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Check Point Security Gateway initiating an IKE negotiation over NAT-T Technical Level
  • Check Point Security Gateway does not propose using NAT-T during the IKE negotiation.

  • The $FWDIR/log/vpnd.elg file on the Security Gateway might contain this line:

    SwitchToNatT: Keep on using existing connection


In versions R77.30 and lower, Check Point Security Gateways did not support initiating IKE proposals over NAT-T.

A Security Gateway accepts and supports proposals for industry-standard UDP encapsulation over the UDP port 4500, but never initiates a proposal.

Note - The SMB Appliances 600, 1100, 1200R, and the VPN-1 Edge Devices do support initiating IKE propositions over NAT-T.



The NAT-T initiator capability was introduced in the R80.10 version.

You can control the Security Gateway behavior with the offer_nat_t_initator parameter in the Security Gateway object properties.

Parameter Value Security Gateway Behavior Notes
false Security Gateway does not initiate IKE proposals over NAT-T.

This is the default value in:

true Security Gateway initiates IKE proposals over NAT-T.

This is the default value in (see VPNS2S-2235):


To change the value of the parameter:

  1. Connect with SmartConsole to the Security Management Server / applicable Domain Management Server.

  2. In the top left corner, click Menu > Database Revision Control > create a revision snapshot.

    Note: Database Revision Control is not supported for VSX objects (sk65420) and Endpoint Security Servers.

    In addition, refer to:

  3. Close all SmartConsole windows.

    Verify by running the "cpstat mg" command on Security Management Server / in the context of each Domain Management Server.

  4. Connect with Database Tool (GuiDBedit Tool) to the Security Management Server / Domain Management Server.

  5. In the upper left pane, go to Table > Network Objects > network_objects.

  6. In the upper right pane, select the Security Gateway / Cluster object.

  7. Press CTRL+F (or go to Search menu > Find) > paste offer_nat_t_initator > click Find Next.

  8. In the lower pane, right-click on the offer_nat_t_initator > select Edit > select the applicable value > click OK.

  9. Save the changes: go to the File menu > click Save All.

  10. Close the Database Tool (GuiDBedit Tool).

  11. Connect with SmartConsole to the Security Management Server / Domain Management Server.

  12. Install the Security Policy onto the applicable Security Gateway / Cluster.


  • Check Point Security Gateways R80.10 in VSX mode do not support NAT-T initiation (see the VPN section in sk110519).

  • Check Point Security Gateways R80.10 support NAT-T initiation in IKEv2.

  • Check Point Security Gateways R77.30 and lower only support answering to NAT-T proposals from the VPN peer when all of these conditions are met:

    1. The peer gateway has a dynamically assigned IP address (DAIP).
    2. VPN community uses certificate-based authentication.
    3. The peer gateway initiates the NAT-T.

Related Solutions

This solution has been verified for the specific scenario, described by the combination of Product, Version and Symptoms. It may not work in other scenarios.

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