Amazon (SAP-C01) Exam Questions And Answers page 78

Amazon RDS allows you to use read replicas with Multi-AZ deployments. In Multi-AZ deployments for MySQL, Oracle, SQL Server, and PostgreSQL, the data in your primary DB Instance is synchronously replicated to to a standby instance in a different Availability Zone (AZ). Because of their synchronous replication, Multi-AZ deployments for these engines offer greater data durability benefits than do read replicas. (In all Amazon RDS for Aurora deployments, your data is automatically replicated across 3 Availability Zones.)
You can use Multi-AZ deployments and read replicas in conjunction to enjoy the complementary benefits of each. You can simply specify that a given Multi-AZ deployment is the source DB Instance for your Read replicas. That way you gain both the data durability and availability benefits of Multi-AZ deployments and the read scaling benefits of read replicas.
Note that for Multi-AZ deployments, you have the option to create your read replica in an AZ other than that of the primary and the standby for even more redundancy. You can identify the AZ corresponding to your standby by looking at the "Secondary Zone" field of your DB Instance in the AWS Management Console.

With Amazon EBS, you can use any of the standard RAID configurations that you can use with a traditional bare metal server, as long as that particular RAID configuration is supported by the operating system for your instance. This is because all RAID is accomplished at the software level. For greater I/O performance than you can achieve with a single volume, RAID 0 can stripe multiple volumes together; for on-instance redundancy, RAID 1 can mirror two volumes together. RAID 5 and RAID 6 are not recommended for Amazon EBS because the parity write operations of these RAID modes consume some of the IOPS available to your volumes.

AWS Direct Connect
AWS Direct Connect makes it easy to establish a dedicated network connection from your premises to AWS. Using AWS Direct Connect, you can establish private connectivity between AWS and your datacenter, office, or collocation environment, which in many cases can reduce your network costs, increase bandwidth throughput, and provide a more consistent network experience than Internet-based connections.
AWS Direct Connect lets you establish a dedicated network connection between your network and one of the AWS Direct Connect locations. Using industry standard 802.1q VLANs, this dedicated connection can be partitioned into multiple virtual interfaces. This allows you to use the same connection to access public resources such as objects stored in Amazon S3 using public IP address space, and private resources such as Amazon EC2 instances running within an Amazon Virtual Private Cloud (VPC) using private IP space, while maintaining network separation between the public and private environments. Virtual interfaces can be reconfigured at any time to meet your changing needs.
What is AWS Direct Connect?
AWS Direct Connect links your internal network to an AWS Direct Connect location over a standard 1 gigabit or 10 gigabit Ethernet fiber-optic cable. One end of the cable is connected to your router, the other to an AWS Direct Connect router. With this connection in place, you can create virtual interfaces directly to the AWS cloud (for example, to Amazon Elastic Compute Cloud (Amazon EC2) and Amazon Simple Storage Service (Amazon S3) and to Amazon Virtual Private Cloud (Amazon VPC), bypassing Internet service providers in your network path. An AWS Direct Connect location provides access to Amazon Web Services in the region it is associated with, as well as access to other US regions. For example, you can provision a single connection to any AWS Direct Connect location in the US and use it to access public AWS services in all US Regions and AWS GovCloud (US).
The following diagram shows how AWS Direct Connect interfaces with your network.

Requirements
To use AWS Direct Connect, your network must meet one of the following conditions:
Your network is collocated with an existing AWS Direct Connect location. For more information on available AWS Direct Connect locations, go to
You are working with an AWS Direct Connect partner who is a member of the AWS Partner Network (APN). For a list of AWS Direct Connect partners who can help you connect, go to http://aws.amazon.com/directconnect.
You are working with an independent service provider to connect to AWS Direct Connect.
In addition, your network must meet the following conditions:
Connections to AWS Direct Connect require single mode fiber, 1000BASE-LX (1310nm) for 1 gigabit Ethernet, or 10GBASE-LR (1310nm) for 10 gigabit Ethernet. Auto Negotiation for the port must be disabled. You must support 802.1Q VLANs across these connections.
Your network must support Border Gateway Protocol (BGP) and BGP MD5 authentication. Optionally, you may configure Bidirectional Forwarding Detection (BFD).
To connect to Amazon Virtual Private Cloud (Amazon VPC), you must first do the following:
Provide a private Autonomous System Number (ASN). Amazon allocates a private IP address in the 169.x.x.x range to you.
Create a virtual private gateway and attach it to your VPC. For more information about creating a virtual private gateway, see Adding a Hardware Virtual Private Gateway to Your VPC in the Amazon VPC User Guide.
To connect to public AWS products such as Amazon EC2 and Amazon S3, you need to provide the following:
A public ASN that you own (preferred) or a private ASN.
Public IP addresses (/31) (that is, one for each end of the BGP session) for each BGP session. If you do not have public IP addresses to assign to this connection, log on to AWS and then open a ticket with AWS Support.
The public routes that you will advertise over BGP.

In Amazon EFS, when a file system and mount targets are created in your VPC, you can mount the remote file system locally on your Amazon Elastic Compute Cloud (EC2) instance. You can grant permissions to the users of your file system. The initial permissions mode allowed for Amazon EFS are:
• read-write-execute permissions to the owner root
• read-execute permissions to the group root read-execute permissions to others

If you create a VPN connection, you must specify the type of routing that you plan to use, which will depend upon on the make and model of your VPN devices. If your VPN device supports Border Gateway Protocol (BGP), you need to specify dynamic routing when you configure your VPN connection. If your device does not support BGP, you should specify static routing.