1.
© 2016, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
Becky Weiss, Senior Principal Engineer, EC2
Creating Your Virtual Data Center
VPC Fundamentals and Connectivity Options
NET201
November 30, 2016

2.
EC2 Instance

3.
172.31.0.128
172.31.0.129
172.31.1.24
172.31.1.27
54.4.5.6
54.2.3.4
VPC

4.
What to Expect from the Session
• Get familiar with VPC concepts
• Walk through a basic VPC setup
• Learn about the ways in which you
can tailor your virtual network to meet
your needs

5.
Walkthrough: setting up an
Internet-connected VPC

6.
Creating an Internet-connected VPC: steps
Choosing an
address range
Setting up subnets
in Availability Zones
Creating a route to
the Internet
Authorizing traffic
to/from the VPC

7.
Choosing an IP address range

8.
CIDR notation review
CIDR range example:
172.31.0.0/16
1010 1100 0001 1111 0000 0000 0000 0000

9.
Choosing an IP address range for your VPC
172.31.0.0/16
Recommended:
RFC1918 range
Recommended:
/16
(64K addresses)

10.
Subnets

11.
VPC subnets and Availability Zones
172.31.0.0/16
Availability Zone Availability Zone Availability Zone
VPC subnet VPC subnet VPC subnet
172.31.0.0/24 172.31.1.0/24 172.31.2.0/24
eu-west-1a eu-west-1b eu-west-1c

12.
VPC subnet recommendations
• /16 VPC (64K addresses)
• /24 subnets (251 addresses)
• One subnet per Availability Zone

13.
Route to the Internet

14.
Routing in your VPC
• Route tables contain rules for which
packets go where
• Your VPC has a default route table
• … but you can assign different route
tables to different subnets

15.
Traffic destined for my VPC
stays in my VPC

16.
Internet Gateway
Send packets here if you want
them to reach the Internet

17.
Everything that isn’t destined for the VPC:
Send to the Internet

18.
Network security in VPC:
Network ACLs / Security Groups

19.
Network ACLs: Stateless firewalls
English translation: Allow all traffic in
Can be applied on a subnet basis

20.
“MyWebServers” Security Group
“MyBackends” Security Group
Allow only “MyWebServers”
Security groups follow application structure

21.
Security groups example: web servers
In English: Hosts in this group are reachable
from the Internet on port 80 (HTTP)

22.
Security groups example: backends
In English: Only instances in the MyWebServers
Security Group can reach instances in this
Security Group

23.
Security groups in VPC: additional notes
• Follow the Principle of Least Privilege
• VPC allows creation of egress as well as ingress
Security Group rules
• Many application architectures lend themselves to a 1:1
relationship between security groups (who can reach
me) and IAM roles (what I can do).

24.
Connectivity options for VPCs

25.
Beyond Internet connectivity
Restricting Internet access
Connecting to your
corporate network
Connecting to other
VPCs

26.
Restricting Internet access:
Routing by subnet

27.
Routing by subnet
VPC subnet
VPC subnet
Has route to Internet
Has no route to Internet

28.
Outbound-only Internet access: NAT gateway
VPC subnet VPC subnet
0.0.0.0/0
0.0.0.0/0
Public IP: 54.161.0.39
NAT gateway

29.
Inter-VPC connectivity:
VPC peering

30.
Example VPC peering use:
shared services VPC
Common/core services
• Authentication/directory
• Monitoring
• Logging
• Remote administration
• Scanning

31.
Security groups across peered VPCs
VPC Peering
172.31.0.0/16 10.55.0.0/16
Orange Security Group Blue Security Group
ALLOW

32.
Establish a VPC peering: initiate request
172.31.0.0/16 10.55.0.0/16
Step 1
Initiate peering request

33.
Establish a VPC peering: accept request
172.31.0.0/16 10.55.0.0/16
Step 1
Initiate peering request
Step 2
Accept peering request

34.
Establish a VPC peering: create route
172.31.0.0/16 10.55.0.0/16Step 1
Initiate peering request
Step 2
Accept peering request
Step 3
Create routes
In English: Traffic destined for the
peered VPC should go to the peering

35.
Connecting to on-premises networks:
Virtual Private Network & Direct Connect

36.
Extend an on-premises network into your VPC
VPN
Direct Connect

37.
AWS VPN basics
Customer
Gateway
Virtual
Gateway
Two IPSec tunnels
192.168.0.0/16 172.31.0.0/16
192.168/16
Your networking device

38.
VPN and AWS Direct Connect
• Both allow secure connections
between your network and your VPC
• VPN is a pair of IPSec tunnels over
the Internet
• DirectConnect is a dedicated line with
lower per-GB data transfer rates
• For highest availability: Use both

39.
VPC and the rest of AWS

40.
VPC and the rest of AWS
AWS Services in
Your VPC
VPC Endpoints for
Amazon S3
DNS in-VPC with
Amazon Route 53
Logging VPC Traffic
with VPC Flow Logs

41.
AWS services in your VPC

42.
Example: Amazon RDS database in your VPC
Reachable via DNS Name: mydb-cluster-1
….us-west-2.rds.amazonaws.com

43.
Example: AWS Lambda function in your VPC

44.
Best practices for in-VPC AWS services
• Many AWS services support running in-VPC.
• Use security groups for Least-Privilege network access.
• For best availability, use multiple Availability Zones.
Examples:
• Multi-zone RDS deployments
• Use a zonal mount point for EFS access

45.
VPC Endpoints for Amazon S3

46.
S3 and your VPC
S3 Bucket
Your applications
Your data

47.
AWS VPC endpoints for S3
S3 Bucket

48.
AWS VPC endpoints for S3
S3 Bucket
Route S3-bound
traffic to the VPCE

49.
IAM policy for VPC endpoints
S3 Bucket
IAM Policy at VPC Endpoint:
Restrict actions of VPC in S3
IAM Policy at S3 Bucket:
Make accessible from
VPC Endpoint only

50.
DNS in a VPC

51.
VPC DNS options
Use Amazon DNS server
Have EC2 auto-assign DNS
hostnames to instances

52.
Amazon Route 53 private hosted zones
Private Hosted
Zone
example.demohostedzone.org 
172.31.0.99

53.
VPC Flow Logs:
VPC traffic metadata in Amazon
CloudWatch Logs

54.
VPC Flow Logs
Visibility into effects of security
group rules
Troubleshooting network
connectivity
Ability to analyze traffic

55.
VPC Flow Logs: setup
VPC traffic metadata captured in
CloudWatch Logs

56.
VPC Flow Logs data in CloudWatch Logs
Who’s this?
# dig +short -x 109.236.86.32
internetpolice.co.
REJECT
UDP Port 53 = DNS

57.
VPC: your private network in AWS

58.
The VPC network

59.
VPC network security

60.
VPC connectivity

61.
Thank you!

62.
Remember to complete
your evaluations!

63.
Related sessions
• NET303 - Next-Gen Networking: New Capabilities for
Amazon’s Virtual Private Cloud
• NET304 - Moving Mountains: Netflix’s Migration Into
VPC
• NET401 - Another Day, Another Billion Packets
• NET402 - Deep Dive: AWS Direct Connect and VPN
• NET404 - Making Every Packet Count