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Flashcard 4456289537292

Question

In AWS, you can think of a [...] as your own private data centre (LAN) in the cloud.

Answer

VPC

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Reich et al. (13) present a thorough comparison of prediction skills across seasons and US regions, shedding light on how forecasting performances vary with geography. Some regions appear more difficult to predict than others (e.g., a null model based on historical averages does poorly, indicating large interannual variability in ILI incidences). In contrast, other regions are easier to predict due to greater stability in observed historical patterns and substantial improvement of predictive models over historical averages. Moving forward, it will be important to understand whether regional differences in predictive skills are a reporting artifact or whether they reflect heterogeneities in influenza transmission dynamics. Demographic and environmental differences among regions, connectivity, and spatial extent could all affect predictive skills. This question could have practical implications because regions displaying consistently high predictive power could be used as sentinels for influenza surveillance.

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Annotation 4595404115212

For the same basic reproductive ratio and average infectious period larger values of the Gamma distribution parameter n lead to a steeper increase in prevalence and an epidemic of shorter duration.

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Annotation 4596694650124

The greatest challenge—and the greatest prize—in modeling emerging zoonoses is to assess which diseases pose the most risk to humans and how these might change over time and in different localities (24). Such tasks, which will join molecular studies to experimental infections to epidemiological and ecological surveys, will drive empirical and theoretical efforts for decades to come.

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Annotation 4600515398924

Chart choice/selection

With the exception of the trellis and the block chart, you will find that whenever you are thinking of using any of the charts (radar, mekko, funnel, or grid), there is usually a better solution that uses a bar, line, or scatter chart

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Annotation 4600519593228

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Flashcard 4600526146828

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Flashcard 4600535059724

Question

In AWS, a VPC consists the following core elements: [...] , Route Tables, NACLs (Network Access Control Lists), Security Groups, and various Gateways (Internet Gateways/Virutal Private Gateways, NATs, etc).

Answer

Subnets

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Flashcard 4600537156876

Question

In AWS, a VPC consists the following core elements: Subnets, [...] [...] s, NACLs (Network Access Control Lists), Security Groups, and various Gateways (Internet Gateways/Virutal Private Gateways, NATs, etc).

Answer

Route Tables

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Flashcard 4600539254028

Question

In AWS, a VPC consists the following core elements: Subnets, Route Tables, [...] [...] [...] [...] s, Security Groups, and various Gateways (Internet Gateways/Virutal Private Gateways, NATs, etc).

Answer

Network Access Control Lists

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Flashcard 4600541351180

Question

In AWS, a VPC consists the following core elements: Subnets, Route Tables, NACLs (Network Access Control Lists), [...] [...] , and various Gateways (Internet Gateways/Virutal Private Gateways, NATs, etc).

Answer

Security Groups

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Flashcard 4600543448332

Question

In AWS, a VPC consists the following core elements: Subnets, Route Tables, NACLs (Network Access Control Lists), Security Groups, and various [...] .

Answer

Gateways (Internet Gateways/Virutal Private Gateways, NATs, etc)

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Flashcard 4600545545484

Question

In AWS, each region usually has a [...] VPC, and on top of that you can then creat your own additional [...] VPCs <--- Two different answers for each occulsion

Answer

Default / Custom

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Flashcard 4600547642636

Question

In AWS, for each region, the Default VPC has a public subnet in each [...] [...]

Answer

Availability Zone

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Flashcard 4600549739788

Question

In AWS, for each region, the Default VPC has a [...] subnet in each availability zone

Answer

public

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Flashcard 4600551836940

Question

In AWS, for each region, the Default VPC has a default NACL (Network Access Control List), what are the inbound and outbound rules of that NACL?

Answer

It allows all traffic (for all ports, all IPs) for inbound and outbound

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Flashcard 4600553934092

Question

In AWS, for each region, the Default VPC has a default SG, what are the inbound and outbound rules of that SG

Answer

Allows all traffic out (on all ports) but only allows all traffic in (for all ports) from instances attached to the same SG (i.e. default SG), so allows instances attached to the SG to talk to each other on inbound

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Flashcard 4600556031244

Question

In AWS, when you create a new Custom VPC, by default the following resources/elements are created: [...] , [...] , and [...] <-- each occultion is a differnent entity, so could be multiword/acronym answer

Answer

Route Table, Network Access Contorl List, and Security Group

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Flashcard 4600558128396

Question

In AWS, when you create a new Custom VPC, one of the first things you do is select the [...] range for the instances that will go within the VPC. <-- bonus: think of an example range you would assign

Answer

CIDR (i.e. IP)

^^ (e.g. 10.0.0.0/16).

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Flashcard 4600560225548

Question

In AWS, and in networking in general, corporate networks/LANs have an intenal IP range of [...] / [...]

Answer

10.0.0.0/8

^^ but AWS only allows ranges of /16 to /28, so for VPC you would have a range of 10.0.0.0/16
^^^ for personal networks it is 192.168.0.0/16

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Flashcard 4600562322700

Question

In AWS, when you create a new custom VPC and select the CIDR range (i.e. private IP range for the instances that will go in the VPC), the range is between /[...] to /[...] <--bonus thing of what the implication of this range are as far as how many internal IPs you can have in the VPC.

Answer

/16 and /28

^^ so you can have max of 65536 (2^16), min of 16 (32-28=4, 2^4=16) internal/private IPs in your VPC
^^^ note you can add additional CIDR ranges on top later

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Flashcard 4600564419852

Question

In AWS, when you create a custom VPC and then try to create a subnet in it, you have to select one particular [...] [...] to place the subnet in.

Answer

Availability Zone

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Flashcard 4600566517004

Question

In AWS, after you create a new Custom VPC, you create one or more subnets (that you put in the VPC). When you select the CIDR range for the subnet (i.e. IP range for the private IPs of instances within the subnet), the following 2 rules must be followed: the CIDR range must be [...] and not overlap with the CIRD range of any existing subnet in the same VPC

Answer

subset of the VPC CIDR range

^^ e.g. if CIRD range of VPC is 10.0.0.0/16, and VPC has 2 sunbets, the ranges can be for e.g. 10.0.1.0/24 and 10.0.2.0/24

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Flashcard 4600568614156

Question

Answer

not overlap with the CIRD range of any existing subnet in the same VPC

^^ e.g. if CIRD range of VPC is 10.0.0.0/16, and VPC has 2 sunbets, the ranges can be for e.g. 10.0.1.0/24 and 10.0.2.0/24

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Flashcard 4600570711308

Question

In AWS, if you create a custom VPC with CIDR range of 10.0.0.0/16, and you want to create two subnets within this VPC, what ranges would you select for the two subnets (I know answer can vary but think of most obvious/elegant example for the answer).

Answer

10.0.1.0/24 and 10.0.2.0/24

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Flashcard 4600572808460

Question

In AWS, when you create a subnet in a VPC, with a CIDR range you select for the subnet, AWS reserves the first [...] and last [...] IPs in the range, so those are not avialable for your instances to have as their private IPs <-- different answer for each occulsion

Answer

first 4 and last 1

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Flashcard 4600574905612

Question

In AWS, what makes a subnet within a VPC private vs public, is the absence or presence, respectively, of a route to an [...] [...] in the route table associated with that subnet.

Answer

Internet Gateway

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Flashcard 4600577002764

Question

In AWS, when you create a new custom VPC and then create a new subnet within that VPC, what are the 3 main steps to make that subnet public (steps 1 and 2 are very closely related)?

Answer

1) Create an IGW

2) attach it to VPC

3) configure Route table for your subnet to direct internet bound traffic to your IGW (e.g. Destination: 0.0.0.0/0 to Target: IGW ID)

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Flashcard 4600579099916

Question

In AWS, for VPCs, each subnet is associated with a Route Table (for routing traffic within the VPC and externally), the Route Table has routs that have a [...] column and a [...] column <-- Two different occusions

Answer

Destination / Target

^^ e.g. 1 you can have a route where destination is 0.0.0.0/0 and target is igw-id to route traffic to IGW for public subnet
^^^ e.g. 2 you can have a route where Destination is 10.0.0.0/16 (VPC CIDR range) and Target is "local", to route internal traffic within the VPC

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Flashcard 4600581197068

Question

In AWS, for VPCs, the Route Table (that routs traffic within the VPC and externally), has routes with a Destination value and a Target value, give an example of what a route would look like for the Main (which is the default) route table where the VPC CIDR range is 10.0.0.0/16

Answer

Destination is 10.0.0.0/16 and Target is "local"

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Flashcard 4600583294220

Question

In AWS, for VPCs, the Route Table (that routs traffic within the VPC and externally), has routes with a Destination value and a Target value, give an example of what a route would look like for a Route Table that is associated with a public subnet (i.e. the route that makes the subnet public), assuming you have an Internet Gateway attached to your VPC with id: igw-5e4d5238

Answer

Destination is 0.0.0.0/0 and Target is igw-5e4d5238

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Flashcard 4600585391372

Question

In AWS, each VPC can have [...] IGW (Internet Gateway) attached to it

Answer

^^ ONLY 1

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Flashcard 4600587488524

Question

In AWS, for VPCs, any subnet that is not explicitly associated with a custom Route Table, is implicitly associated with the [...] route table

Answer

Main

^^ the main route table initially just has a route of Destination=VPC CIDR range, and Target=local, to route traffic within the VPC

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Flashcard 4600591944972

Question

In AWS, for VPCs, when you add a route in your route table to direct traffic to IGW (Internet Gateway), you do it in a custom route table (not the Main one) and attach the Route Table to your public subnet(s). Why do you not add the route to your Main route table?

Answer

If you add the route to your IGW in the main Route Table, then all new subnets that get created are by default associated with the Main Route Table so they become public subnets by default which is security risk.

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Flashcard 4600594042124

Question

In AWS, for VPCs, if you want instances that go inside your public subnet to get public IPs assigned automatically, you need to enable Auto assign public IPv4 for your subnet (which is disabled by default). This setting can then be overruled when you create your [...] [...] to place in your subnet.

Answer

EC2 Instance

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Flashcard 4600601120012

Question

In AWS, and networking in general, NAT stands for [...] [...] [...]

Answer

Network Address Translation

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Flashcard 4600603217164

Question

In AWS, and networking in general, what does a NAT (Network Address Translation) device do?

Answer

It is a device that translates private IPs to public IPs so your LAN devices can talk to internet

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Flashcard 4600605314316

Question

In AWS, for VPCs, if you want your instances within your private subnet (for example your DB server) to still be able to make outbound calls to the internet (for example for software installs/updates) but you don't want the instances to be reachable by outside/internet initiated calls, you can achieve this by using a [...] [...]

Answer

NAT Gateway (or NAT Instance)

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Flashcard 4600607411468

Question

In AWS, for VPCs, what is the purpuse of a NAT Instance/Gateway? (be as specific as possible)

Answer

NAT instance/gateway is way for your instances in your private subnet to make outbound calls to internet (for example for your db server to downloading software updates) without having the instance be reachable from an outside initiated call (security measure).

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Flashcard 4600610032908

Question

In AWS, for VPCs, a NAT instance/gateway is way for your instances in your private subnet to make outbound calls to internet (for example for your db server to downloading software updates) without having the instance be reachable from an [...] initiated call

Answer

outside/internet

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Flashcard 4600612130060

Question

In AWS, for VPCs, instance in private subnet (that only has private IPs), goes to [...] instance/gateway, which is in public subnet and has a public IP, which can then route the traffic to internet (via IGW) and through to the internet.

Answer

NAT (Network Address Translation)

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Flashcard 4600615800076

Question

In AWS, for VPCs, instance in private subnet (that only has private IPs), goes to NAT instance/gateway, which is in [...] subnet and has a [...] IP, which can then route the traffic to internet (via IGW) and through to the internet. <- same answer for both occulsions

Answer

Public

^^ so basically the NAT translates the private IP of the instance in the private subnet to its own public IP for the request to the internet and the for the response does the opposite (i.e. translates the public IP of itself to the private IP of the instance that initiated the request). It can do this for all the various different internal IPs of all the different private Subnet instances via some fancy port trickery.

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Flashcard 4600617897228

Question

In AWS, for VPC, if you want your private sunbet instances to talk to internet (e.g. for your DB server to download software) without having the instance open to inbound internet initiated calls, you use NAT, which has two variants. NAT [...] is an EC2 that you manage yourself (it is made from a special AMI) while NAT [...] are managed by AWS and more highly available/with better bandwith constraints. <- two different answers for each occulsion

Answer

Instance / Gateway

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Flashcard 4600619994380

Question

Answer

NAT instance is a single EC2 instance that you manage yourself (it is made from a special AMI) while NAT gateway are managed by AWS and more highly available/with better bandwith constraints.

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Flashcard 4600622091532

Question

In AWS, for VPC, if you want your private sunbet instances to talk to internet (e.g. for your DB server to download software) without having the instance open to inbound internet calls, you can use NAT instance or NAT gateway. If you choose NAT instance (which requires much more management on your part), you need to disable source/destination check (by default all EC2 instances have this check enabled). What is this source/destination check and why do you need to disable it for NAT instance?

Answer

source/destination check (enabled by default for EC2 instances) is to make sure the instance is the final source/destination of all outgoing/incoming packets but since NAT is a passthrough we need to disable this check.

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Flashcard 4600624188684

Question

In AWS, for VPC, for both NAT instance and gateway, to make them useful (in providing instances in private subnet ability to talk to internet for software updates but not allow outside initiated inbound calls), what step do you need to take after creating the NAT instance/gateway?

Answer

you need to configure route in route table for your private subnet (or you can use default/main subnet) to point internet bound traffic (Destination = 0.0.0.0/0) to the NAT instance/gateway (Target = NAT instance/gateway id).

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Flashcard 4600626285836

Question

In AWS, for VPC, when you create NAT gateway (to provide instances in private subnet ability to talk to internet for software updates but not allow outside initiated inbound calls), you must select a single [...] within your VPC to put it in and you create a new Elastic IP to use with it

Answer

Subnet

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Flashcard 4600628382988

Question

In AWS, for VPC, when you create NAT gateway (to provide instances in private subnet ability to talk to internet for software updates but not allow outside initiated inbound calls), you must select a single subnet within your VPC to put it in and you create a new [...] [...] to use with it

Answer

Elastic IP

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Flashcard 4600630480140

Question

In AWS, for VPCs, when you create NAT gateway (to provide instances in private subnet ability to talk to internet for software updates but not allow outside initiated inbound calls), for proper HA, you should create a NAT Gatway in a subnet within each Availabiliy Zone, and route traffic from private subnet in the same Availablity Zone to the corresponding NAT Gateway in the same AZ. Why do you need to do this?

Answer

So if one AZ goes down, internet access is not disrupted to instances in private subnet in totally seperate AZ.

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Edited, memorised or added to reading queue

on 22-Nov-2019 (Fri)

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