`, `udp`, `icmp`, or `icmpv6` allows traffic on all ports, regardless of any port range you specify. For `tcp`, `udp`, and `icmp`, you must specify a port range. For `icmpv6`, the port range is optional; if you omit the port range, traffic for all types and codes is allowed.  
*Required*: Yes  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`SourcePrefixListId`  <a name="cfn-ec2-securitygroupingress-sourceprefixlistid"></a>
The ID of a prefix list.  
*Required*: No  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`SourceSecurityGroupId`  <a name="cfn-ec2-securitygroupingress-sourcesecuritygroupid"></a>
The ID of the security group. You must specify either the security group ID or the security group name. For security groups in a nondefault VPC, you must specify the security group ID.  
*Required*: No  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`SourceSecurityGroupName`  <a name="cfn-ec2-securitygroupingress-sourcesecuritygroupname"></a>
[Default VPC] The name of the source security group. You must specify either the security group ID or the security group name. You can't specify the group name in combination with an IP address range. Creates rules that grant full ICMP, UDP, and TCP access.  
For security groups in a nondefault VPC, you must specify the group ID.  
*Required*: No  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`SourceSecurityGroupOwnerId`  <a name="cfn-ec2-securitygroupingress-sourcesecuritygroupownerid"></a>
[nondefault VPC] The AWS account ID for the source security group, if the source security group is in a different account. You can't specify this property with an IP address range. Creates rules that grant full ICMP, UDP, and TCP access.  
If you specify `SourceSecurityGroupName` or `SourceSecurityGroupId` and that security group is owned by a different account than the account creating the stack, you must specify `SourceSecurityGroupOwnerId`; otherwise, this property is optional.  
*Required*: Conditional  
*Type*: String  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`ToPort`  <a name="cfn-ec2-securitygroupingress-toport"></a>
The end of port range for the TCP and UDP protocols, or an ICMP/ICMPv6 code. A value of `-1` indicates all ICMP/ICMPv6 codes for the specified ICMP type. If you specify all ICMP/ICMPv6 types, you must specify all codes.  
Use this for ICMP and any protocol that uses ports.  
*Required*: No  
*Type*: Integer  
*Update requires*: [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

## Examples
<a name="aws-resource-ec2-securitygroupingress--examples"></a>



**Topics**
+ [VPC security groups with egress and ingress rules](#aws-resource-ec2-securitygroupingress--examples--VPC_security_groups_with_egress_and_ingress_rules)
+ [Allow traffic from a security group in a peered VPC](#aws-resource-ec2-securitygroupingress--examples--Allow_traffic_from_a_security_group_in_a_peered_VPC)

### VPC security groups with egress and ingress rules
<a name="aws-resource-ec2-securitygroupingress--examples--VPC_security_groups_with_egress_and_ingress_rules"></a>

In some cases, you might have an originating (source) security group to which you want to add an outbound rule that allows traffic to a destination (target) security group. The target security group also needs an inbound rule that allows traffic from the source security group. Note that you cannot use the Ref function to specify the outbound and inbound rules for each security group. Doing so creates a circular dependency; you cannot have two resources that depend on each other. Instead, use the egress and ingress resources to declare these outbound and inbound rules, as shown in the following template example. 

#### JSON
<a name="aws-resource-ec2-securitygroupingress--examples--VPC_security_groups_with_egress_and_ingress_rules--json"></a>

```
{
    "Resources": {
        "SourceSG": {
            "Type": "AWS::EC2::SecurityGroup",
            "Properties": {
                "VpcId" : "vpc-1a2b3c4d",
                "GroupDescription": "Sample source security group"
            }
        },
        "TargetSG": {
            "Type": "AWS::EC2::SecurityGroup",
            "Properties": {
                "VpcId" : "vpc-1a2b3c4d",
                "GroupDescription": "Sample target security group"
            }
        },
        "OutboundRule": {
            "Type": "AWS::EC2::SecurityGroupEgress",
            "Properties":{
                "IpProtocol": "tcp",
                "FromPort": 0,
                "ToPort": 65535,
                "DestinationSecurityGroupId": {
                    "Fn::GetAtt": [
                        "TargetSG",
                        "GroupId"
                    ]
                },
                "GroupId": {
                    "Fn::GetAtt": [
                        "SourceSG",
                        "GroupId"
                    ]
                }
            }
        },
        "InboundRule": {
            "Type": "AWS::EC2::SecurityGroupIngress",
            "Properties":{
                "IpProtocol": "tcp",
                "FromPort": 0,
                "ToPort": 65535,
                "SourceSecurityGroupId": {
                    "Fn::GetAtt": [
                        "SourceSG",
                        "GroupId" 
                    ]
                },
                "GroupId": {
                    "Fn::GetAtt": [
                        "TargetSG",
                        "GroupId"
                    ]
                }
            }
        }
    }
}
```

#### YAML
<a name="aws-resource-ec2-securitygroupingress--examples--VPC_security_groups_with_egress_and_ingress_rules--yaml"></a>

```
Resources:
  SourceSG:
    Type: AWS::EC2::SecurityGroup
    Properties:
      VpcId: vpc-1a2b3c4d
      GroupDescription: Sample source security group
  TargetSG:
    Type: AWS::EC2::SecurityGroup
    Properties:
      VpcId: vpc-1a2b3c4d
      GroupDescription: Sample target security group
  OutboundRule:
    Type: AWS::EC2::SecurityGroupEgress
    Properties:
      IpProtocol: tcp
      FromPort: 0
      ToPort: 65535
      DestinationSecurityGroupId:
        Fn::GetAtt:
          - TargetSG
          - GroupId
      GroupId:
        Fn::GetAtt:
          - SourceSG
          - GroupId
  InboundRule:
    Type: AWS::EC2::SecurityGroupIngress
    Properties:
      IpProtocol: tcp
      FromPort: 0
      ToPort: 65535
      SourceSecurityGroupId:
        Fn::GetAtt:
          - SourceSG
          - GroupId
      GroupId:
        Fn::GetAtt:
          - TargetSG
          - GroupId
```

### Allow traffic from a security group in a peered VPC
<a name="aws-resource-ec2-securitygroupingress--examples--Allow_traffic_from_a_security_group_in_a_peered_VPC"></a>

The following example allows one-way traffic from an originating (source) security group to a destination (target) security group. However, in this example the security groups are in peered VPCs across AWS accounts. You might want to allow cross-account traffic if, for example, you create a security scanning resource in one AWS account that you'll use to run diagnostics in another account. This example adds an ingress rule to a target VPC security group that allows incoming traffic from a source security group in a different AWS account. Note that the source security group also needs an egress rule that allows outgoing traffic to the target security group. Because the source security group is in a different account, the following example doesn't use the Ref function to reference the source security group ID but instead directly specifies the security group ID `sg-12345678`. 

#### JSON
<a name="aws-resource-ec2-securitygroupingress--examples--Allow_traffic_from_a_security_group_in_a_peered_VPC--json"></a>

```
{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Resources": {
        "TargetSG": {
            "Type": "AWS::EC2::SecurityGroup",
            "Properties": {
                "VpcId": "vpc-1a2b3c4d",
                "GroupDescription": "Security group allowing ingress for security scanners"
            }
        },
        "InboundRule": {
            "Type": "AWS::EC2::SecurityGroupIngress",
            "Properties": {
                "GroupId": {
                    "Fn::GetAtt": [
                        "TargetSG",
                        "GroupId"
                    ]
                },
                "IpProtocol": "tcp",
                "FromPort": 80,
                "ToPort": 80,
                "SourceSecurityGroupId": "sg-12345678",
                "SourceSecurityGroupOwnerId": "123456789012"
            }
        }
    }
}
```

#### YAML
<a name="aws-resource-ec2-securitygroupingress--examples--Allow_traffic_from_a_security_group_in_a_peered_VPC--yaml"></a>

```
AWSTemplateFormatVersion: 2010-09-09
Resources:
  TargetSG:
    Type: 'AWS::EC2::SecurityGroup'
    Properties:
      VpcId: vpc-1a2b3c4d
      GroupDescription: Security group allowing ingress for security scanners
  InboundRule:
    Type: 'AWS::EC2::SecurityGroupIngress'
    Properties:
      GroupId: !GetAtt TargetSG.GroupId
      IpProtocol: tcp
      FromPort: 80
      ToPort: 80
      SourceSecurityGroupId: sg-12345678
      SourceSecurityGroupOwnerId: '123456789012'
```