Direct Connect

AWS Direct Connect – DX

Direct Connect Anatomy
~ Last updated on : ~ jayendrapatil ~ 14 Comments

Direct Connect – DX

  • AWS Direct Connect is a network service that provides an alternative to using the Internet to utilize AWS cloud services
  • DX links your internal network to an AWS Direct Connect location over a standard Ethernet fiber-optic cable with one end of the cable connected to your router, the other to an AWS Direct Connect router.
  • Connections can be established with
    • Dedicated connections – 1Gbps, 10Gbps, and 100Gbps capacity.
    • Hosted connection – Speeds of 50, 100, 200, 300, 400, and 500 Mbps can be ordered from any APN partners supporting AWS DX. Also, supports 1, 2, 5 & 10 Gbps with selected partners.
  • Virtual interfaces can be created directly to public AWS services ( e.g. S3) or to VPC, bypassing internet service providers in the network path.
  • DX locations in public Regions or AWS GovCloud (US) can access public services in any other public Region.
  • Each AWS DX location enables connectivity to all AZs within the geographically nearest AWS region.
  • DX supports both the IPv4 and IPv6 communication protocols.

Direct Connect Advantages

  • Reduced Bandwidth Costs
    • All data transferred over the dedicated connection is charged at the reduced data transfer rate rather than Internet data transfer rates.
    • Transferring data to and from AWS directly reduces the bandwidth commitment to the Internet service provider
  • Consistent Network Performance
    • provides a dedicated connection and a more consistent network performance experience than the Internet which can widely vary.
  • AWS Services Compatibility
    • is a network service and works with all of the AWS services like S3, EC2, and VPC
  • Private Connectivity to AWS VPC
    • Using DX Private Virtual Interface a private, dedicated, high bandwidth network connection can be established between the network and VPC
  • Elastic
    • can be easily scaled to meet the needs by either using a higher bandwidth connection or by establishing multiple connections.

Direct Connect Anatomy

Direct Connect Anatomy

  • Amazon maintains AWS Direct Connect PoP across different locations (referred to as Colocation Facilities) which are different from AWS regions.
  • As a consumer, you can either purchase a rack space or use any of the AWS APN Partners which already have the infrastructure within the Colocation Facility and configure a Customer Gateway
  • Connection from the AWS Direct Connect PoP to the AWS regions is maintained by AWS itself.
  • Connection from the Customer Gateway to the Customer Data Center can be established using any Service Provider Network.
  • Connection between the PoP and the Customer gateway within the Colocation Facility is called Cross Connect.
  • Once a DX connection is created with AWS, an LOA-CFA (Letter Of Authority – Connecting Facility Assignment) would be received.
  • LOA-CFA can be handover to the Colocation Facility or the APN Partner to establish the Cross Connect
  • Once the Cross Connect and the connectivity between the CGW and Customer DataCenter are established, Virtual Interfaces can be created
  • AWS Direct Connect requires a VGW to access the AWS VPC.
  • Virtual Interfaces – VIF

    • Each connection requires a Virtual Interface
    • Each connection can be configured with one or more virtual interfaces.
    • Supports, Public, Private, and Transit Virtual Interface
    • Each VIF needs a VLAN ID, interface IP address, ASN, and BGP key.
  • To use the connection with another AWS account, a hosted virtual interface (Hosted VIF) can be created for that account. These hosted virtual interfaces work the same as standard virtual interfaces and can connect to public resources or a VPC.

Direct Connect Network Requirements

  • Single-mode fiber with
    • a 1000BASE-LX (1310 nm) transceiver for 1 gigabit Ethernet,
    • a 10GBASE-LR (1310 nm) transceiver for 10 gigabits, or
    • a 100GBASE-LR4 for 100 gigabit Ethernet.
  • 802.1Q VLAN encapsulation must be supported
  • Auto-negotiation for a port must be disabled so that the speed and mode (half or full duplex) cannot be modified and should be manually configured
  • Border Gateway Protocol (BGP) and BGP MD5 authentication must be supported
  • Bidirectional Forwarding Detection (BFD) is optional and helps in quick failure detection.

Direct Connect Connections

  • Dedicated Connection
    • provides a physical Ethernet connection associated with a single customer
    • Customers can request a dedicated connection through the AWS Direct Connect console, the CLI, or the API.
    • support port speeds of 1 Gbps, 10 Gbps, and 100 Gbps.
    • supports multiple virtual interfaces (current limit of 50)
  • Hosted Connection
    • A physical Ethernet connection that an AWS Direct Connect Partner provisions on behalf of a customer.
    • Customers request a hosted connection by contacting a partner in the AWS Direct Connect Partner Program, which provisions the connection
    • Support port speeds of 50 Mbps, 100 Mbps, 200 Mbps, 300 Mbps, 400 Mbps, 500 Mbps, 1 Gbps, 2 Gbps, 5 Gbps, and 10 Gbps
    • 1 Gbps, 2 Gbps, 5 Gbps or 10 Gbps hosted connections are supported by limited partners.
    • supports a single virtual interface
    • AWS uses traffic policing on hosted connections and excess traffic is dropped.

Direct Connect Virtual Interfaces – VIF

  • Public Virtual Interface
    • enables connectivity to all the AWS Public IP addresses
    • helps connect to public resources e.g. SQS, S3, EC2, Glacier, etc which are reachable publicly only.
    • can be used to access all public resources across regions
    • allows a maximum of 1000 prefixes. You can summarize the prefixes into a larger range to reduce the number of prefixes.
    • does not support Jumbo frames.
  • Private Virtual Interface
    • helps connect to the VPC for e.g. instances with a private IP address
    • supports
      • Virtual Private Gateway
        • Allows connections only to a single specific VPC with the attached VGW in the same region
        • Private VIF and Virtual Private Gateway – VGW should be in the same region
      • Direct Connect Gateway
        • Allows connections to multiple VPCs in multiple regions.
    • allows a maximum of 100 prefixes. You can summarize the prefixes into a larger range to reduce the number of prefixes.
    • supports Jumbo frames with 9001 MTU
    • provides access to EC2 instances, Private IPs, and VPC Interface Endpoints.
    • does not provide access to VPC DNS resolver and VPC Gateway Endpoints
  • Transit Virtual Interface
    • helps access one or more VPC Transit Gateways associated with Direct Connect Gateways.
    • supports Jumbo frames with 8500 MTU

Direct Connect Redundancy

Redunant Direct Connect Architecture

  • Direct Connect connections do not provide redundancy and have multiple single points of failures w.r.t to the hardware devices as each connection consists of a single dedicated connection between ports on your router and an Amazon router.
  • Redundancy can be provided by
    • Establishing a second DX connection, preferably in a different Colocation Facility using a different router and AWS DX PoP.
    • IPsec VPN connection between the Customer DC to the VGW.
  • For Multiple ports requested in the same AWS Direct Connect location, Amazon itself makes sure they are provisioned on redundant Amazon routers to prevent impact from a hardware failure

High Resiliency – 99.9%

Direct Connect High Resiliency

  • High resiliency for critical workloads can be achieved by using two single connections to multiple locations.
  • It provides resiliency against connectivity failures caused by a fiber cut or a device failure. It also helps prevent a complete location failure.

Maximum Resiliency – 99.99%

Direct Connect Max Resiliency

  • Maximum resiliency for critical workloads can be achieved using separate connections that terminate on separate devices in more than one location.
  • It provides resiliency against device, connectivity, and complete location failures.

Direct Connect LAG – Link Aggregation Group

Direct Connect LAG

  • A LAG is a logical interface that uses the Link Aggregation Control Protocol (LACP) to aggregate multiple connections at a single AWS Direct Connect endpoint, treating them as a single, managed connection.
  • LAG can combine multiple connections to increase available bandwidth.
  • LAG can be created from existing or new connections.
  • Existing connections (whether standalone or part of another LAG) with the LAG can be associated after LAG creation.
  • LAG needs following rules
    • All connections must use the same bandwidth and port speed of 1, 10, 100 Gbps.
    • All connections must be dedicated connections.
    • Maximum of four connections in a LAG. Each connection in the LAG counts toward the overall connection limit for the Region.
    • All connections in the LAG must terminate at the same AWS Direct Connect endpoint.
  • Multi-chassis LAG (MLAG) is not supported by AWS.
  • LAG doesn’t make the connectivity to AWS more resilient.
  • LAG connections operate in Active/Active mode.
  • LAG supports attributes to define a minimum number of operational connections for the LAG function, with a default value of 0.

Direct Connect Failover

  • Bidirectional Forwarding Detection – BFD is a detection protocol that provides fast forwarding path failure detection times. These fast failure detection times facilitate faster routing reconvergence times.
  • When connecting to AWS services over DX connections it is recommended to enable BFD for fast failure detection and failover.
  • By default, BGP waits for three keep-alives to fail at a hold-down time of 90 seconds. Enabling BFD for the DX connection allows the BGP neighbor relationship to be quickly torn down.
  • Asynchronous BFD is automatically enabled for each DX virtual interface, but will not take effect until it’s configured on your router.
  • AWS has set the BFD liveness detection minimum interval to 300, and the BFD liveness detection multiplier to 3
  • It’s a best practice not to configure graceful restart and BFD at the same time to avoid failover or connection issues. For fast failover, configure BFD without graceful restart enabled.
  • BFD is supported for LAGs.

Direct Connect Security

  • Direct Connect does not encrypt the traffic that is in transit by default. To encrypt the data in transit that traverses DX, you must use the transit encryption options for that service.
  • DX connections can be secured
    • with IPSec VPN to provide secure, reliable connectivity.
    • with MACsec to encrypt the data from the corporate data center to the DX location.
  • MAC Security (MACsec)
    • is an IEEE standard that provides data confidentiality, data integrity, and data origin authenticity.
    • provides Layer2 security for 10Gbps and 100Gbps Dedicated Connections only.
    • delivers native, near line-rate, point-to-point encryption ensuring that data communications between AWS and the data center, office, or colocation facility remain protected.
    • removes VPN limitation that required the aggregation of multiple IPsec VPN tunnels to work around the throughput limits of using a single VPN connection.

Direct Connect Gateway

Refer blog post @ Direct Connect Gateway

Direct Connect vs IPSec VPN Connections

AWS Direct Connect vs VPN

Refer blog post @ Direct Connect vs VPN

AWS Certification Exam Practice Questions

  • Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
  • AWS services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
  • AWS exam questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated
  • Open to further feedback, discussion and correction.
  1. You are building a solution for a customer to extend their on-premises data center to AWS. The customer requires a 50-Mbps dedicated and private connection to their VPC. Which AWS product or feature satisfies this requirement?
    1. Amazon VPC peering
    2. Elastic IP Addresses
    3. AWS Direct Connect
    4. Amazon VPC virtual private gateway
  2. Is there any way to own a direct connection to Amazon Web Services?
    1. You can create an encrypted tunnel to VPC, but you don’t own the connection.
    2. Yes, it’s called Amazon Dedicated Connection.
    3. No, AWS only allows access from the public Internet.
    4. Yes, it’s called Direct Connect
  3. An organization has established an Internet-based VPN connection between their on-premises data center and AWS. They are considering migrating from VPN to AWS Direct Connect. Which operational concern should drive an organization to consider switching from an Internet-based VPN connection to AWS Direct Connect?
    1. AWS Direct Connect provides greater redundancy than an Internet-based VPN connection.
    2. AWS Direct Connect provides greater resiliency than an Internet-based VPN connection.
    3. AWS Direct Connect provides greater bandwidth than an Internet-based VPN connection.
    4. AWS Direct Connect provides greater control of network provider selection than an Internet-based VPN connection.
  4. Does AWS Direct Connect allow you access to all Availabilities Zones within a Region?
    1. Depends on the type of connection
    2. No
    3. Yes
    4. Only when there’s just one availability zone in a region. If there are more than one, only one availability zone can be accessed directly.
  5. A customer has established an AWS Direct Connect connection to AWS. The link is up and routes are being advertised from the customer’s end, however, the customer is unable to connect from EC2 instances inside its VPC to servers residing in its datacenter. Which of the following options provide a viable solution to remedy this situation? (Choose 2 answers)
    1. Add a route to the route table with an IPSec VPN connection as the target (deals with VPN)
    2. Enable route propagation to the Virtual Private Gateway (VGW)
    3. Enable route propagation to the customer gateway (CGW) (route propagation is enabled on VGW)
    4. Modify the route table of all Instances using the ‘route’ command. (no route command available)
    5. Modify the Instances VPC subnet route table by adding a route back to the customer’s on-premises environment.
  6. A company has configured and peered two VPCs: VPC-1 and VPC-2. VPC-1 contains only private subnets, and VPC-2 contains only public subnets. The company uses a single AWS Direct Connect connection and private virtual interface to connect their on-premises network with VPC-1. Which two methods increase the fault tolerance of the connection to VPC-1? Choose 2 answers
    1. Establish a hardware VPN over the internet between VPC-2 and the on-premises network. (Peered VPC does not support Edge to Edge Routing)
    2. Establish a hardware VPN over the internet between VPC-1 and the on-premises network
    3. Establish a new AWS Direct Connect connection and private virtual interface in the same region as VPC-2 (Peered VPC does not support Edge to Edge Routing)
    4. Establish a new AWS Direct Connect connection and private virtual interface in a different AWS region than VPC-1 (need to be in the same region as VPC-1)
    5. Establish a new AWS Direct Connect connection and private virtual interface in the same AWS region as VPC-1
  7. Your company previously configured a heavily used, dynamically routed VPN connection between your on-premises data center and AWS. You recently provisioned a Direct Connect connection and would like to start using the new connection. After configuring Direct Connect settings in the AWS Console, which of the following options will provide the most seamless transition for your users?
    1. Delete your existing VPN connection to avoid routing loops configure your Direct Connect router with the appropriate settings and verify network traffic is leveraging Direct Connect.
    2. Configure your Direct Connect router with a higher BGP priority than your VPN router, verify network traffic is leveraging Direct Connect, and then delete your existing VPN connection.
    3. Update your VPC route tables to point to the Direct Connect connection configure your Direct Connect router with the appropriate settings verify network traffic is leveraging Direct Connect and then delete the VPN connection.
    4. Configure your Direct Connect router, update your VPC route tables to point to the Direct Connect connection, configure your VPN connection with a higher BGP priority. And verify network traffic is leveraging the Direct Connect connection
  8. You are designing the network infrastructure for an application server in Amazon VPC. Users will access all the application instances from the Internet as well as from an on-premises network The on-premises network is connected to your VPC over an AWS Direct Connect link. How would you design routing to meet the above requirements?
    1. Configure a single routing table with a default route via the Internet gateway. Propagate a default route via BGP on the AWS Direct Connect customer router. Associate the routing table with all VPC subnets (propagating the default route would cause conflict)
    2. Configure a single routing table with a default route via the internet gateway. Propagate specific routes for the on-premises networks via BGP on the AWS Direct Connect customer router. Associate the routing table with all VPC subnets.
    3. Configure a single routing table with two default routes: one to the internet via an Internet gateway the other to the on-premises network via the VPN gateway use this routing table across all subnets in your VPC. (there cannot be 2 default routes)
    4. Configure two routing tables one that has a default route via the Internet gateway and another that has a default route via the VPN gateway Associate both routing tables with each VPC subnet. (as the instances have to be in the public subnet and should have a single routing table associated with them)
  9. You are implementing AWS Direct Connect. You intend to use AWS public service endpoints such as Amazon S3, across the AWS Direct Connect link. You want other Internet traffic to use your existing link to an Internet Service Provider. What is the correct way to configure AWS Direct Connect for access to services such as Amazon S3?
    1. Configure a public Interface on your AWS Direct Connect link. Configure a static route via your AWS Direct Connect link that points to Amazon S3. Advertise a default route to AWS using BGP.
    2. Create a private interface on your AWS Direct Connect link. Configure a static route via your AWS Direct Connect link that points to Amazon S3 Configure specific routes to your network in your VPC.
    3. Create a public interface on your AWS Direct Connect link. Redistribute BGP routes into your existing routing infrastructure advertise specific routes for your network to AWS
    4. Create a private interface on your AWS Direct connect link. Redistribute BGP routes into your existing routing infrastructure and advertise a default route to AWS.
  10. You have been asked to design network connectivity between your existing data centers and AWS. Your application’s EC2 instances must be able to connect to existing backend resources located in your data center. Network traffic between AWS and your data centers will start small, but ramp up to 10s of GB per second over the course of several months. The success of your application is dependent upon getting to market quickly. Which of the following design options will allow you to meet your objectives?
    1. Quickly create an internal ELB for your backend applications, submit a DirectConnect request to provision a 1 Gbps cross-connect between your data center and VPC, then increase the number or size of your DirectConnect connections as needed.
    2. Allocate EIPs and an Internet Gateway for your VPC instances to use for quick, temporary access to your backend applications, then provision a VPN connection between a VPC and existing on-premises equipment.
    3. Provision a VPN connection between a VPC and existing on-premises equipment, submit a DirectConnect partner request to provision cross connects between your data center and the DirectConnect location, then cut over from the VPN connection to one or more DirectConnect connections as needed.
    4. Quickly submit a DirectConnect request to provision a 1 Gbps cross connect between your data center and VPC, then increase the number or size of your DirectConnect connections as needed.
  11. You are tasked with moving a legacy application from a virtual machine running inside your datacenter to an Amazon VPC. Unfortunately, this app requires access to a number of on-premises services and no one who configured the app still works for your company. Even worse there’s no documentation for it. What will allow the application running inside the VPC to reach back and access its internal dependencies without being reconfigured? (Choose 3 answers)
    1. An AWS Direct Connect link between the VPC and the network housing the internal services (VPN or a DX for communication)
    2. An Internet Gateway to allow a VPN connection. (Virtual and Customer gateway is needed)
    3. An Elastic IP address on the VPC instance (Don’t need a EIP as private subnets can also interact with on-premises network)
    4. An IP address space that does not conflict with the one on-premises (IP address cannot conflict)
    5. Entries in Amazon Route 53 that allow the Instance to resolve its dependencies’ IP addresses (Route 53 is not required)
    6. A VM Import of the current virtual machine (VM Import to copy the VM to AWS as there is no documentation it can’t be configured from scratch)

References

AWS Cloud Migration Services

~ Last updated on : ~ jayendrapatil ~ 6 Comments

AWS Cloud Migration Services

  • AWS Cloud Migration services help to address a lot of common use cases such as
    • cloud migration,
    • disaster recovery,
    • data center decommission, and
    • content distribution.
  • For migrating data from on-premises to AWS, the major aspect for consideration are
    • amount of data and network speed
    • data security in transit
    • existing application knowledge for recreation

Application & Database Cloud Migration Services

AWS Migration Hub

  • provides a centralized, single place to discover the existing servers, plan migrations, and track the status of each application migration.
  • provides visibility into the application portfolio and streamlines planning and tracking.
  • helps visualize the connections and the status of the migrating servers and databases, regardless of which migration tool is used.
  • stores all the data in the selected Home Region and provides a single repository of discovery and migration planning information for the entire portfolio and a single view of migrations into multiple AWS Regions.
  • helps track the status of the migrations in all AWS Regions, provided the migration tools are available in that Region.
  • helps understand the environment by letting you explore information collected by AWS discovery tools and stored in the AWS Application Discovery Service’s repository.
  • supports migration status updates from the following tools:
  • migration tools send migration status to the selected Home Region
  • supports EC2 instance recommendations, that provide you with the ability to estimate the cost of running the existing servers in AWS.
  • supports Strategy Recommendations, that help easily build a migration and modernization strategy for the applications running on-premises or in AWS.

AWS Application Discovery Service

  • AWS Application Discovery Service helps plan migration to the AWS cloud by collecting usage and configuration data about the on-premises servers.
  • helps enterprises obtain a snapshot of the current state of their data center servers by collecting server specification information, hardware configuration, performance data, details of running processes, and network connections
  • is integrated with AWS Migration Hub,
    • which simplifies migration tracking as it aggregates migration status information into a single console.
    • can help view the discovered servers, group them into applications, and then track the migration status of each application.
  • discovered data for all the regions is stored in the AWS Migration Hub home Region.
  • The data can be exported for analysis in Microsoft Excel or AWS analysis tools such as Amazon Athena and Amazon QuickSight.
  • supports both agent and agentless-based on-premises tooling, in addition to file-based import for performing discovery and collecting data about the on-premises servers.

AWS Server Migration Service (SMS)

  • is an agentless service that makes it easier and faster to migrate thousands of on-premises workloads to AWS.
  • helps automate, schedule, and track incremental replications of live server volumes, making it easier to coordinate large-scale server migrations.
  • currently supports migration of virtual machines from VMware vSphere,  Windows Hyper-V and Azure VM to AWS
  • supports migrating Windows Server 2003, 2008, 2012, and 2016, and Windows 7, 8, and 10; Red Hat Enterprise Linux (RHEL), SUSE/SLES, CentOS, Ubuntu, Oracle Linux, Fedora, and Debian Linux OS
  • replicates each server volume, which is saved as a new AMI, which can be launched as an EC2 instance
  • is a significant enhancement of EC2 VM Import/Export service
  • is used to Re-host

AWS Database Migration Service (DMS)

  • helps migrate databases to AWS quickly and securely.
  • source database remains fully operational during the migration, minimizing downtime to applications that rely on the database.
  • supports homogeneous migrations such as Oracle to Oracle, as well as heterogeneous migrations between different database platforms, such as Oracle or Microsoft SQL Server to Amazon Aurora.
  • monitors for replication tasks, network or host failures, and automatically provisions a host replacement in case of failures that can’t be repaired
  • supports both one-time data migration into RDS and EC2-based databases as well as for continuous data replication
  • supports continuous replication of the data with high availability and consolidate databases into a petabyte-scale data warehouse by streaming data to Amazon Redshift and Amazon S3
  • provides free AWS Schema Conversion Tool (SCT) that automates the conversion of Oracle PL/SQL and SQL Server T-SQL code to equivalent code in the Amazon Aurora / MySQL dialect of SQL or the equivalent PL/pgSQL code in PostgreSQL

AWS EC2 VM Import/Export

  • allows easy import of virtual machine images from existing environment to EC2 instances and export them back to on-premises environment
  • allows leveraging of existing investments in the virtual machines, built to meet compliance requirements, configuration management and IT security by bringing those virtual machines into EC2 as ready-to-use instances
  • Common usages include
    • Migrate Existing Applications and Workloads to EC2, allowing preserving of the software and settings configured in the existing VMs.
    • Copy Your VM Image Catalog to EC2
    • Create a Disaster Recovery Repository for your VM images

Data Transfer Services

VPN

  • connection utilizes IPSec to establish encrypted network connectivity between on-premises network and VPC over the Internet.
  • connections can be configured in minutes and a good solution for an immediate need, have low to modest bandwidth requirements, and can tolerate the inherent variability in Internet-based connectivity.
  • still requires internet and be configured using VGW and CGW

AWS Direct Connect

  • provides a dedicated physical connection between the corporate network and AWS Direct Connect location with no data transfer over the Internet.
  • helps bypass Internet service providers (ISPs) in the network path
  • helps reduce network costs, increase bandwidth throughput, and provide a more consistent network experience than with Internet-based connection
  • takes time to setup and involves third parties
  • are not redundant and would need another direct connect connection or a VPN connection
  •  Security
    • provides a dedicated physical connection without internet
    • For additional security can be used with VPN

AWS Import/Export (upgraded to Snowball)

  • accelerates moving large amounts of data into and out of AWS using secure Snowball appliances
  • AWS transfers the data directly onto and off of the storage devices using Amazon’s high-speed internal network, bypassing the Internet
  • Data Migration
    • for significant data size, AWS Import/Export is faster than Internet transfer is and more cost-effective than upgrading the connectivity
    • if loading the data over the Internet would take a week or more, AWS Import/Export should be considered
    • data from appliances can be imported to S3, Glacier and EBS volumes and exported from S3
    • not suitable for applications that cannot tolerate offline transfer time
  •  Security
    • Snowball uses an industry-standard Trusted Platform Module (TPM) that has a dedicated processor designed to detect any unauthorized modifications to the hardware, firmware, or software to physically secure the AWS Snowball device.

Snow Family

  • AWS Snowball
    • is a petabyte-scale data transfer service built around a secure suitcase-sized device that moves data into and out of the AWS Cloud quickly and efficiently.
    • transfers the data to S3 bucket
    • transfer times are about a week from start to finish.
    • are commonly used to ship terabytes or petabytes of analytics data, healthcare and life sciences data, video libraries, image repositories, backups, and archives as part of data center shutdown, tape replacement, or application migration projects.
  • AWS Snowball Edge devices
    • contain slightly larger capacity and an embedded computing platform that helps perform simple processing tasks.
    • can be rack shelved and may also be clustered together, making it simpler to collect and store data in extremely remote locations.
    • commonly used in environments with intermittent connectivity (such as manufacturing, industrial, and transportation); or in extremely remote locations (such as military or maritime operations) before shipping them back to AWS data centers.
    • delivers serverless computing applications at the network edge using AWS Greengrass and Lambda functions.
    • common use cases include capturing IoT sensor streams, on-the-fly media transcoding, image compression, metrics aggregation and industrial control signaling and alarming.
  • AWS Snowmobile
    • moves up to 100PB of data (equivalent to 1,250 AWS Snowball devices) in a 45-foot long ruggedized shipping container and is ideal for multi-petabyte or Exabyte-scale digital media migrations and datacenter shutdowns.
    • arrives at the customer site and appears as a network-attached data store for more secure, high-speed data transfer. After data is transferred to Snowmobile, it is driven back to an AWS Region where the data is loaded into S3.
    • is tamper-resistant, waterproof, and temperature controlled with multiple layers of logical and physical security — including encryption, fire suppression, dedicated security personnel, GPS tracking, alarm monitoring, 24/7 video surveillance, and an escort security vehicle during transit.

AWS Storage Gateway

  • connects an on-premises software appliance with cloud-based storage to provide seamless and secure integration between an organization’s on-premises IT environment and the AWS storage infrastructure
  • provides low-latency performance by maintaining frequently accessed data on-premises while securely storing all of the data encrypted in S3 or Glacier.
  • for disaster recovery scenarios, Storage Gateway, together with EC2, can serve as a cloud-hosted solution that mirrors the entire production environment
  • Data Migration
    • with gateway-cached volumes, S3 can be used to hold primary data while frequently accessed data is cached locally for faster access reducing the need to scale on premises storage infrastructure
    • with gateway-stored volumes, entire data is stored locally while asynchronously backing up data to S3
    • with gateway-VTL, offline data archiving can be performed by presenting existing backup application with an iSCSI-based VTL consisting of a virtual media changer and virtual tape drives
  •  Security
    • Encrypts all data in transit to and from AWS by using SSL/TLS.
    • All data in AWS Storage Gateway is encrypted at rest using AES-256.
    • Authentication between the gateway and iSCSI initiators can be secured by using Challenge-Handshake Authentication Protocol (CHAP).

Simple Storage Service – S3

  • Data Transfer
    • Files up to 5GB can be transferred using single operation
    • Multipart uploads can be used to upload files up to 5 TB and speed up data uploads by dividing the file into multiple parts
    • transfer rate still limited by the network speed
  •  Security
    • Data in transit can be secured by using SSL/TLS or client-side encryption.
    • Encrypt data at-rest by performing server-side encryption using Amazon S3-Managed Keys (SSE-S3), AWS Key Management Service (KMS)-Managed Keys (SSE-KMS), or Customer Provided Keys (SSE-C). Or by performing client-side encryption using AWS KMS–Managed Customer Master Key (CMK) or Client-Side Master Key.

AWS Certification Exam Practice Questions

  • Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
  • AWS services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
  • AWS exam questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated
  • Open to further feedback, discussion and correction.
  • Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
  • AWS services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
  • AWS exam questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated
  • Open to further feedback, discussion and correction.
  1. Your must architect the migration of a web application to AWS. The application consists of Linux web servers running a custom web server. You are required to save the logs generated from the application to a durable location. What options could you select to migrate the application to AWS? (Choose 2)
    1. Create an AWS Elastic Beanstalk application using the custom web server platform. Specify the web server executable and the application project and source files. Enable log file rotation to Amazon Simple Storage Service (S3). (EB does not work with Custom server executable)
    2. Create Dockerfile for the application. Create an AWS OpsWorks stack consisting of a custom layer. Create custom recipes to install Docker and to deploy your Docker container using the Dockerfile. Create custom recipes to install and configure the application to publish the logs to Amazon CloudWatch Logs (although this is one of the option, the last sentence mentions configure the application to push the logs to S3, which would need changes to application as it needs to use SDK or CLI)
    3. Create Dockerfile for the application. Create an AWS OpsWorks stack consisting of a Docker layer that uses the Dockerfile. Create custom recipes to install and configure Amazon Kinesis to publish the logs into Amazon CloudWatch. (Kinesis not needed)
    4. Create a Dockerfile for the application. Create an AWS Elastic Beanstalk application using the Docker platform and the Dockerfile. Enable logging the Docker configuration to automatically publish the application logs. Enable log file rotation to Amazon S3. (Use Docker configuration with awslogs and EB with Docker)
    5. Use VM import/Export to import a virtual machine image of the server into AWS as an AMI. Create an Amazon Elastic Compute Cloud (EC2) instance from AMI, and install and configure the Amazon CloudWatch Logs agent. Create a new AMI from the instance. Create an AWS Elastic Beanstalk application using the AMI platform and the new AMI. (Use VM Import/Export to create AMI and CloudWatch logs agent to log)
  2. Your company hosts an on-premises legacy engineering application with 900GB of data shared via a central file server. The engineering data consists of thousands of individual files ranging in size from megabytes to multiple gigabytes. Engineers typically modify 5-10 percent of the files a day. Your CTO would like to migrate this application to AWS, but only if the application can be migrated over the weekend to minimize user downtime. You calculate that it will take a minimum of 48 hours to transfer 900GB of data using your company’s existing 45-Mbps Internet connection. After replicating the application’s environment in AWS, which option will allow you to move the application’s data to AWS without losing any data and within the given timeframe?
    1. Copy the data to Amazon S3 using multiple threads and multi-part upload for large files over the weekend, and work in parallel with your developers to reconfigure the replicated application environment to leverage Amazon S3 to serve the engineering files. (Still limited by 45 Mbps speed with minimum 48 hours when utilized to max)
    2. Sync the application data to Amazon S3 starting a week before the migration, on Friday morning perform a final sync, and copy the entire data set to your AWS file server after the sync completes. (Works best as the data changes can be propagated over the week and are fractional and downtime would be know)
    3. Copy the application data to a 1-TB USB drive on Friday and immediately send overnight, with Saturday delivery, the USB drive to AWS Import/Export to be imported as an EBS volume, mount the resulting EBS volume to your AWS file server on Sunday. (Downtime is not known when the data upload would be done, although Amazon says the same day the package is received)
    4. Leverage the AWS Storage Gateway to create a Gateway-Stored volume. On Friday copy the application data to the Storage Gateway volume. After the data has been copied, perform a snapshot of the volume and restore the volume as an EBS volume to be attached to your AWS file server on Sunday. (Still uses the internet)
  3. You are tasked with moving a legacy application from a virtual machine running inside your datacenter to an Amazon VPC. Unfortunately this app requires access to a number of on-premises services and no one who configured the app still works for your company. Even worse there’s no documentation for it. What will allow the application running inside the VPC to reach back and access its internal dependencies without being reconfigured? (Choose 3 answers)
    1. An AWS Direct Connect link between the VPC and the network housing the internal services
    2. An Internet Gateway to allow a VPN connection. (Virtual and Customer gateway is needed)
    3. An Elastic IP address on the VPC instance
    4. An IP address space that does not conflict with the one on-premises
    5. Entries in Amazon Route 53 that allow the Instance to resolve its dependencies’ IP addresses
    6. A VM Import of the current virtual machine
  4. An enterprise runs 103 line-of-business applications on virtual machines in an on-premises data center. Many of the applications are simple PHP, Java, or Ruby web applications, are no longer actively developed, and serve little traffic. Which approach should be used to migrate these applications to AWS with the LOWEST infrastructure costs?
    1. Deploy the applications to single-instance AWS Elastic Beanstalk environments without a load balancer.
    2. Use AWS SMS to create AMIs for each virtual machine and run them in Amazon EC2.
    3. Convert each application to a Docker image and deploy to a small Amazon ECS cluster behind an Application Load Balancer.
    4. Use VM Import/Export to create AMIs for each virtual machine and run them in single-instance AWS Elastic Beanstalk environments by configuring a custom image.

References

AWS Network Connectivity Options

~ Last updated on : ~ jayendrapatil ~ 3 Comments

AWS Network Connectivity Options

Internet Gateway

  • provides Internet connectivity to VPC
  • is a horizontally scaled, redundant, and highly available component that allows communication between instances in your VPC and the internet.
  • imposes no availability risks or bandwidth constraints on your network traffic.
  • serves two purposes: to provide a target in the VPC route tables for internet-routable traffic and to perform NAT for instances that have not been assigned public IPv4 addresses.
  • supports IPv4 and IPv6 traffic.

NAT Gateway

  • enables instances in a private subnet to connect to the internet or other AWS services, but prevents the Internet from initiating connections with the instances.
  • Private NAT gateway allows instances in private subnets to connect to other VPCs or the on-premises network.

Egress Only Internet Gateway

  • NAT devices are not supported for IPv6 traffic, use an Egress-only Internet gateway instead
  • Egress-only Internet gateway is a horizontally scaled, redundant, and highly available VPC component that
  • Egress-only Internet gateway allows outbound communication over IPv6 from instances in the VPC to the Internet and prevents the Internet from initiating an IPv6 connection with your instances.

VPC Endpoints

  • VPC endpoint provides a private connection from VPC to supported AWS services and VPC endpoint services powered by PrivateLink without requiring an internet gateway, NAT device, VPN connection, or AWS Direct Connect connection.
  • Instances in the VPC do not require public IP addresses to communicate with resources in the service. Traffic between the VPC and the other service does not leave the Amazon network.
  • VPC Endpoints are virtual devices and are horizontally scaled, redundant, and highly available VPC components that allow communication between instances in the VPC and services without imposing availability risks or bandwidth constraints on the network traffic.
  • VPC Endpoints are of two types
    • Interface Endpoints – is an elastic network interface with a private IP address that serves as an entry point for traffic destined to supported services.
    • Gateway Endpoints – is a gateway that is a target for a specified route in your route table, used for traffic destined to a supported AWS service. Currently only Amazon S3 and DynamoDB.

VPC Private LinksAWS Private Links

  • provides private connectivity between VPCs, AWS services, and your on-premises networks without exposing your traffic to the public internet.
  • helps privately expose a service/application residing in one VPC (service provider) to other VPCs (consumer) within an AWS Region in a way that only consumer VPCs initiate connections to the service provider VPC.
  • With ALB as a target of NLB, ALB’s advanced routing capabilities can be combined with AWS PrivateLink.

VPC Peering

  • enables networking connection between two VPCs to route traffic between them using private IPv4 addresses or IPv6 addresses
  • connections can be created between your own VPCs, or with a VPC in another AWS account.
  • enables full bidirectional connectivity between the VPCs
  • supports inter-region VPC peering connection
  • uses existing underlying AWS infrastructure
  • does not have a single point of failure for communication or a bandwidth bottleneck.
  • VPC Peering connections have limitations
    • cannot be used with Overlapping CIDR blocks
    • does not provide Transitive peering
    • does not support Edge to Edge routing through Gateway or private connection
  • is best used when resources in one VPC must communicate with resources in another VPC, the environment of both VPCs is controlled and secured, and the number of VPCs to be connected is less than 10

VPN CloudHub

  • AWS VPN CloudHub allows you to securely communicate from one site to another using AWS Managed VPN or Direct Connect
  • AWS VPN CloudHub operates on a simple hub-and-spoke model that can be used with or without a VPC
  • AWS VPN CloudHub can be used if you have multiple branch offices and existing internet connections and would like to implement a convenient, potentially low cost hub-and-spoke model for primary or backup connectivity between these remote offices.
  • AWS VPN CloudHub leverages VPC virtual private gateway with multiple gateways, each using unique BGP autonomous system numbers (ASNs).

Transit VPC

  • A transit VPC is a common strategy for connecting multiple, geographically disperse VPCs and remote networks in order to create a global network transit center.
  • A transit VPC simplifies network management and minimizes the number of connections required to connect multiple VPCs and remote networks
  • Transit VPC can be used to support important use cases
    • Private Networking – You can build a private network that spans two or more AWS Regions.
    • Shared Connectivity – Multiple VPCs can share connections to data centers, partner networks, and other clouds.
    • Cross-Account AWS Usage – The VPCs and the AWS resources within them can reside in multiple AWS accounts.
  • Transit VPC design helps implement more complex routing rules, such as network address translation between overlapping network ranges, or to add additional network-level packet filtering or inspection.
  • Transit VPC
    • supports Transitive routing using the overlay VPN network — allowing for a simpler hub and spoke design. Can be used to provide shared services for VPC Endpoints, Direct Connect connection, etc.
    • supports network address translation between overlapping network ranges.
    • supports vendor functionality around advanced security (layer 7 firewall/Intrusion Prevention System (IPS)/Intrusion Detection System (IDS) ) using third-party software on EC2
    • leverages instance-based routing that increases costs while lowering availability and limiting the bandwidth.
    • Customers are responsible for managing the HA and redundancy of EC2 instances running the third-party vendor virtual appliance

Transit Gateway

Transit Gateway

  • is a highly available and scalable service to consolidate the AWS VPC routing configuration for a region with a hub-and-spoke architecture.
  • is a Regional resource and can connect VPCs within the same AWS Region.
  • TGWs across different regions can peer with each other to enable VPC communications within the same or different regions.
  • provides simpler VPC-to-VPC communication management over VPC Peering with a large number of VPCs.
  • enables you to attach VPCs (across accounts) and VPN connections in the same Region and route traffic between them.
  • support dynamic and static routing between attached VPCs and VPN connections
  • removes the need for using full mesh VPC Peering and Transit VPC

Hybrid Connectivity

AWS Network Connectivity Decision Tree

Virtual Private Network (VPN)

VPC Managed VPN Connection
  • VPC provides the option of creating an IPsec VPN connection between remote customer networks and their VPC over the internet
  • AWS managed VPN endpoint includes automated multi–data center redundancy & failover built into the AWS side of the VPN connection
  • AWS managed VPN consists of two parts
    • Virtual Private Gateway (VPG) on AWS side
    • Customer Gateway (CGW) on the on-premises data center
  • AWS Managed VPN only provides Site-to-Site VPN connectivity. It does not provide Point-to-Site VPC connectivity for e.g. from Mobile
  • Virtual Private Gateway are Highly Available as it represents two distinct VPN endpoints, physically located in separate data centers to increase the availability of the VPN connection.
  • High Availability on the on-premises data center must be handled by creating additional Customer Gateway.
  • AWS Managed VPN connections are low cost, quick to setup and start with compared to Direct Connect. However, they are not reliable as they traverse through Internet.

 

Software VPN

  • VPC offers the flexibility to fully manage both sides of the VPC connectivity by creating a VPN connection between your remote network and a software VPN appliance running in your VPC network.
  • Software VPNs help manage both ends of the VPN connection either for compliance purposes or for leveraging gateway devices that are not currently supported by Amazon VPC’s VPN solution.
  • Software VPNs allows you to handle Point-to-Site connectivity
  • Software VPNs, with the above design, introduces a single point of failure and needs to be handled.

Direct Connect – DX

  • AWS Direct Connect helps establish a dedicated private connection between an on-premises network and AWS.
  • Direct Connect can reduce network costs, increase bandwidth throughput, and provide a more consistent network experience than internet-based or VPN connections
  • Direct Connect uses industry-standard VLANs to access EC2 instances running within a VPC using private IP addresses
  • Direct Connect lets you establish
    • Dedicated Connection: A 1G, 10G, or 100G physical Ethernet connection associated with a single customer through AWS.
    • Hosted Connection: A 1G or 10G physical Ethernet connection that an AWS Direct Connect Partner provisions on behalf of a customer.
  • Direct Connect provides the following Virtual Interfaces
    • Private virtual interface – to access a VPC using private IP addresses.
    • Public virtual interface – to access all AWS public services using public IP addresses.
    • Transit virtual interface – to access one or more transit gateways associated with Direct Connect gateways.
  • Direct Connect connections are not redundant as each connection consists of a single dedicated connection between ports on your router and an Amazon router
  • Direct Connect High Availability can be configured using
    • Multiple Direct Connect connections
    • Back-up IPSec VPN connection

LAGs

  • Direct Connect link aggregation group (LAG) is a logical interface that uses the Link Aggregation Control Protocol (LACP) to aggregate multiple connections at a single AWS Direct Connect endpoint, allowing you to treat them as a single, managed connection.
  • LAGs need the following
    • All connections in the LAG must use the same bandwidth.
    • A maximum of four connections in a LAG. Each connection in the LAG counts toward the overall connection limit for the Region.
    • All connections in the LAG must terminate at the same AWS Direct Connect endpoint.

Direct Connect Gateway

  • is a globally available resource to enable connections to multiple VPCs across different regions or AWS accounts.
  • allows you to connect an AWS Direct Connect connection to one or more VPCs in the account that are located in the same or different regions
  • allows connecting any participating VPCs from one private VIF, reducing Direct Connect management.
  • can be created in any public region and accessed from all other public regions
  • can also access the public resources in any AWS Region using a public virtual interface.

References