VPN example: Remote Access VPN, Router(Routing-based VPN), Windows 7/8/10(client), One-armed, Behind a NAT/NAPT and certificate for both Windows 7/8/10 and Rockhoppper (PKCS#12/X.509).


The following image shows example network for this scenario.

Ubuntu is installed on VPN Gateway(Router/Remote Access Server), Internal host/Internal DNS server, Router1(Source NAPT) and Router2(Destination NAPT or Port Forwarding).

Rockhopper VPN software is installed on VPN Gateway. A VPN is connected between this node and Windows 7/8/10 VPN Client(IKEv2). VPN Gateway works as a router between VPN (internal subnet, 192.168.100.0/24) for Windows 7/8/10 VPN Client and protected network (LAN, 192.168.0.0/24). The gateway is deployed as a one-armed gateway.

RSA-Signature(certificate) is used for both Windows 7/8/10 VPN Client and VPN Gateway.

Windows 7/8/10 VPN Client and VPN Gateway are located behind a NAT(NAPT). Router1 and Router2 provide NAT/NAPT(Network Address Port Translation) service or Port Forwarding service for them.



sample0

rhpvif10 on VPN Gateway: A virtual interface(a Tunnel/TAP interface) to access internal network. "10" is the VPN realm ID. This interface is automatically created by Rockhopper VPN service and configured not by system tools like ifconfig command but by Rockhopper Web console.

eth0 and/or eth1 on each host: Real interfaces to access physical network.


A VPN realm is a security domain for group members to share the same security policy and VPN configuration. For instance, you can define the VPN realm "10" for a sales team and the other VPN realm "20" for a developing team.


Advance preparation:


- VPN Gateway(gateway1.example.com):
# sudo ifconfig eth0 192.168.0.100 netmask 255.255.255.0

Add a default route to the internet.
# sudo route add default gw 192.168.0.10

Add a route to the other internal subnet(192.168.1.0/24).
# sudo route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.0.1

Enable IPv4 routing.
# sudo sysctl net.ipv4.ip_forward=1


- Router1(Port Forwarding):
# sudo ifconfig eth0 10.0.0.1 netmask 255.255.255.0
# sudo ifconfig eth1 192.168.0.10 netmask 255.255.255.0

Enable IPv4 routing.
# sudo sysctl net.ipv4.ip_forward=1

Forward packets destinated to 10.0.0.1:500(Router1) to 192.168.0.100:500(VPN Gateway).
# sudo iptables -t nat -A PREROUTING -p udp --dst 10.0.0.1 --dport 500 -j DNAT --to-destination 192.168.0.100:500

Forward packets destinated to 10.0.0.1:4500(Router1) to 192.168.0.100:4500(VPN Gateway).
# sudo iptables -t nat -A PREROUTING -p udp --dst 10.0.0.1 --dport 4500 -j DNAT --to-destination 192.168.0.100:4500

Add a route to the VPN's subnet(192.168.100.0/24).
# sudo route add -net 192.168.100.0 netmask 255.255.255.0 gw 192.168.0.100

- Router2(Source NAPT):
# sudo ifconfig eth0 10.0.0.10 netmask 255.255.255.0
# sudo ifconfig eth1 192.168.2.1 netmask 255.255.255.0

Enable IPv4 routing.
# sudo sysctl net.ipv4.ip_forward=1

Exec NAPT for packets from private network(192.168.2.0/24).
# sudo iptables -t -nat -A POSTROUTING -o eth0 -j MASQUERADE --random

- Internal host/Internal DNS server:
# sudo ifconfig eth0 192.168.0.101 netmask 255.255.255.0

Add a route to the VPN's subnet(192.168.100.0/24) for DNS queries from Windows 7/8/10 VPN Client.
# sudo route add -net 192.168.100.0 netmask 255.255.255.0 gw 192.168.0.100

Above configuration will be lost after you restart your computer. To setup permanent configuration, you can edit /etc/network/interface and /etc/sysctl.conf. The followings are an example for VPN Gateway(gateway1.example.com) on Ubuntu.

- /etc/network/interface (Ubuntu):
auto eth0
iface eth0 inet static
address 192.168.0.100
network 192.168.0.0
netmask 255.255.255.0
gateway 192.168.0.10
up route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.0.1

- /etc/sysctl.conf (Ubuntu):

# Uncomment the next line to enable packet forwarding for IPv4
net.ipv4.ip_forward=1


- PKCS#12 files:

   - VPN Gateway(Router): gateway1.example.com.p12 (PKCS#12)
   - Windows 7/8/10 VPN Client: remotehost1.example.com.p12 (PKCS#12)

   The certificate(X.509) for each node includes a subjectAltName(Host name/FQDN).
   - VPN Gateway: gateway1.example.com (Host name/FQDN)
   - Windows 7/8/10 VPN Client: remotehost1.example.com (Host name/FQDN)

See "Tips: Creating a Rockhopper's certificate compatible with a Windows 7/8/10 VPN client by XCA." and "Documents/Tips: Managing certificates by XCA" to create each PKCS#12 file, including a private key and a certificate(X.509) for VPN Gateway or Windows 7/8/10 VPN Client and a CA certificate(X.509).


Configuring VPN:


VPN Gateway(gateway1.example.com):


  1. Open Rockhopper Web console on http://127.0.0.1:32501 (by default) by Firefox.
  2. Login with administrator's name and password. (by default, admin and secret).
  3. If VPN Configuration tab is not shown, uncheck Hide configuration tabs checkbox.
  4. Add a new VPN realm.

    - VPN Configuration[Tab] > Edit VPN Realm(Save, Add, etc.)[Left-Tree]:
    Click this tree node and show Edit VPN Realm(Save, Add, Remove, or Load) pane.

    - Click Add VPN Realm button.

    - Add a VPN Realm[Dialog]: Enter the following, then click OK button.

    Realm ID: 10
    Realm Name: Example VPN
    Description: Config for Example VPN.
    Mode: Router


  5. Setup VPN Interface.

    - VPN Configuration[Tab] > VPN Realms[Left-Tree] > 10:Example VPN(Bridge)[Left-Tree] > VPN Interface[Left-Tree]:
    Click this tree node and show VPN Tunnel/TAP Interface pane.

    - Enter or select the following.

    Internal Address Type: Static Address
    Internal IPv4 Address: 192.168.100.1
    Netmask: 255.255.255.0


  6. Setup Network Interface.

    - VPN Configuration[Tab] > VPN Realms[Left-Tree] > 10:Example VPN(Bridge)[Left-Tree] > Network Interface[Left-Tree]:
    Click this tree node and show Network Interface pane.

    - Select eth0 to establish VPN.


  7. Setup Service.

    - VPN Configuration[Tab] > VPN Realms[Left-Tree] > 10:Example VPN(Bridge)[Left-Tree] > Service[Left-Tree]:
    Click this tree node and show Service pane.

    - Network Deployment: Select Hub(Concentrator) Node.

    - Remote Configuration(IKEv2): Select Remote Configuration Server.


  8. Setup Remote Config Server.

    - VPN Configuration[Tab] > VPN Realms[Left-Tree] > 10:Example VPN(Bridge)[Left-Tree] >Service[Left-Tree] > Remote Config Server[Left-Tree]:
    Click this tree node and show Remote Config Server(IKEv2) pane.


  9. Setup Remote Config Server - Internal Address Pool.

    - Remote Config Server(IKEv2)[Pane] > Internal Address Pool[Tab]:
    Click Add Address Pool button.

    - Add a New Address Pool[Dialog]: Enter the following, then click OK button.
    Address Type: Address Range IPv4 Address Range: 192.168.100.20 - 192.168.100.30


  10. Setup Remote Config Server - Internal DNS.

    - Remote Config Server(IKEv2)[Pane] > Internal DNS[Tab]:
    Enter the following as an Internal DNS server's address.

    DNS Server's IPv4 Address: 192.168.0.101


  11. Setup My Key Store.

    - VPN Configuration[Tab] > VPN Realms[Left-Tree] > 10:Example VPN(Bridge)[Left-Tree] > My Key Store[Left-Tree]:
    Click this tree node and show My Key Store pane.

    - Enter the following.

    Authentication Method: RSA Signature(RSA-Sig)
    My ID Type: auto
    Imported Key Format: PKCS#12 - File
    PKCS#12 file(*.p12): gateway1.example.com.p12
    RSA Private Key's Password: himitsu


  12. Finally, save this realm's configuration.

    - VPN Configuration[Tab] > Edit VPN Realm(Save, Add, etc.)[Left-Tree]: Click this tree node and show "Edit VPN Realm(Save, Add, Remove, or Load)" pane.

    - Click Save Configuration button.



Windows 7 VPN Client:


- Import a certificate, a private key and a CA certificate for the Computer account by Microsoft Management Console(MMC).


  1. Open Microsoft Management Console(MMC) by clicking the Start button, enter "mmc" into the search box, and push Enter.
  2. On the File menu, point to Add/Remove Snap-in, and open the Add or Remove Snap-ins dialog.
  3. Click the certificates under Available snap-ins and push Add.
  4. Select the Computer account and push Next.
  5. Select the Local computer and push Finish.
  6. Push OK on Add or Remove Snap-ins dialog and close it.
  7. Click the folder Certificates(Local Computer) / Personal / Certificates folder, click the Action menu, point to All Tasks, and then click Import.
  8. Click Next and follow the instructions.
    - An imported PKCS#12 file: remotehost1.example.com.p12
    - Password for the private key: naisho
  9. If a CA's certificate (TestCA) is extracted into Certificates(Local Computer) / Personal / Certificates folder, move it to Certificates(Local Computer) / Trusted Root Certification Authorities / Certificates folder by dragging and dropping the certificate's icon.

- Setup a VPN connection.


  1. Open Network and sharing center from Control Panel and select Set up a new connection or network.
  2. Click Connect to a workplace and push Next.
  3. Click Use my Internet connection (VPN).
  4. Enter gateway1.example.com into Internet Address and Example VPN into Destination name, check Don't connect now; just set it up so I can connect later and push Next.
  5. Enter "alice" into User Name and "1234567890" into Password. Push Create and close the wizard dialog. Actually, these information will not be used when you choose RSA-sinature(certificate) as an authentication method.
  6. Open Network and sharing center from Control Panel again and select Change adapter settings.
  7. Open the properties dialog of Example VPN adapter and show Security tab.
  8. Enter the following:
    - Type of VPN: IKEv2
    - Data encryption: Require encryption (disconnect if server declines)
    - Authentication: Use machine certificates
  9. Push OK.

- Edit the hosts file if DNS service is not available for gateway1.example.com.


  1. Open "C:Windows/System32/drivers/etc/hosts" by notepad as an administrator. If you can't find these folders, please see Show hidden files.
  2. Add the following line into this hosts file.

    10.0.0.1   gateway1.example.com   # (Example VPN)

  3. Save and close the file.

- Connect VPN


  1. Open Network and sharing center from Control Panel again and select Connect to a network.
  2. Connect Example VPN.


Windows 8 VPN Client:


Also, see Windows 8 VPN Get Connected by Microsoft.

- Import a certificate, a private key and a CA certificate for the Computer account by Microsoft Management Console(MMC).


  1. Move the cursor to the right corner of your screen and open Charms.
  2. Open Microsoft Management Console(MMC) by clicking the Search icon and entering "mmc" into the search box.
  3. On the File menu, point to Add/Remove Snap-in, and open the Add or Remove Snap-ins dialog.
  4. Click the certificates under Available snap-ins and push Add.
  5. Select the Computer account and push Next.
  6. Select the Local computer and push Finish.
  7. Push OK on Add or Remove Snap-ins dialog and close it.
  8. Click the folder Certificates(Local Computer) / Personal / Certificates folder, click the Action menu, point to All Tasks, and then click Import.
  9. Click Next and follow the instructions.
    - An imported PKCS#12 file: remotehost1.example.com.p12
    - Password for the private key: naisho
  10. If a CA's certificate (TestCA) is extracted into Certificates(Local Computer) / Personal / Certificates folder, move it to Certificates(Local Computer) / Trusted Root Certification Authorities / Certificates folder by dragging and dropping the certificate's icon.

- Setup a VPN connection.


  1. Move the cursor to the right corner of your screen and open Charms.
  2. Open Control Panel by clicking the Search icon and entering "Control Panel" into the search box.
  3. Open Network and sharing center from the Control Panel's Network and Internet and then click Set up a new connection or network.
  4. Click Connect to a workplace and push Next.
  5. Click Use my Internet connection (VPN).
  6. Enter gateway1.example.com into Internet Address and Example VPN into Destination name and push Create.
  7. Open Network and sharing center from Control Panel again and click Change adapter settings.
  8. Open the properties dialog of Example VPN adapter and show Security tab.
  9. Enter the following:
    - Type of VPN: IKEv2
    - Data encryption: Require encryption (disconnect if server declines)
    - Authentication: "Use machine certificates"
  10. Push OK.

- Edit the hosts file if DNS service is not available for gateway1.example.com as mentioned above.



- Connect VPN:


  1. Move the cursor to the right corner of your screen and open Charms.
  2. Click Settings and then click the Network icon.
  3. In Networks click the Example VPN connection and then push Connect.


Windows 10 VPN Client:


See Connect a Windows 10 VPN client with Rockhopper - Use machine certificate - PKCS#12/X.509.


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