Example: Juniper ScreenOS Device

The following diagram shows the general details of your customer gateway. Note that the VPN connection consists of two separate tunnels. Using redundant tunnels ensures continuous availability in the case that a device fails.

The diagram in this section illustrates an example Juniper ScreenOS customer gateway. Following the diagram, there is a corresponding example of the configuration information your integration team should provide. The example configuration contains information for each of the tunnels that you must configure.

In addition, the example configuration refers to these items that you must provide:

The example configuration includes several example values to help you understand how configuration works. For example, we provide example values for the VPN connection ID (vpn-44a8938f), virtual private gateway ID (vgw-8db04f81), the IP addresses (72.21.209.*, 169.254.255.*), and the remote ASN (7224). You'll replace these example values with the actual values from the configuration information that you receive.

In addition, you must:

In the following diagram and example configuration, you must replace the items in red italics with values that apply to your particular configuration.

# Amazon Web Services
# Virtual Private Cloud
#
# 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-44a8938f
# Your Virtual Private Gateway ID : vgw-8db04f81
# Your Customer Gateway ID        : cgw-b4dc3961
#
# This configuration consists of two tunnels. Both tunnels must be configured
# on your Customer Gateway.
#
# This configuration was tested on a Juniper SSG-5 running ScreenOS 6.3R2.
#
# --------------------------------------------------------------------------------
# IPsec Tunnel #1
# --------------------------------------------------------------------------------

 
# #1: Internet Key Exchange (IKE) Configuration
#
# A proposal is established for the supported IKE encryption, authentication,
# Diffie-Hellman, and lifetime parameters.
#

set ike p1-proposal ike-prop-vpn-44a8938f-1 preshare group2 esp aes128 sha-1 second 28800

# The IKE gateway is defined to be the Virtual Private Gateway. The gateway configuration
# associates a local interface, remote IP address, and IKE policy.
#
# This example shows the outside of the tunnel as interface ethernet0/0. This
# should be set to the interface that IP address YOUR_UPLINK_ADDRESS is
# associated with.
#
# This address is configured with the setup for your Customer Gateway. If the
# address changes, the Customer Gateway and VPN Connection must be recreated.
#

set ike gateway gw-vpn-44a8938f-1 address 72.21.209.225 id 72.21.209.225 main outgoing-interface ethernet0/0 preshare "plain-text-password1" proposal ike-prop-vpn-44a8938f-1

# Troubleshooting IKE connectivity can be aided by enabling IKE debugging.
# To do so, run the following commands:
# clear dbuf         -- Clear debug buffer
# debug ike all      -- Enable IKE debugging
# get dbuf stream    -- View debug messages
# undebug all        -- Turn off debugging

 
# #2: IPsec Configuration
#
# The IPsec (Phase 2) proposal defines the protocol, authentication,
# encryption, and lifetime parameters for our IPsec security association.
#

set ike p2-proposal ipsec-prop-vpn-44a8938f-1 group2 esp aes128 sha-1 second 3600
set ike gateway gw-vpn-44a8938f-1 dpd-liveness interval 10
set vpn IPSEC-vpn-44a8938f-1 gateway gw-vpn-44a8938f-1 replay tunnel proposal ipsec-prop-vpn-44a8938f-1

 
# #3: Tunnel Interface Configuration
#
# The tunnel interface is configured with the internal IP address.
#
# To establish connectivity between your internal network and the VPC, you
# must have an interface facing your internal network in the "Trust" zone.
#

set interface tunnel.1 zone Trust
set interface tunnel.1 ip 169.254.255.2/30
set interface tunnel.1 mtu 1436
set vpn IPSEC-vpn-44a8938f-1 bind interface tunnel.1

# By default, the router will block asymmetric VPN traffic, which may occur
# with this VPN Connection. This occurs, for example, when routing policies
# cause traffic to sent from your router to VPC through one IPsec tunnel
# while traffic returns from VPC through the other.
#
# This command allows this traffic to be received by your device.

set zone Trust asymmetric-vpn


# This option causes the router to reduce the Maximum Segment Size of TCP
# packets to prevent packet fragmentation.
#

set flow vpn-tcp-mss 1396


# #4: Border Gateway Protocol (BGP) Configuration
#
# BGP is used within the tunnel to exchange prefixes between the Virtual Private Gateway
# and your Customer Gateway. The Virtual Private Gateway will announce the prefix 
# corresponding to your VPC.
#
# Your Customer Gateway may announce a default route (0.0.0.0/0). 
#
# The BGP timers are adjusted to provide more rapid detection of outages.
#
# The local BGP Autonomous System Number (ASN) (YOUR_BGP_ASN) is configured
# as part of your Customer Gateway. If the ASN must be changed, the
# Customer Gateway and VPN Connection will need to be recreated with AWS.
#

set vrouter trust-vr
set max-ecmp-routes 2
set protocol bgp YOUR_BGP_ASN
set hold-time 30
set ipv4 network 0.0.0.0/0
# To advertise additional prefixes to Amazon VPC, copy the 'network' statement and  
# identify the prefix you wish to advertise (set network X.X.X.X/X). Make sure the  
# prefix is present in the routing table of the device with a valid next-hop. 
set ipv4 advertise-def-route
set enable
set neighbor 169.254.255.1 remote-as 7224
set neighbor 169.254.255.1 enable
set ipv4 neighbor 169.254.255.1 activate
exit
exit
set interface tunnel.1 protocol bgp			

# -------------------------------------------------------------------------
# IPsec Tunnel #2
# -------------------------------------------------------------------------

 
# #1: Internet Key Exchange (IKE) Configuration
#
# A proposal is established for the supported IKE encryption, authentication,
# Diffie-Hellman, and lifetime parameters.
#

set ike p1-proposal ike-prop-vpn-44a8938f-2 preshare group2 esp aes128 sha-1 second 28800

# The IKE gateway is defined to be the Virtual Private Gateway. The gateway configuration
# associates a local interface, remote IP address, and IKE policy.
#
# This example shows the outside of the tunnel as interface ethernet0/0. This
# should be set to the interface that IP address YOUR_UPLINK_ADDRESS is
# associated with.
#
# This address is configured with the setup for your Customer Gateway. If the
# address changes, the Customer Gateway and VPN Connection must be recreated.
#
set ike gateway gw-vpn-44a8938f-2 address 72.21.209.193 id 72.21.209.193 main outgoing-interface ethernet0/0 preshare "plain-text-password2" proposal ike-prop-vpn-44a8938f-2

# Troubleshooting IKE connectivity can be aided by enabling IKE debugging.
# To do so, run the following commands:
# clear dbuf         -- Clear debug buffer
# debug ike all      -- Enable IKE debugging
# get dbuf stream    -- View debug messages
# undebug all        -- Turn off debugging

 
# #2: IPsec Configuration
#
# The IPsec (Phase 2) proposal defines the protocol, authentication,
# encryption, and lifetime parameters for our IPsec security association.
#

set ike p2-proposal ipsec-prop-vpn-44a8938f-2 group2 esp aes128 sha-1 second 3600
set ike gateway gw-vpn-44a8938f-2 dpd-liveness interval 10
set vpn IPSEC-vpn-44a8938f-2 gateway gw-vpn-44a8938f-2 replay tunnel proposal ipsec-prop-vpn-44a8938f-2

 
# #3: Tunnel Interface Configuration
#
# The tunnel interface is configured with the internal IP address.
#
# To establish connectivity between your internal network and the VPC, you
# must have an interface facing your internal network in the "Trust" zone.

set interface tunnel.2 zone Trust
set interface tunnel.2 ip 169.254.255.6/30
set interface tunnel.2 mtu 1436
set vpn IPSEC-vpn-44a8938f-2 bind interface tunnel.2

# By default, the router will block asymmetric VPN traffic, which may occur
# with this VPN Connection. This occurs, for example, when routing policies
# cause traffic to sent from your router to VPC through one IPsec tunnel
# while traffic returns from VPC through the other.
#
# This command allows this traffic to be received by your device.

set zone Trust asymmetric-vpn

# This option causes the router to reduce the Maximum Segment Size of TCP
# packets to prevent packet fragmentation.

set flow vpn-tcp-mss 1396

 
# #4: Border Gateway Protocol (BGP) Configuration
#
# BGP is used within the tunnel to exchange prefixes between the Virtual Private Gateway
# and your Customer Gateway. The Virtual Private Gateway will announce the prefix 
# corresponding to your VPC.
#
# Your Customer Gateway may announce a default route (0.0.0.0/0).
#
# The BGP timers are adjusted to provide more rapid detection of outages.
#
# The local BGP Autonomous System Number (ASN) (YOUR_BGP_ASN) is configured
# as part of your Customer Gateway. If the ASN must be changed, the
# Customer Gateway and VPN Connection will need to be recreated with AWS.
#

set vrouter trust-vr
set max-ecmp-routes 2
set protocol bgp YOUR_BGP_ASN
set hold-time 30
set ipv4 network 0.0.0.0/0
# To advertise additional prefixes to Amazon VPC, copy the 'network' statement and  
# identify the prefix you wish to advertise (set network X.X.X.X/X). Make sure the  
# prefix is present in the routing table of the device with a valid next-hop. 
set ipv4 advertise-def-route
set enable
set neighbor 169.254.255.5 remote-as 7224
set neighbor 169.254.255.5 enable
set ipv4 neighbor 169.254.255.5 activate
exit
exit
set interface tunnel.2 protocol bgp

You must first test the gateway configuration for each tunnel.

When properly established, your BGP peering should be receiving one route from the virtual private gateway corresponding to the prefix that your VPC integration team specified for the VPC (for example, 10.0.0.0/24). If the BGP peering is established, you are receiving a prefix, and you are advertising a prefix, your tunnel is configured correctly. Make sure that both tunnels are in this state.

Next you must test the connectivity for each tunnel.

If your tunnels don't test successfully, see Troubleshooting Juniper ScreenOS Customer Gateway Connectivity.