IPSec VPN between LTM and AWS VPC

This is the Generic Description from the "Download Configuration" Button

Amazon Web Services
Virtual Private Cloud

VPN Connection Configuration
================================================================================
AWS utilizes unique identifiers to manipulate the configuration of 
a VPN Connection. Each VPN Connection is assigned a VPN Connection Identifier 
and is associated with two other identifiers, namely the 
Customer Gateway Identifier and the Virtual Private Gateway Identifier.

Your VPN Connection ID               : vpn-abcdefgh
Your Virtual Private Gateway ID          : vgw-abcdefgh
Your Customer Gateway ID             : cgw-abcdefgh

A VPN Connection consists of a pair of IPSec tunnel security associations (SAs). 
It is important that both tunnel security associations be configured. 


IPSec Tunnel 1
================================================================================
1: Internet Key Exchange Configuration

Configure the IKE SA as follows
  - Authentication Method    : Pre-Shared Key 
  - Pre-Shared Key           : abcdefghijklmnopqrstuvwxyz
  - Authentication Algorithm : sha1
  - Encryption Algorithm     : aes-128-cbc
  - Lifetime                 : 28800 seconds
  - Phase 1 Negotiation Mode : main
  - Perfect Forward Secrecy  : Diffie-Hellman Group 2

2: IPSec Configuration

Configure the IPSec SA as follows:
  - Protocol                 : esp
  - Authentication Algorithm : hmac-sha1-96
  - Encryption Algorithm     : aes-128-cbc
  - Lifetime                 : 3600 seconds
  - Mode                     : tunnel
  - Perfect Forward Secrecy  : Diffie-Hellman Group 2

IPSec Dead Peer Detection (DPD) will be enabled on the AWS Endpoint. We
recommend configuring DPD on your endpoint as follows:
  - DPD Interval             : 10
  - DPD Retries              : 3

IPSec ESP (Encapsulating Security Payload) inserts additional
headers to transmit packets. These headers require additional space, 
which reduces the amount of space available to transmit application data.
To limit the impact of this behavior, we recommend the following 
configuration on your Customer Gateway:
  - TCP MSS Adjustment       : 1387 bytes
  - Clear Don't Fragment Bit : enabled
  - Fragmentation            : Before encryption

3: Tunnel Interface Configuration

Your Customer Gateway must be configured with a tunnel interface that is
associated with the IPSec tunnel. All traffic transmitted to the tunnel
interface is encrypted and transmitted to the Virtual Private Gateway.



The Customer Gateway and Virtual Private Gateway each have two addresses that relate
to this IPSec tunnel. Each contains an outside address, upon which encrypted
traffic is exchanged. Each also contain an inside address associated with
the tunnel interface.

The Customer Gateway outside IP address was provided when the Customer Gateway
was created. Changing the IP address requires the creation of a new
Customer Gateway.

The Customer Gateway inside IP address should be configured on your tunnel
interface. 

Outside IP Addresses:
  - Customer Gateway                : 1xxxxxxxxxxx
  - Virtual Private Gateway         : 87.238.85.42

Inside IP Addresses
  - Customer Gateway                : 169.254.254.2/30
  - Virtual Private Gateway             : 169.254.254.1/30

Configure your tunnel to fragment at the optimal size:
  - Tunnel interface MTU     : 1436 bytes


4: Static Routing Configuration:

To route traffic between your internal network and your VPC, 
you will need a static route added to your router.

Static Route Configuration Options:

  - Next hop       : 169.254.254.1

You should add static routes towards your internal network on the VGW.
The VGW will then send traffic towards your internal network over 
the tunnels.  



IPSec Tunnel 2
================================================================================
1: Internet Key Exchange Configuration

Configure the IKE SA as follows
  - Authentication Method    : Pre-Shared Key 
  - Pre-Shared Key           : abcdefghijklmnopqrstuvwxyz
  - Authentication Algorithm : sha1
  - Encryption Algorithm     : aes-128-cbc
  - Lifetime                 : 28800 seconds
  - Phase 1 Negotiation Mode : main
  - Perfect Forward Secrecy  : Diffie-Hellman Group 2

2: IPSec Configuration

Configure the IPSec SA as follows:
  - Protocol                 : esp
  - Authentication Algorithm : hmac-sha1-96
  - Encryption Algorithm     : aes-128-cbc
  - Lifetime                 : 3600 seconds
  - Mode                     : tunnel
  - Perfect Forward Secrecy  : Diffie-Hellman Group 2

IPSec Dead Peer Detection (DPD) will be enabled on the AWS Endpoint. We
recommend configuring DPD on your endpoint as follows:
  - DPD Interval             : 10
  - DPD Retries              : 3

IPSec ESP (Encapsulating Security Payload) inserts additional
headers to transmit packets. These headers require additional space, 
which reduces the amount of space available to transmit application data.
To limit the impact of this behavior, we recommend the following 
configuration on your Customer Gateway:
  - TCP MSS Adjustment       : 1387 bytes
  - Clear Don't Fragment Bit : enabled
  - Fragmentation            : Before encryption

3: Tunnel Interface Configuration

Your Customer Gateway must be configured with a tunnel interface that is
associated with the IPSec tunnel. All traffic transmitted to the tunnel
interface is encrypted and transmitted to the Virtual Private Gateway.



The Customer Gateway and Virtual Private Gateway each have two addresses that relate
to this IPSec tunnel. Each contains an outside address, upon which encrypted
traffic is exchanged. Each also contain an inside address associated with
the tunnel interface.

The Customer Gateway outside IP address was provided when the Customer Gateway
was created. Changing the IP address requires the creation of a new
Customer Gateway.

The Customer Gateway inside IP address should be configured on your tunnel
interface. 

Outside IP Addresses:
  - Customer Gateway                : 1xxxxxxxxxxx
  - Virtual Private Gateway         : 87.238.85.46

Inside IP Addresses
  - Customer Gateway                : 169.254.254.6/30
  - Virtual Private Gateway             : 169.254.254.5/30

Configure your tunnel to fragment at the optimal size:
  - Tunnel interface MTU     : 1436 bytes


4: Static Routing Configuration:

To route traffic between your internal network and your VPC, 
you will need a static route added to your router.

Static Route Configuration Options:

  - Next hop       : 169.254.254.5

You should add static routes towards your internal network on the VGW.
The VGW will then send traffic towards your internal network over 
the tunnels.  




Additional Notes and Questions
================================================================================

  - Amazon Virtual Private Cloud Getting Started Guide: 
      http://docs.amazonwebservices.com/AmazonVPC/latest/GettingStartedGuide
  - Amazon Virtual Private Cloud Network Administrator Guide: 
      http://docs.amazonwebservices.com/AmazonVPC/latest/NetworkAdminGuide
  - XSL Version: 2009-07-15-1119716