Configure IPsec NAT-T

About this task

By default, both sides of an IPsec connection are Initiator devices. IPsec Network Address Translation Traversal (NAT-T) connections require that one side of the connection is a Responder device and the other side of the connection is an Initiator device.

If the Responder device and the Initiator device are both behind NAT, the IPsec NAT-T Initiator device requires the public IP address of the Responder device.

Procedure

Perform the following steps to configure one side of an IPsec NAT-T connection as a Responder device:

In the navigation pane, expand Configuration > IS-IS.
Select IS-IS.
Select Logical Interfaces.
Select Insert.
Select IpsecNatConfigResponderOnly.

If required, perform the following steps on the IPsec NAT-T Initiator device to configure the public IP address of the Responder device:

In the navigation pane, expand Configuration > IS-IS.
Select IS-IS.
Select Logical Interfaces.
Select Insert.
For IpsecNatConfigRemoteNatIPAddr, enter the public IP address of the Responder device.

Logical Interfaces Field Descriptions

Use the data in the following table to use the Logical Interfaces tab and the Insert Logical Interfaces dialog. The available fields in the dialog differ depending on the type of core you select: layer 2 or ip.


Name	Description
Id	Specifies the index number that uniquely identifies this logical interface. This field displays on the Insert Logical Interfaces dialog only.
IfIndex	Specifies the index number that uniquely identifies this logical interface. This field is read-only. This field displays on the Logical Interfaces tab only.
Name	Specifies the administratively assigned name of this logical interface, which can be up to 64 characters.
Type Note: Exception: Type Layer 2 is not supported on XA1400 Series.	Specifies the type of logical interface to create: Specify layer 2 for a Layer 2 core network that the tunnel will traverse. Specify ip for a Layer 3 core network that the tunnel will traverse.
DestIPAddr	Specifies the destination IP address for the IP-type logical interface.
DestIfIndex Note: Exception: Not supported on XA1400 Series.	Specifies the physical port or MultiLink Trunking (MLT) that the Layer 2 logical interface is connected to.
Vids Note: Exception: Not supported on XA1400 Series.	Specifies the list of VLANs that are associated with this logical interface.
PrimaryVid Note: Exception: Not supported on XA1400 Series.	Specifies the primary tunnel VLAN ID associated with this L2 Intermediate-System-to-Intermediate-System (IS-IS) logical interface.
CircIndex Note: Exception: Not supported on XA1400 Series.	Identifies the IS-IS circuit created under the logical interface. This field displays on the Logical Interfaces tab only.
NextHopVrf Note: Exception: Not supported on XA1400 Series.	Identifies the next-hop VRF name to reach the logical tunnel destination IP. This field displays on the Logical Interfaces tab only.
IpsecEnable Note: Exception: Only supported on XA1400 Series.	Specifies whether the logical interace should use IPsec.
AuthenticationKey Note: Exception: Only supported on XA1400 Series.	Specifies the authentication key of this logical interface, which can be up to 32 characters.
ShapingRate Note: Exception: Only supported on XA1400 Series.	Specifies the value, in Mbps, of the Egress Tunnel Shaper applied to the logical interface.
Mtu	Specifies the Maximum Transmission Unit (MTU) size for each logical interface. The default MTU value is 1950.
EncryptionKeyLength Note: Exception: Only supported on XA1400 Series.	Specifies the IPsec encryption key length for FE tunnel, which can be 128 bit or 256 bit. The default value is len128bit.
IpsecTunnelDestAddress Note: Exception: Only supported on XA1400 Series.	Specifies the destination IP address for the IPsec tunnel.
BfdEnable Note: Exception: Not supported on VSP 8600 Series or VSP 4450 Series.	Enables or disables BFD on an IS-IS Logical Interface.
IpsecResponderOnly Note: Exception: Only supported on XA1400 Series.	Specifies whether the device is a Responder device in an IPsec Network Address Translation Traversal (NAT-T) connection.
IpsecRemoteNatIPAddr Note: Exception: Only supported on XA1400 Series.	Specifies the public IP address of the NAT router connected to the Responder device in an IPsec NAT-T connection.
IpsecAuthMethod Note: Exception: Only supported on XA1400 Series.	Configures the IPsec authentication method for the tunnel as either a pre-shared key or RSA signature for digital certificates. The default is pre-shared key.
IpsecCompression Note: Exception: Only supported on XA1400 Series.	Reduces the size of the IP datagram to improve the communication performance between hosts connected behind Backbone Edge Bridges (BEB). Tip: As a best practice, use IPsec compression only for Fabric Extend tunnels where latency is greater than 70ms.