Set Up an IKE Gateway

To set up a VPN tunnel, the VPN peers or gateways must authenticate each other—using pre-shared keys or digital certificates—and establish a secure channel in which to negotiate the IPSec security association (SA) that will be used to secure traffic between the hosts on each side.
  1. Define the IKE Gateway.
    1. Select NetworkNetwork ProfilesIKE Gateways, Add a gateway, and enter the gateway Name (General tab).
    2. Set the Version to IKEv1 only mode, IKEv2 only mode, or IKEv2 preferred mode. The IKE gateway begins its negotiation with its peer in the mode you specify here. If you select IKEv2 preferred mode, the two peers will use IKEv2 if the remote peer supports it; otherwise they will use IKEv1.
      The Version you select also determines which options are available for you to configure on the Advanced Options tab.
  2. Establish the local endpoint of the tunnel (gateway).
    1. Select the Address Type: IPv4 or IPv6.
    2. Select the physical, outgoing Interface on the firewall where the local gateway resides.
    3. From the Local IP Address drop-down, select the IP address that the VPN connection will use as the endpoint; this is the external-facing interface with a publicly routable IP address on the firewall.
  3. Establish the peer at the far end of the tunnel (gateway).
    For Peer IP Address Type, select one of the following and enter the corresponding information for the peer:
    • IP—Enter a Peer Address that is either an IPv4 or IPv6 address or enter an address object that is an IPv4 or IPv6 address.
    • FQDN—Enter a Peer Address that is an FQDN string or an address object that uses an FQDN string. If the FQDN or FQDN address object resolves to more than one IP address, the firewall selects the preferred address from the set of addresses that match the Address Type (IPv4 or IPv6) of the IKE gateway as follows:
      • If no IKE security association (SA) is negotiated, the preferred address is the IP address with the smallest value.
      • If the IKE gateway uses an address that is in the set of returned addresses, the firewall selects that address (whether or not it is the smallest address in the set).
      • If the IKE gateway uses an address that isn’t in the set of returned addresses, the firewall selects a new address, and it is the smallest address in the set.
    • Dynamic—Select Dynamic if the peer IP address or FQDN value is unknown so that the peer will initiate the negotiation.
      Using an FQDN or FQDN address object reduces issues in environments where the peer is subject to dynamic IP address changes (and would otherwise require you to reconfigure this IKE gateway peer address).
  4. Specify how to authenticate the peer.
    Select the Authentication method: Pre-Shared Key or Certificate. If you choose a pre-shared key, proceed to the next step. If you choose a certificate, skip ahead to Configure certificate-based authentication.
  5. Configure a pre-shared key.
    1. Enter a Pre-shared Key, which is the security key for authentication across the tunnel. Re-enter the value to Confirm Pre-shared Key. Use a maximum of 255 ASCII or non-ASCII characters.
      Generate a key that is difficult to crack with dictionary attacks; use a pre-shared key generator, if necessary.
    2. For Local Identification, choose from the following types and enter a value that you determine: FQDN (hostname), IP address, KEYID (binary format ID string in HEX), and User FQDN (email address). Local identification defines the format and identification of the local gateway. If you do not specify a value, the local IP address is used as the local identification value.
    3. For Peer Identification, choose from the following types and enter a value that you determine: FQDN (hostname), IP address, KEYID (binary format ID string in HEX), and User FQDN (email address). Peer identification defines the format and identification of the peer gateway. If you do not specify a value, the peer IP address is used as the peer identification value.
    4. Proceed to Step 7 and continue from there.
  6. Configure certificate-based authentication.
    Perform the remaining steps in this procedure if you selected Certificate as the method of authenticating the peer gateway at the opposite end of the tunnel.
    1. Select a Local Certificate—one that is already on the firewall—from the drop-down, Import a certificate, or Generate a new certificate.
    2. (Optional) Enable (select) theHTTP Certificate Exchange to configure Hash and URL (IKEv2 only). For an HTTP certificate exchange, enter the Certificate URL. For more information, see Hash and URL Certificate Exchange.
    3. Select the Local Identification type—Distinguished Name (Subject), FQDN (hostname), IP address, or User FQDN (email address)—and then enter the value. Local identification defines the format and identification of the local gateway.
    4. Select the Peer Identification type—Distinguished Name (Subject), FQDN (hostname), IP address, or User FQDN (email address)—and then enter the value. Peer identification defines the format and identification of the peer gateway.
    5. Specify the type of Peer ID Check:
      • Exact—Ensures that the local setting and peer IKE ID payload match exactly.
      • Wildcard—Allows the peer identification to match as long as every character before the wildcard (*) matches. The characters after the wildcard need not match.
    6. (Optional) Permit peer identification and certificate payload identification mismatch to allow a successful IKE SA even when the peer identification does not match the peer identification in the certificate.
    7. Choose a Certificate Profile from the drop-down. A certificate profile contains information about how to authenticate the peer gateway.
    8. (Optional) Enable strict validation of peer’s extended key use to strictly control how the key can be used.
  7. Configure advanced options for the gateway.
    1. (Optional) Enable Passive Mode in the Common Options (Advanced Options) to specify that the firewall only respond to IKE connection requests and never initiate them.
    2. If you have a device performing NAT between the gateways, Enable NAT Traversal to use UDP encapsulation on IKE and UDP protocols, which enables them to pass through intermediate NAT devices.
    3. If you configured IKEv1 only mode in step 1, then, on the IKEv1 tab:
      • Select the Exchange Mode: auto, aggressive, or main. When set a firewall to use auto exchange mode, it can accept both main mode and aggressive mode negotiation requests; however, when possible, it will initiate exchanges in main mode.
        If you do not set the exchange mode to auto, then you must configure both peers with the same exchange mode to allow each peer to accept negotiation requests.
      • Select an existing profile or keep the default profile from the IKE Crypto Profile drop-down. If needed, you can Define IKE Crypto Profiles.
      • (Only when using certificate-based authentication and when exchange mode is not set to aggressive mode) Click Enable Fragmentation to enable the firewall to operate with IKE Fragmentation.
      • Click Dead Peer Detection and enter an Interval (range is 2 to 100 seconds). For Retry, define the time to delay (range is 2 to 100 seconds) before attempting to re-check availability. Dead peer detection identifies inactive or unavailable IKE peers by sending an IKE phase 1 notification payload to the peer and waiting for an acknowledgment.
    4. If you configured IKEv2 only mode or IKEv2 preferred mode in step 1, then on the IKEv2 tab:
      • Select an IKE Crypto Profile from the drop-down, which configures IKE Phase 1 options such, as the DH group, hash algorithm, and ESP authentication. For information about IKE crypto profiles, see IKE Phase 1.
      • (Optional) Enable Strict Cookie ValidationCookie Activation Threshold and Strict Cookie Validation.
      • (Optional) Enable Liveness Check and enter an Interval (sec) (default is 5) if you want to have the gateway send a message request to its gateway peer, requesting a response. If necessary, the Initiator attempts the liveness check as many as 10 times. If it doesn’t get a response, the Initiator closes and deletes the IKE_SA and CHILD_SA. The Initiator will start over by sending out another IKE_SA_INIT.
  8. Click OK and Commit your changes.

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