VPN Routing - Remote Access

In This Section: The Need for VPN Routing Check Point Solution for Greater Connectivity and Security Configuring VPN Routing for Remote Access VPN Link Selection for Remote Clients Directional VPN in Remote Access Communities

The Need for VPN Routing

There are a number of scenarios in which a Security Gateway or remote access clients cannot connect directly to another Security Gateway (or clients). Sometimes, a given Security Gateway or client is incapable of supplying the required level of security. For example:

• Two Security Gateways with dynamically assigned IP addresses (DAIP Security Gateways). Hosts behind either Security Gateway need to communicate; however, the changing nature of the IP addresses means the two DAIP Security Gateways cannot open VPN tunnels. At the moment of tunnel creation, the exact IP address of the other is unknown.
• Remote access client users wish to have a private conversation using Voice-over-IP (VoIP) software or utilize other client-to-client communication software such as Microsoft NetMeeting. Remote access clients cannot open connections directly with each other, only with configured Security Gateways.

In all cases, a method is needed to enhance connectivity and security.

Check Point Solution for Greater Connectivity and Security

VPN routing provides a way of controlling how VPN traffic is directed. VPN routing can be implemented with Security Gateway modules and remote access clients. Configuration for VPN routing is performed either directly through SmartConsole (in simple cases) or by editing the VPN routing configuration files on the Security Gateways (in more complex scenarios).

Item	Description
1	Host machines
2	Security Gateway A
3	Internet
4	Security Gateway B
5	Host machines
6	Security Management Server
7	Security Gateway C
8	Host machines

In the figure above, one of the host machines behind Security Gateway A needs to connect with a host machine behind Security Gateway B. For either technical or policy reasons, Security Gateway A cannot open a VPN tunnel with Security Gateway B. However, both Security Gateways A and B can open VPN tunnels with Security Gateway C, so the connection is routed through Security Gateway C.

As well as providing enhanced connectivity and security, VPN routing can ease network management by hiding a complex network of Security Gateways behind a single Hub.

Hub Mode (VPN Routing for Remote Clients)

VPN routing for remote access clients is enabled via Hub Mode. In Hub mode, all traffic is directed through a central Hub. The central Hub acts as a kind of router for the remote client. Once traffic from remote access clients is directed through a Hub, connectivity with other clients is possible as well as the ability to inspect the subsequent traffic for content.

When using Hub mode, enable Office mode. If the remote client is using an IP address supplied by an ISP, this address might not be fully routable. When Office mode is used, rules can be created that relate directly to Office mode connections.

Note - Office mode is not supported in SecuRemote.

Allowing Clients to Route all Traffic Through a Security Gateway

In the following figure, the remote client needs to connect with a server behind Security Gateway 2. Company policy states that all connections to this server must be inspected for content. For whatever reason, Security Gateway 2 cannot perform the required content inspection. When all the traffic is routed through Security Gateway 1, connections between the remote client and the server can be inspected.

Item	Description
1	Security Gateway 1
2	Internet
3	Remote client
4	Security Gateway 2
5	Server
6	Hosts

Suppose the same remote client needs to access an HTTP server on the Internet. The same company policy regarding security still applies.

Item	Description
1	HTTP Server
2	Internet
3	Remote client
4	Security Gateway
5	OSPEC Certified UFP server
6	Hosts

The remote client's traffic is directed to the Security Gateway where it is directed to the UFP (URL Filtering Protocol) server to check the validity of the URL and packet content, since the Security Gateway does not possess URL-checking functionality. The packets are then forwarded to the HTTP server on the Internet.

NATing the address of the remote client behind the Security Gateway prevents the HTTP server on the Internet from replying directly to the client. If the remote client's address is not NATed, the remote client will not accept the clear reply from the HTTP server.

Remote Client to Client Communication

Remote client to client connectivity is achieved in two ways:

• By routing all the traffic through the Security Gateway
• Including the Office Mode range of addresses in the VPN domain of the Security Gateway

Routing all Traffic through the Security Gateway

Two remote users use VoIP software to hold a secure conversation. The traffic between them is directed through a central Hub, as shown in the following figure.

Item	Description
1	Security Gateway
2	Internet
3	Remote Client VoIP
4	Remote Client VoIP

For this to work:

• Allow VPN clients to route traffic through this gateway must be enabled on the Security Gateway.
• The remote client must be configured with a profile that enables all traffic to be routed through the Security Gateway.
• Remote clients are working in connect mode.

If the two remote clients are configured for Hub mode with different Security Gateways, the routing takes place in three stages - each remote client to its designated Security Gateway, then between the Security Gateways:

Item	Description
1	Remote Client 1
2	Remote Client 2
3	Internet
4	Security Gateway A
5	Security Gateway B

In the figure above, remote client 1 is configured for Hub mode with Security Gateway B. Remote client 2 is configured for Hub mode with Security Gateway A. For the connection to be routed correctly:

• Office mode must be enabled.
• VPN configuration files on both Security Gateways must include the Office Mode address range used by the other. The VPN configuration file on Security Gateway A directs all traffic aimed at an Office Mode IP address of Security Gateway B towards Security Gateway B. A connection leaves Remote Client1 and is sent to Security Gateway B. From gateway B the connection is passed to Security Gateway A. Security Gateway A once more redirects the traffic towards Remote Client 2. The reply from Remote Client2 follows the same path but in reverse.
• Office mode addresses used by both Security Gateways must be non-overlapping.

Configuring VPN Routing for Remote Access VPN

Common VPN routing scenarios can be configured through a VPN star community, but not all VPN routing configuration is handled through SmartConsole. VPN routing between Security Gateways (star or mesh) can be also be configured by editing the configuration file $FWDIR/conf/vpn_route.conf

VPN routing cannot be configured between Security Gateways that do not belong to a VPN community.

Hub Mode for Remote Access Clients

To enable Hub Mode for Remote Access clients:

1. Click Gateways & Servers and double-click the Security Gateway.

   The gateway window opens and shows the General Properties page.

2. From the navigation tree, click VPN Clients > Remote Access.
3. In the Hub Mode configuration section, click Allow VPN clients to route all traffic through this gateway.
4. Click OK.
5. From the Objects Bar, click VPN Communities.
6. Double-click the Remote Access community object.
7. From the Participating Gateways page, make sure that the Hub Security Gateway is in the window.
8. On the Participant User Groups page, select the remote access users or user groups.
9. Click OK.
10. Create the access control rule in the Access Control Policy.

    VPN routing traffic is handled in the Security Policy Rule Base as a single connection, matched to one rule only.

11. Click OK and publish the changes.
12. Configure the profile on the remote client to route all communication through the designated Security Gateway.

Adding the Office Mode Range to the VPN Domain

SmartConsole includes a default object for Office Mode IP addresses, CP_default_Office_Mode_addresses_pool. You can use the default object, or create a new one for your network.

To create a new Office Mode IP address object:

1. In SmartConsole, click Objects > Object Explorer (Ctrl+E).
2. Click New > Network.
3. Enter the Name, IP address and Net mask.
4. Click OK and publish the changes.

To configure VPN routing for remote access clients with the VPN domain:

1. Create a network group, click New > Network Group.
2. Add these network groups:
   • VPN domain
   • Office Mode
3. Click OK and publish the changes.
4. Click Gateways & Servers and double-click the Security Gateway.

   The gateway window opens and shows the General Properties page.

5. From the navigation tree, click Network Management > VPN Domain.
6. Click Manually defined.
7. Select the new network group.
8. Click OK and publish the changes.

   The remote clients must connect to the site and perform a site update before they can communicate with each other.

Client to Client via Multiple Hubs Using Hub Mode

The figure below shows two remote clients each configured to work in Hub mode with a different Security Gateway:

Item	Description
1	Hub 1
2	Internet
3	Remote Client 1
4	Remote Client 2
5	Hub 2

Remote Client 1 works in Hub mode with Hub 1. Remote Client 2 works in Hub mode with the Hub 2. In order for VPN routing to be performed correctly:

• Remote clients must be working in Office mode
• Office mode address range of each Security Gateway must be included in the vpn_route.conf file installed on the other Security Gateway.

  Destination	Next hop router interface	Install On
  Hub1_OfficeMode_range	Hub1	Hub2
  Hub2_OfficeMode_range	Hub2	Hub1

When Remote Client 1 communicates with Remote Client 2:

• The traffic first goes to the Hub 1, since Remote Client 1 is working in Hub mode with Hub 1.
• Hub 1 identifies Remote Client 2's IP address as belonging to the Office mode range of Hub 2.
• The vpn_route.conf file on Hub 1 identifies the next hop for this traffic as Hub 2.
• The traffic reaches the Hub 2; Hub 2 redirects the communication to Remote Client 2.

Link Selection for Remote Clients

Link Selection is a method used to determine which interface to use for incoming and outgoing VPN traffic and the best possible path for the traffic. Using Link Selection, you choose which IP addresses are used for VPN traffic on each Security Gateway.

Load Sharing and Service Based Link Selection are not supported when the peer is a Remote Access Client. If the Probing Redundancy mode configuration is Load Sharing and the peer is a remote access client, High Availability will be enforced for the client's tunnel.

Link selection is configured on each Security Gateway in the Security Gateway Properties > IPSec VPN > Link Selection window. The settings apply to both:

• Security Gateway to Security Gateway connections
• Remote access client to Security Gateway connections

You can configure Link Selection for remote users separately. These settings override the settings configured on the Link Selection page.

Configuring Link Selection for Remote Access Only

To configure separate Link Selection settings for remote access VPN:

1. Connect with GuiDBedit Tool (see sk13009) to Security Management Server.
2. In the top left pane, to Network Objects > network_objects.
3. In the top right pane, select the Security Gateway / cluster object.
4. In the bottom pane, change the value of apply_resolving_mechanism_to_SR to false.
5. In the bottom pane, edit the ip_resolution_mechanism attribute to determine how remote access clients resolve the IP address of the local Security Gateway. Add one of the following:
   • mainIpVpn - Always use the main IP address specified in the IP Address field on the General Properties page of the Security Gateway
   • singleIpVpn - The VPN tunnel is created with the Security Gateway using an IP address set in single_VPN_IP_RA
   • singleNATIpVPN - The VPN tunnel is created using a NATed IP address set in single_VPN_IP_RA
   • topologyCalc - Calculate the IP address used for the VPN tunnel by network topology based on the location of the remote peer
   • oneTimeProb - Use one time probing to determine which link will be used.
   • ongoingProb - Use ongoing probing to determine which link will be used.
6. In the bottom pane, edit these parameters if you are using ongoing or one time probing:
   • interface_resolving_ha_primary_if – The primary IP address used for one-time / ongoing probing.
   • use_interface_IP – Set to true if all IP addresses defined in topology tab should be probed. Set to false if the manual list of IP addresses should be probed.
   • available_VPN_IP_list - A List of IP addresses that should be probed. (This list is used only if the value of use_interface_IP is false).
7. Save changes (File menu > Save All).
8. Close the GuiDBedit Tool.
9. In SmartConsole, install the Access Policy on the Security Gateway / cluster object.

To use multiple external links with remote access clients:

1. Open SmartConsole.
2. Double-click the Security Gateway / cluster object.

   The gateway window opens and shows the General Properties page.

3. From the navigation tree, click VPN Clients > Office Mode.
4. In the Multiple Interfaces section, select Support connectivity enhancement for gateways with multiple external interfaces.
5. Click OK.
6. Install policy on the gateway / cluster object.

Directional VPN in Remote Access Communities

Directional VPN for Remote Access Communities lets you reject connections to or from a specified network object.

Source	Destination	VPN	Service	Action
Any	Any	Remote_Access_Community => MyIntranet	Any	drop
Any	Any	Remote_Access_Community => Any Traffic	Any	accept

Connections are not allowed between remote users and hosts within the "MyIntranet" VPN community. All other connections that start from the Remote Access Community, from inside or outside of the VPN communities, are allowed.

User Groups as the Destination in RA communities

User groups can be placed in the destination column of a rule. This makes:

• Configuring client to client connections easier
• Configuring "back connections" between a remote client and a Security Gateway possible.

  Source	Destination	VPN	Service	Action
  Any	Remote_Users@Any	Any Traffic => Remote_Access_Community	Any	accept

To include user groups in the destination column of a rule:

• The rule must be directional
• In the VPN column, the Remote Access community must be configured as the endpoint destination

Configuring Directional VPN with Remote Access Communities

To configure Directional VPN with Remote Access communities:

1. From Menu, click Global Properties.
2. From the navigation tree, click VPN > Advanced.
3. Click Enable VPN Directional Match in VPN Column.
4. Click OK and publish the changes.
5. Go to Security Policies > Access Control Policy.
6. Right-click the VPN cell for the rule, and select Directional Match Condition.

   The New Directional Match Condition window opens.

7. Configure the directional VPN:
   • From Traffic reaching from, select the source of the connection
   • From Traffic leaving to, select the connection's destination
8. Click OK.
9. Install policy.