Use DescribeRouteTables with an Amazon SDK or CLI

To describe your route tables

The following describe-route-tables example retrieves the details about your route tables

aws ec2 describe-route-tables

Output:

{
    "RouteTables": [
        {
            "Associations": [
                {
                    "Main": true,
                    "RouteTableAssociationId": "rtbassoc-0df3f54e06EXAMPLE",
                    "RouteTableId": "rtb-09ba434c1bEXAMPLE"
                }
            ],
            "PropagatingVgws": [],
            "RouteTableId": "rtb-09ba434c1bEXAMPLE",
            "Routes": [
                {
                    "DestinationCidrBlock": "10.0.0.0/16",
                    "GatewayId": "local",
                    "Origin": "CreateRouteTable",
                    "State": "active"
                },
                {
                    "DestinationCidrBlock": "0.0.0.0/0",
                    "NatGatewayId": "nat-06c018cbd8EXAMPLE",
                    "Origin": "CreateRoute",
                    "State": "blackhole"
                }
            ],
            "Tags": [],
            "VpcId": "vpc-0065acced4EXAMPLE",
            "OwnerId": "111122223333"
        },
        {
            "Associations": [
                {
                    "Main": true,
                    "RouteTableAssociationId": "rtbassoc-9EXAMPLE",
                    "RouteTableId": "rtb-a1eec7de"
                }
            ],
            "PropagatingVgws": [],
            "RouteTableId": "rtb-a1eec7de",
            "Routes": [
                {
                    "DestinationCidrBlock": "172.31.0.0/16",
                    "GatewayId": "local",
                    "Origin": "CreateRouteTable",
                    "State": "active"
                },
                {
                    "DestinationCidrBlock": "0.0.0.0/0",
                    "GatewayId": "igw-fEXAMPLE",
                    "Origin": "CreateRoute",
                    "State": "active"
                }
            ],
            "Tags": [],
            "VpcId": "vpc-3EXAMPLE",
            "OwnerId": "111122223333"
        },
        {
            "Associations": [
                {
                    "Main": false,
                    "RouteTableAssociationId": "rtbassoc-0b100c28b2EXAMPLE",
                    "RouteTableId": "rtb-07a98f76e5EXAMPLE",
                    "SubnetId": "subnet-0d3d002af8EXAMPLE"
                }
            ],
            "PropagatingVgws": [],
            "RouteTableId": "rtb-07a98f76e5EXAMPLE",
            "Routes": [
                {
                    "DestinationCidrBlock": "10.0.0.0/16",
                    "GatewayId": "local",
                    "Origin": "CreateRouteTable",
                    "State": "active"
                },
                {
                    "DestinationCidrBlock": "0.0.0.0/0",
                    "GatewayId": "igw-06cf664d80EXAMPLE",
                    "Origin": "CreateRoute",
                    "State": "active"
                }
            ],
            "Tags": [],
            "VpcId": "vpc-0065acced4EXAMPLE",
            "OwnerId": "111122223333"
        }
    ]
}

For more information, see Working with Route Tables in the Amazon VPC User Guide.

    /**
     * @param array $routeTableIds
     * @param array $filters
     * @return array
     */
    public function describeRouteTables(array $routeTableIds = [], array $filters = []): array
    {
        $parameters = [];
        if($routeTableIds){
            $parameters['RouteTableIds'] = $routeTableIds;
        }
        if($filters){
            $parameters['Filters'] = $filters;
        }
        try {
            $paginator = $this->ec2Client->getPaginator("DescribeRouteTables", $parameters);
            $contents = [];
            foreach ($paginator as $result) {
                foreach ($result['RouteTables'] as $object) {
                    $contents[] = $object['RouteTableId'];
                }
            }
        }catch (Ec2Exception $caught){
            echo "There was a problem paginating the results of DescribeRouteTables: {$caught->getAwsErrorMessage()}\n";
            throw $caught;
        }
        return $contents;
    }

Example 1: This example describes all your route tables.

Get-EC2RouteTable

Output:

DestinationCidrBlock    : 10.0.0.0/16
DestinationPrefixListId :
GatewayId               : local
InstanceId              :
InstanceOwnerId         :
NetworkInterfaceId      :
Origin                  : CreateRouteTable
State                   : active
VpcPeeringConnectionId  :

DestinationCidrBlock    : 0.0.0.0/0
DestinationPrefixListId :
GatewayId               : igw-1a2b3c4d
InstanceId              :
InstanceOwnerId         :
NetworkInterfaceId      :
Origin                  : CreateRoute
State                   : active
VpcPeeringConnectionId  :

Example 2: This example returns details for the specified route table.

Get-EC2RouteTable -RouteTableId rtb-1a2b3c4d

Example 3: This example describes the route tables for the specified VPC.

Get-EC2RouteTable -Filter @{ Name="vpc-id"; Values="vpc-1a2b3c4d" }

Output:

Associations    : {rtbassoc-12345678}
PropagatingVgws : {}
Routes          : {, }
RouteTableId    : rtb-1a2b3c4d
Tags            : {}
VpcId           : vpc-1a2b3c4d

class VpcWrapper:
    """Encapsulates Amazon Elastic Compute Cloud (Amazon EC2) Amazon Virtual Private Cloud actions."""

    def __init__(self, ec2_client: boto3.client):
        """
        Initializes the VpcWrapper with an EC2 client.

        :param ec2_client: A Boto3 Amazon EC2 client. This client provides low-level
                           access to AWS EC2 services.
        """
        self.ec2_client = ec2_client

    @classmethod
    def from_client(cls) -> "VpcWrapper":
        """
        Creates a VpcWrapper instance with a default EC2 client.

        :return: An instance of VpcWrapper initialized with the default EC2 client.
        """
        ec2_client = boto3.client("ec2")
        return cls(ec2_client)


    def describe_route_tables(self, vpc_ids: list[str]) -> None:
        """
        Displays information about the route tables in the specified VPC.

        :param vpc_ids: A list of VPC IDs.
        """
        try:
            response = self.ec2_client.describe_route_tables(
                Filters=[{"Name": "vpc-id", "Values": vpc_ids}]
            )
            pp(response["RouteTables"])
        except ClientError as err:
            logger.error(
                "Couldn't describe route tables for VPCs %s. Here's why: %s: %s",
                vpc_ids,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise