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Manual: BIG-IP Secure IPsec Tunneling: From a Data Center Network to a Microsoft Azure Network
Manual

Original Publication Date: 08/08/2016
Updated Date: 12/01/2016

Overview: Using IPsec on the BIG-IP system to establish a secure network

This document guides you through the steps to configure a site-to-site (S2S) VPN tunnel connection from a corporate data center to an Microsoft Azure virtual network (VNet).

Watch an overview of BIG-IP IPsec tunneling and how to set up a secure tunnel to an Azure virtual network

Before you can set up a S2S VPN tunnel, you need to create a virtual network, gateway subnet in Azure, and complete other Azure VPN configuration steps. These are all beyond the scope of this document. For details, see Create a VNet with a Site-to-Site connection using PowerShell at https://azure.microsoft.com/en-us/documentation/articles/vpn-gateway-create-site-to-site-rm-powershell/

Sample configuration of a corporate data center and Azure resource groups connected by an IPsec site-to-site VPN tunnel

This illustration shows:

  • A corporate data center, which includes a BIG-IP® VE and is where databases live.
  • An Azure resource group, which contains a VNet. This VNet acts as a central hub for taking care of routing out to additional subnets.
  • Additional Azure resource groups, which host applications and appliances.

In order for the databases in the corporate data center to contact the applications in Azure, you need to set up a VPN tunnel between the BIG-IP VE and Azure VNet.

How do I set up a secure tunnel to an Azure virtual network?

You should follow all of the tasks in this document, in the order shown.

Define an IKE Phase 2 security policy

Use these steps to configure the Internet Key Exchange (IKE) Phase 2 settings (authentication & encryption algorithms and perfect forward secrecy) for tunnel traffic.

In case you are not familiar with IKE, IKE Phase 2 is where security associations (a set of policy and key[s] used to protect information) are negotiated on behalf of services such as IPsec, or any other service that needs key material and/or parameter negotiation.

Watch how to define an IKE Phase 2 security policy

  1. On the Main tab, click Network > IPsec > IPsec Policies.
    The IPsec Policies screen opens.
  2. Click the Create button.
    The New Policy screen opens.
  3. Configure the settings described in this table. For all other settings, use the defaults.
    Section Setting Details
    General Properties Name Type a unique name for the IPsec policy, such as my_ipsec_policy.
    Configuration Mode Select IPsec Interface.
    IKE Phase 2 Authentication Algorithm Select SHA-1.
    IKE Phase 2 Encryption Algorithm Select AES-256.
    IKE Phase 2 Perfect Forward Secrecy Select MODP1024.
  4. Click Finished.
    The screen refreshes and displays the new IPsec policy in the list.

Define eligible web traffic for the secure tunnel

Use these steps to direct web traffic into the secure tunnel.

The traffic selector (a packet filter that defines which traffic should be handled by an IPsec policy) filters traffic based on the IP addresses and port numbers that you specify, as well as the custom IPsec policy you assign.

Watch how to define eligible web traffic for the secure tunnel

  1. On the Main tab, click Network > IPsec > Traffic Selectors.
    The Traffic Selector screen opens.
  2. Click Create.
    The New Traffic Selector screen opens.
  3. Configure the settings described in this table. For all other settings, use the defaults.
    Section Setting Details
    General Properties Name Type a unique name for the traffic selector, such as my_traffic_selector.
    General Properties Order Specify the order in which traffic is matched. For example, select Specify and type 1.
    Configuration Source IP Address or CIDR Type the host or network address from which the application traffic originates. For example, 192.168.60.0/24.
    Configuration Destination IP Address or CIDR Type the final host or network address to which the application traffic is destined. For example, 172.16.101.0/24.
    Configuration IPsec Policy Name Select the name of the IPsec policy that you created. For example, my_ipsec_policy.
  4. Click Finished.
    The screen refreshes and displays the new IPsec traffic selector in the list.

Define IKE Phase 1 tunnel negotiation parameters

Use these steps to configure negotiation to authenticate Internet Key Exchange (IKE) peers and to encrypt IKE communication.

During IKE Phase 1, IKE peers, a configuration object of the IPsec protocol that represents a BIG-IP® system on each side of the IPsec tunnel, allow two systems to authenticate each other.

Watch how to define IKE Phase 1 tunnel negotiation parameters

  1. On the Main tab, click Network > IPsec > IKE Peers.
    The IKE Peers screen opens.
  2. Click the Create button.
    The New IKE Peer screen opens.
  3. Configure the settings described in this table. For all other settings, use the defaults.
    Section Setting Details
    General Properties Name Type a unique name for the IKE peer, such as my_ike_peer.
    General Properties Remote Address Type the IP address of the device that is remote to the system you are configuring. For example, 198.51.100.1.
    General Properties Version Select the Version 2 check box.
    IKE Phase 1 Algorithms Encryption Algorithm Select AES256.
    IKE Phase 1 Credentials Authentication Method Select Preshared Key.
    IKE Phase 1 Credentials Preshared Key and Verify Preshared Key Type a string that the IKE peers share for authenticating each other.
    Common Settings Traffic Selector Under the Available setting, select a Traffic Selector, and move it under Selected. For example, select and move my_traffic_selector.
    Common Settings Presented ID Value Type the IP address for Override For example, 192.0.2.1.
    Common Settings Verified ID Value Type the IP address for Override For example, 198.51.100.1.
  4. Click Finished.
    The screen refreshes and displays the new IKE peer in the list.

Create a virtual interface for routing traffic through the tunnel

Use these steps to create an IPsec interface profile to filter traffic through the tunnel according to the traffic selector you specify.

The parent profile specifies the profile from which the newly created profile inherits settings.

Watch how to create a virtual interface for routing traffic through the tunnel

  1. On the Main tab, click Network > Tunnels > Profiles > IPsec Interface.
    The IPsec Interface screen opens.
  2. Click the Create button.
    The New Policy screen opens.
  3. In the Name field, type a unique name for the profile, such as my_ipsec_profile.
  4. From the Parent Profile list, retain the default selection, ipsec.
  5. On the right side of the screen, select the Custom check box.
  6. In the Settings area, from the Traffic Selector list, select the traffic selector for the IPsec interface tunnel to which the profile is applied, such as my_traffic_selector.
  7. Click Finished.
    The screen refreshes and displays the new IPsec policy in the list.

Create a tunnel by assigning endpoints and direction

Use these steps to create an IPsec tunnel on the BIG-IP® system and specify how the tunnel carries traffic.

When configuring a new tunnel, the default setting for Mode is Bidirectional, but this document only describes how to set up a tunnel for outbound traffic; that is, IPsec tunneling from a corporate data center network to a Microsoft Azure network.

Watch how to create a tunnel by assigning endpoints and direction

  1. On the Main tab, click Network > Tunnels > Tunnel List > Create.
    The New Tunnel screen opens.
  2. Configure the settings described in this table. For all other settings, use the defaults.
    Setting Details
    Name Type a unique name for the tunnel, such as my_tunnel.
    Profile Select the profile associated with the tunnel for handling traffic, such as my_ipsec_profile.
    Local Address Type the IP address of the local endpoint of the tunnel. For example, 192.0.2.1.
    Remote Address Type the IP address of the remote endpoint of the tunnel. For example, 198.51.100.1.
  3. Click Finished.
    The screen refreshes and displays the new tunnel in the list.

Create IP addresses for local and remote tunnel endpoints

Before starting, make sure you have created a tunnel.
Use these steps to create tunnel endpoints. You start by first creating a tunnel local endpoint and then repeat the steps a second time to create a tunnel remote endpoint.

Watch how to create IP addresses for local and remote tunnel endpoints

  1. On the Main tab, click Network > Self IPs.
    The Self IP screen opens.
  2. Click Create.
    The New Self IP screen opens.
  3. Configure the settings described in this table. For all other settings, use the defaults.
    Setting Details
    Name Type a unique name for the self IP address, such as my_self_ip.
    IP Address Type the IP address of the tunnel local endpoint. For example, 192.0.2.1.
    Netmask Type the netmask for the specified IP address. For example, 255.255.255.0.
    Port Lockdown Select Allow All.
  4. Click Finished.
    The screen refreshes, and displays the new self IP address in the list.
  5. Repeat the previous steps, but this time type a name and an IP address for a remote tunnel endpoint. For example, you can type my_ipesec_tunnel, and 10.23.54.2. When repeating the steps, for the VLAN/Tunnel setting, select the name of the tunnel you created, such as my_tunnel. The first time through, for the VLAN/Tunnel setting, you retained the default setting (External).

Add a static route for web traffic

Before you start this task, make sure you've created a tunnel and have assigned a self IP address to the tunnel.

Use these steps to route traffic from a BIG-IP system to an Azure virtual network and to specify the virtual interface as the gateway for the route.

A static route with the newly created tunnel allows any traffic hitting the BIG-IP system and destined for the specified subnet to be routed through the tunnel.

Watch how to add a static route for web traffic

  1. On the Main tab, click Network > Routes.
    The Routes screen opens.
  2. Click Add.
    The New Route screen opens.
  3. Configure the settings described in this table. For all other settings, use the defaults.
    Setting Details
    Name Type a unique name for the static route, such as my_static_route.
    Destination Type a destination IP address for the route. For example, 172.16.101.0.
    Netmask Type the netmask for the destination IP address. For example, 255.255.255.0.
    Resource Select Use VLAN/Tunnel.
    VLAN/Tunnel Select the VLAN associated for the specified self IP address, such as my_tunnel.
  4. Click Finished.
    The screen refreshes and displays the new static route in the list.

Disable load balancing and forward web traffic through the tunnel

Use these steps to create a forwarding virtual server to move traffic to the destination address.

Selecting Forwarding (IP) for Type specifies a virtual server like other virtual servers, except that the virtual server has no pool members to load balance. The virtual server forwards the packet directly to the destination IP address specified in the client request.

Watch how to forward web traffic through the tunnel

  1. On the Main tab, click Local Traffic > Virtual Servers.
    The Virtual Server List screen opens.
  2. Click the Create button.
    The New Virtual Server screen opens.
  3. Configure the settings described in this table. For all other settings, use the defaults.
    Section Setting Details
    General Properties Name Type a unique name for the virtual server, such as my_forwarding_vs.
    General Properties Type Select Forwarding (IP).
    General Properties Source Address Type an IP address from which the virtual server accepts traffic. For example, 0.0.0.0/0.
    General Properties Destination Address/Mask Type an IP address to which the virtual server sends traffic. For example, 0.0.0.0/0.
    General Properties Service Port Type a service port number and select * All Ports. For example, 0.
    Configuration Protocol Select All Protocols.
  4. Click Finished.
    The screen refreshes and displays the virtual server in the list.
  5. Select the check box for the virtual server and click Enable.

Other resources

For information about IKE or related industry-standard technologies, see the relevant IETF RFCs (Request for Comments).

For information about the F5 BIG-IP platform and Microsoft Azure, see The BIG-IP® Platform and Microsoft Azure: Application Services in the Cloud whitepaper at https://f5.com.

For information about the F5 BIG-IP Virtual Edition and Azure, see BIG-IP® Virtual Edition and Microsoft Azure: Setup on the AskF5™ Knowledge Base at http://support.f5.com.

For information about Azure VPN Gateway documentation, see Create a VNet with a Site-to-Site connection using PowerShell at https://azure.microsoft.com/en-us/documentation/articles/vpn-gateway-create-site-to-site-rm-powershell/.

For videos that walk you through common business tasks, see: https://www.youtube.com/playlist?list=PLyqga7AXMtPPi-MPCs8eC2b3EZDNqHuBO

Or, search for F5: Make It Work! on our DevCentral YouTube channel.