Setup IPsec Road-Warrior

Road Warriors are remote users who need secure access to the companies infrastructure. IPsec Mobile Clients offer a solution that is easy to setup with macOS (native) and is know to work with iOS as well as many Android devices.

For more flexibility use SSL VPNs, OPNsense utilizes OpenVPN for this purpose.

With this example we’ll show you how to configure the Mobile Client Setup in OPNsense and give you configuration examples for:

• macOS

• iOS

• Android

Note

For the sample we will use a private IP for our WAN connection. This requires us to disable the default block rule on wan to allow private traffic. To do so, go to the Interfaces ‣ [WAN] and uncheck “Block private networks”. (Dont forget to save and apply)

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Sample Setup

For the sample configuration we configure OPNsense

Company Network with Remote Client

Company Network

Hostname	fw1
WAN IP	172.18.0.164
LAN IP	192.168.1.0/24
LAN DHCP Range	192.168.1.100-192.168.1.200
IPsec Clients	10.10.0.0/24

Firewall Rules Mobile Users

To allow IPsec Tunnel Connections, the following should be allowed on WAN.

• Protocol ESP

• UDP Traffic on Port 500 (ISAKMP)

• UDP Traffic on Port 4500 (NAT-T)

To allow traffic passing to your LAN subnet you need to add a rule to the IPsec interface.

Step 1 - Mobile Clients

First we will need to setup the mobile clients network and authentication methods. Go to VPN ‣ IPsec ‣ Mobile Clients

For our example will use the following settings:

IKE Extensions

Enable	checked	check to enable mobile clients
User Authentication	Local Database	For the example we use the Local Database
Group Authentication	none	Leave on none
Virtual Address Pool	10.0.0.0/24	Enter the IP range for the remote clients

You can select other options, but we will leave them all unchecked for this example.

Save your settings and select Create Phase1 when it appears. Then enter the Mobile Client Phase 1 setting.

Step 2 - Phase 1 Mobile Clients

Phase 1 General information

Connection method	default	default is ‘Start on traffic’
Key Exchange version	V1	only V1 is supported for mobile clients
Internet Protocol	IPv4
Interface	WAN	choose the interface connected to the internet
Description	MobileIPsec	freely chosen description

Phase 1 proposal (Authentication)

Authentication method	Mutual PSK +Xauth	Using a Pre-shared Key and Login
Negotiation mode	Agressive	Select Aggressive
My identifier	My IP address	Simple identification for fixed ip
Peer identifier	User distinguished	Identification for peer
Pre-Shared Key	At4aDMOAOub2NwT6gMHA	Random key. CREATE YOUR OWN!

Phase 1 proposal (Algorithms)

Encryption algorithm	AES	For our sample we will Use AES/256 bits
Hash algoritm	SHA1	SHA1 for compatibility, you can try a stronger hash
DH key group	1024 bit	1024 bit for compatibility, you can try stronger group
Lifetime	28800 sec	lifetime before renegotiation

Advanced Options

Disable Rekey	Unchecked	Renegotiate when connection is about to expire
Disable Reauth	Unchecked	For IKEv2 only re-authenticate peer on rekeying
NAT Traversal	Enabled	Enable for IKEv1
Dead Peer Detection	Unchecked

Save your setting by pressing:

Now you should see the following screen:

Step 3 - Phase 2 Mobile Clients

Press the button that says ‘+ Show 0 Phase-2 entries’

You will see an empty list:

Now press the + at the right of this list to add a Phase 2 entry.

General information

Mode	Tunnel IPv4	Select Tunnel mode
Description	MobileIPsecP2	Freely chosen description

Local Network

Local Network

LAN subnet

Route the local LAN subnet

Phase 2 proposal (SA/Key Exchange)

Protocol	ESP	Choose ESP for encryption
Encryption algorithms	AES / 256	For the sample we use AES 256
Hash algorithms	SHA1	You may also try stronger SHA512
PFS Key group	off	Enable a group fro stronger security
Lifetime	3600 sec

Save your setting by pressing:

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Enable IPsec, Select:

Save:

And Apply changes:

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Note

If you already had IPsec enabled and added Road Warrior setup, it’s important to restart the whole service via services widget in the upper right corner of IPSec pages or via System ‣ Diagnostics ‣ Services ‣ Strongswan since applying configuration only reloads it, but a restart also loads the required modules of strongswan.

Step 4 - Add IPsec Users

For this example we will create a new user who may access the mobile IPsec vpn.

Go to System ‣ Access ‣ Users and press the + sign in the lower right corner to add a new user.

Enter the following into the form:

User Name	expert
Password	&test!9T

Save to apply.

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Step 5 - Configure Client

To illustrate the client setup we will look at the configuration under macOS, including some screenshots. The configurations for Android and iOS will be settings only.

Note

Configuration samples listed here where created using latest macOS, iOS and Android devices on time of publication in February 2016.

Configure macOS Client

Start with opening your network settings (System Preferences ‣ Network) and Add a new network by pressing the + in the lower left corner.

Now select VPN and Cisco IPSec, give your connection a name and press Create.

Now enter the details for our connection:

Next press Authentication Settings to add the group name and pre-shared key.

Press OK to save these settings and then Apply to apply them.

Now test the connection by selecting it from the list and hit Connect.

Done

Configure iOS Client

To add a VPN connection on an iOS device go to Settings ‣ General ‣ VPN. Select Add VPN Configuration chose IPsec and use the Following Settings:

Description	IPsec OPNsense	Freely chosen description
Server	172.18.0.164	Our server address
Account	expert	Username of the remote account
Password	&test!9T	Leave blank to be prompted every time
Preshared IPsec-key	At4aDMOAOub2NwT6gMHA	Our PSK

Configure Android Client

To add a VPN connection on an Android device go to Settings ‣ Connections ‣ more networks, select VPN. Press the + in the top right corner to add a new VPN connection.

Use the Following Settings:

Name	IPsec OPNsense	Freely chosen name
Type	IPSec Xauth PSK	As configured in OPNsense
Server address	172.18.0.164	Our server address
Preshared IPsec-key	At4aDMOAOub2NwT6gMHA	Our PSK

Save and try connecting. To connect enter Username and Password for the user expert we created in this example.