Configuring Cisco TrustSec Fibre Channel Link Encryption
This chapter provides an overview of the Cisco TrustSec Fibre Channel (FC) Link Encryption feature and describes how to configure and set up link-level encryption between switches.
This chapter includes the following topics:
Information About Cisco TrustSec FC Link Encryption
Cisco TrustSec FC Link Encryption is an extension of the Fibre Channel-Security Protocol (FC-SP) feature and uses the existing FC-SP architecture to provide integrity and confidentiality of transactions. Encryption is now added to the peer authentication capability to provide security and prevent unwanted traffic interception. Peer authentication is implemented according to the FC-SP standard using the Diffie-Hellman Challenge Handshake Authentication Protocol (DHCHAP) protocol.
 Note |
Cisco TrustSec FC Link Encryption is currently only supported between Cisco MDS switches. This feature is not supported when you downgrade to software versions which do not have the Encapsulating Security Protocol (ESP) support. |
This section includes the following topics:
Supported Modules
The following modules are supported for the Cisco TrustSec FC Link Encryption feature:
- 1/2/4/8 Gbps 24-Port Fibre Channel switching module (DS-X9224-96K9)
- 1/2/4/8 Gbps 48-Port Fibre Channel switching module (DS-X9248-96K9)
- 1/2/4/8 Gbps 4/44-Port Fibre Channel switching module (DS-X9248-48K9)
Cisco TrustSec FC Link Encryption Terminology
The following Cisco TrustSec FC Link Encryption-related terms are used in this chapter:
- Galois Counter Mode (GCM)—A block cipher mode of operation providing confidentiality and data-origin authentication.
- Galois Message Authentication Code (GMAC)—A block cipher mode of operation providing only data-origin authentication. It is the authentication-only variant of GCM.
- Security Association (SA)—A connection that handles the security credentials and controls how they propagate between switches. The SA includes parameters such as salt and keys.
- Key—A 128-bit hexadecimal string that is used for frame encryption and decryption. The default value is zero.
- Salt —A 32-bit hexadecimal number that is used during encryption and decryption. The same salt must be configured on both sides of the connection to ensure proper communication. The default value is zero.
- Security Parameters Index (SPI) number—A 32-bit number that identifies the SA to be configured to the hardware. The range is from 256 to 4,294,967,295.
Support for AES Encryption
The Advanced Encryption Standard (AES) is the symmetric cipher algorithm that provides a high-level of security, and can accept different key sizes.
The Cisco TrustSec FC Link Encryption feature supports the 128-bit AES for security encryption and enables either AES-GCM or AES-GMAC for an interface. The AES-GCM mode provides encryption and authentication of the frames and AES-GMAC provides only the authentication of the frames that are being passed between the two peers.
Guidelines and Limitations
This section lists the guidelines for Cisco TrustSec FC Link Encryption:
- Ensure that Cisco TrustSec FC Link Encryption is enabled only between MDS switches. This feature is supported only on E-ports or the ISLs, and errors will result if non-MDS switches are used.
- Ensure that the peers in the connection have the same configurations. If there are differences in the configurations, a “port re-init limit exceeded” error message is displayed.
- Before applying the SA to the ingress and egress hardware of a switch interface, ensure that the interface is in the admin shut mode.
Configuring Cisco TrustSec Fibre Channel Link Encryption
By default, the FC-SP feature and the Cisco TrustSec FC Link Encryption feature are disabled in all switches in the Cisco MDS 9000 Family.
You must explicitly enable the FC-SP feature to access the configuration and verification commands for fabric authentication and encryption. When you disable this feature, all related configurations are automatically discarded.
Setting Up Security Association Parameters using DCNM-SAN
To perform encryption between the switches, a security association (SA) needs to be set up. An administrator manually configures the SA before the encryption can take place. The SA includes parameters such as keys and salt, that are required for encryption. You can set up to 2000 SAs in a switch. The no fcsp esp sa spi_number command returns an error saying that the SA is in use if the specified SA is currently programmed to the ports.
To determine which ports are using the SA, use the show running-config fcsp command.
Note |
Cisco TrustSec FC Link Encryption is currently supported only on DHCHAP on and off modes. |
To set up the SA parameters, such as keys and salt, using DCNM-SAN, follow these steps:
Procedure
| Step 1 |
Expand Switches > Security, and then select FC-SP (DHCHAP). You see the FC-SP configuration in the Information pane. |
| Step 2 |
Click the SA tab. You see the SA parameters for each switch. |
| Step 3 |
Click the Create Row icon. You see the Create SA Parameters dialog box. |
| Step 4 |
Select the switches on which you want to perform an encryption. |
| Step 5 |
Select a value for the SP. The range is from 256 to 65536. |
| Step 6 |
Enter a value for the salt. Alternatively, click Salt Generator to select a value. |
| Step 7 |
Enter a value for the key. Alternatively, click Key Generator to select a value. |
| Step 8 |
Click Create to save the changes. |
Setting Up Security Association Parameters using Device Manager
To set up the SA parameters, such as keys and salt, using Device Manager, follow these steps:
Procedure
| Step 1 |
Choose Switches > Security, and then select FC-SP. You see the FC-SP configuration dialog box. |
| Step 2 |
Click SA tab. You see the SA parameters for each switch. |
| Step 3 |
Click Create to create new parameters. You see the Create FC-SP SA dialog box. |
| Step 4 |
Select a value for the SP. The range is from 256 to 65536. |
| Step 5 |
Enter a value for the salt. Alternatively, click Salt Generator to select a value |
| Step 6 |
Enter a value for the key. Alternatively, click Key Generator to select a value. |
| Step 7 |
Click Create to save the changes. |
Setting Up Security Association Parameters using Device Manager
To set up the SA parameters, such as keys and salt, using Device Manager, follow these steps:
Procedure
| Step 1 |
Choose Switches > Security, and then select FC-SP. You see the FC-SP configuration dialog box. |
| Step 2 |
Click SA tab. You see the SA parameters for each switch. |
| Step 3 |
Click Create to create new parameters. You see the Create FC-SP SA dialog box. |
| Step 4 |
Select a value for the SP. The range is from 256 to 65536. |
| Step 5 |
Enter a value for the salt. Alternatively, click Salt Generator to select a value |
| Step 6 |
Enter a value for the key. Alternatively, click Key Generator to select a value. |
| Step 7 |
Click Create to save the changes. |
Configuring ESP Settings
Once the SA is created, you need to configure Encapsulating Security Protocol (ESP) on the ports. You should specify the egress and ingress ports for the encryption and decryption of packets between the network peers. The egress SA specifies which keys or parameters are to be used for encrypting the packets that leave the switch. The ingress SA specifies which keys or parameters are to be used to decrypt the packets entering that particular port.
Configuring ESP Modes
Configure the ESP settings for the ports as GCM to enable message authentication and encryption or as GMAC to enable message authentication.
The default ESP mode is AES-GCM.
This section covers the following topics:
Configuring AES-GMAC
Procedure
| Step 1 |
Expand Switches > Security, and then select FC-SP (DHCHAP). You see the FC-SP configuration in the Information pane. |
| Step 2 |
Click the ESP Interfaces tab. You see the Interface details for each switch. |
| Step 3 |
Click the Create Row icon. You see the Create ESP Interfaces dialog box. |
| Step 4 |
Select the switches on which you want to perform an encryption. |
| Step 5 |
Enter an interface for the selected switch. |
| Step 6 |
Select the appropriate ESP mode for the encryption. |
| Step 7 |
Enter the appropriate egress port for the encryption. |
| Step 8 |
Enter the appropriate ingress port for the encryption. |
| Step 9 |
Click Create to save the changes. |
Configuring AES-GMAC using Device Manager
To configure ESP settings using Device Manager, follow these steps:
Procedure
| Step 1 |
Expand Switches > Security, and then select FC-SP. You see the FC-SP configuration dialog box. |
| Step 2 |
Click the ESP Interfaces tab. You see the Interface details for each switch. |
| Step 3 |
Click Create. You see the Create FC-SP ESP Interfaces dialog box. |
| Step 4 |
Enter an interface for any switch for encryption. Alternatively, you can select values from the available interfaces for the selected switch. |
| Step 5 |
Select the appropriate ESP mode for the encryption. |
| Step 6 |
Enter the appropriate egress port for the encryption. |
| Step 7 |
Enter the appropriate ingress port for the encryption. |
| Step 8 |
Click Create to save the changes. |
Configuring ESP Using ESP Wizard
You can configure and set up link-level encryption between switches using ESP wizard. You can configure an existing Inter-Switch Link (ISL) as a secure ISL or edit an existing secure ingress SPI and egress SPI using this wizard.
To configure ESP using ESP wizard, follow these steps:
Procedure
| Step 1 |
Right-click Tools > Security> FC-SP ESP Link Security to launch the ESP wizard from DCNM-SAN. |
||
| Step 2 |
Select the appropriate ISL to secure or edit security.
|
||
| Step 3 |
Create new Security Associations (SAs). You can create a new SA for each switch or use the existing SAs. You can click View Existing SA to view the existing SAs.
|
||
| Step 4 |
Specify the Egress port, Ingress port, and ESP mode for the selected ISL. The Egress and Ingress ports are auto populated with SPIs of the SAs common to a pair of switches in case of a secured ISL. In this scenario, the mode is disabled and you cannot edit the modes for a secured ISL.
|
||
| Step 5 |
Review your configuration. |
||
| Step 6 |
Click Finish to start the configuration for the ESP setup. You can view the status of the configuration in the status column. |
Verifying Cisco TrustSec Fibre Channel Link Encryption Configuration
You can view information about the Cisco TrustSec FC Link Encryption feature using the show commands in DCNM-SAN or Device Manager.
|
Command |
Purpose |
|---|---|
|
show fcsp interface fc7/41 |
Displays all FC-SP-related information for a specific interface. |
|
show running-config fcsp |
Displays all the run-time information relevant to FC-SP. |
|
show fcsp interface fc3/31 statistics |
Displays all statistics related to DHCHAP and ESP for an interface. |
For detailed information about the fields in the output from these commands, refer to the Cisco MDS 9000 Family Command Reference .
This section has the following topics:
Displaying FC-SP Interface Statistics
You can view the statistics data that displays the Encapsulating Security Protocol-ESP Security Parameter (SPI) mismatches and Interface-Encapsulating Security Protocol authentication failures information using DCNM-SAN.
To view the ESP statistics for an interface, follow these steps:
Procedure
| Step 1 |
Expand Interfaces > FC Physical, and then select FC-SP. You see the FC-SP configuration in the Information pane. |
| Step 2 |
Click the FC-SP tab. You see view the FC-SP statistics data in the Information pane. |
| Step 3 |
Click Refresh to refresh the statistics data. |
Displaying FC-SP Interface Statistics Using Device Manager
To view the ESP statistics for an interface using Device Manager, follow these steps:
Procedure
| Step 1 |
Choose Security > FC Physical, and then select FC-SP. You see the FC-SP configuration in the Information pane. |
| Step 2 |
Click the Statistics tab. You see the statistics in the Information pane. |
| Step 3 |
Click Refresh to refresh the statistics data. |
Feedback