Advanced/Enhanced Networking Interfaces Flashcards
Can EC2 instances have multiple ENIs?
Yes
If an EC2 instance has two ENIs, one primary and one secondary, which of the two can be detached and migrated to another EC2 instance?
Only the secondary. The primary ENI is permanently attached to the EC2 for the life of the EC2 instance. If the EC2 instance is deleted, that primary ENI (with it’s IP) is also deleted.
What are some use cases for multiple ENIs for one EC2 instance?
1) Multihoming interfaces to use for different roles that are in different subnets
2) Separate/isolate management subnets from production traffic on two separate ENIs
3) Application software licensing tied to one mac address can be attached to a secondary ENI for ease of detaching and moving the ENI to another EC2 instance
4) Used for low budget and high availablity b/c the secondary interface can be detached and moved to a backup EC2 instance
What are three main attributes of an ENI?
1) It attaches to an EC2 instance as a virtual network interface
2) By default, a private ipv4 address is attached to the ENI after creation of the ENI
3) Only one security group can be attached to one ENI
Can an ENI be moved to another availability zone?
No, it cannot. Primary and secondary ENIs can only reside in the same availability zone as it’s local EC2 instance.
What is SR-IOV?
SR-IOV is a method of device virtualization that provides higher I/O performance and lower CPU utilization
What networking virtualization is considered enhanced networking in AWS?
SR-IOV (single root input/output virtualization)
Is there an additional charge to use enhanced networking?
No
What are some of the attributes of SR-IOV?
1) High bandwidth
2) Low latency
3) Higher packet per second (pp) performance
What type of EC2 instance does not support enhanced networking?
T2
With SR-IOV, is traffic handled by a hypervisor?
No
True or false: SR-IOV is considered close to bare metal because there’s no hypervisor involved in traffic handling.
True
What is encompassed in 5-tuple properties?
1) source IP address
2) source port
3) destination IP address
4) destination port
5) protocol
How can you best describe 5-tuple?
Single flow communication between the source and destination devices.
What is the 5-tuple bandwidth speed between two hosts?
5 Gbps
What are the two types of network adapters (hint ENIs)?
1) Intel 82599 Virtual Function Interface
2) Elastic Network Adapter (ENA)
What is the maximum bandwidth of Intel 82599 Virtual Function Interface?
10 Gbps
What is the maximum bandwidth of Elastic Network Adapter (ENA)?
100 Gbps
In terms of network performance between EC2 instances, what is the intra-region bandwidth speeds for either Intel Virtual Function interface and ENA?
The maximum:
1) Intel - 10 Gbps
2) ENA - 100 Gpbs
In terms of network performance between EC2 instances, what is the inter-region bandwidth speeds for either Intel Virtual Function Interface and ENA?
Only a maximum:
1) Intel - 5 Gbps
2) ENA - 5 Gbps
In terms of traffic handling, what is SR-IOV considered as compared to using a hypervisor?
Pass-through because it does not go through a hypervisor
What is Elastic Fabric Adapter (EFA)?
Elastic Fabric Adapter (EFA) is a network interface for Amazon EC2 instances that enables customers to run applications requiring high levels of inter-node communications at scale. It is known as an OS bypass type of network interface.
Is Elastic Fabric Adapter enabled by default?
No, it’s an optional EC2 networking feature that can be enabled.
Is there an additional cost to using Elastic Fabric Adapter (EFA)?
No
What is the use case for enabling Elastic Fabric Adapter?
To enable high performance inter-instance communications for High Performance Computing (HPC) applications.
What OS can you use Elastic Fabric Adapter?
Linux
True or false: Windows OS can use either Elastic Fabric Adapter or Elastic Network Adapter.
False; it only uses the Elastic Network Adapter
What is a cluster placement group?
Packs instances close together inside an Availability Zone. This strategy enables workloads to achieve the low-latency network performance necessary for tightly-coupled node-to-node communication that is typical of high-performance computing (HPC) applications
What is a spread placement group?
This strictly places a small group of instances across distinct underlying hardware to reduce correlated failures.
If using a spread placement group, what is the instance limit?
7 instances
What is a partition placement group?
This spreads your instances across logical partitions such that groups of instances in one partition do not share the underlying hardware with groups of instances in different partitions. This strategy is typically used by large distributed and replicated workloads, such as Hadoop, Cassandra, and Kafka.
How many partitions are allowed if using a partition placement group?
7 partitions
How many instances are allowed in a partition placement group?
There is no limit
What is the biggest difference between spread and partition placement group?
Spread placement groups area managed by AWS. Partition placement groups are managed by the administrator of the aws account.
If using a HPC and machine learning application, which type of adapter should be used?
Elastic Fabric Adapter
Which placement group should be use for high performance cluster?
Cluster placement group
What is an Instance Metadata?
It is data about your instance that you can use to configure or manage the running instance.
What ip is used to access the instance metadata?
169.254.169.254
What is the URL to access the instance metadata?
http://169.254.169.254/latest/meta-data
Is access to an instance metadata secure?
No, there’s no authentication required to access an instance metadata.
What is the maximum MTU size supported in AWS?
Only within a vpc 9001
What is the command to check the path between two hosts?
Tracepath; used in the cli
What is network i/o credits?
This is the ability to burst beyond the baseline bandwidth for a limited time.
How are network i/o credits earned?
When a running instance uses less bandwidth than it’s baseline bandwidth.
What is DPDK?
Data plane development kit.
A set of libraries and NIC drivers for fast packet processing.
What is EBS provisioned IOPs?
Elastic Block Storage input/output operations per second
This is used for intensive workloads
How many EFAs (Elastic Fabric Adapter) can be assigned to an ENI?
Only one
