MacSec是什么

Understanding Media Access Control Security (MACsec)

Media Access Control Security (MACsec) is an 802.1AE IEEE industry-standard security technology that provides secure communication for all traffic on Ethernet links. MACsec provides point-to-point security on Ethernet links between directly connected nodes and is capable of identifying and preventing most security threats, including denial of service, intrusion, man-in-the-middle, masquerading, passive wiretapping, and playback attacks.

MACsec allows you to secure an Ethernet link for almost all traffic, including frames from the Link Layer Discovery Protocol (LLDP), Link Aggregation Control Protocol (LACP), Dynamic Host Configuration Protocol (DHCP), Address Resolution Protocol (ARP), and other protocols that are not typically secured on an Ethernet link because of limitations with other security solutions. MACsec can be used in combination with other security protocols such as IP Security (IPsec) and Secure Sockets Layer (SSL) to provide end-to-end network security.

MACsec is standardized in IEEE 802.1AE. The IEEE 802.1AE standard can be seen on the IEEE organization website at IEEE 802.1: BRIDGING & MANAGEMENT.

This topic contains the following sections:

• How MACsec Works
• Understanding Connectivity Associations and Secure Channels
• Understanding MACsec Security Modes
• Understanding the Requirements to Enable MACsec on a Switch-to-Host Link
• MACsec Hardware and Software Support Summary
• Understanding MACsec Hardware Requirements for EX Series and QFX Series Switches
• Understanding MACsec Software Requirements for EX Series and QFX Series Switches
• Understanding the MACsec Feature License Requirement
• MACsec Limitations

How MACsec Works

MACsec provides industry-standard security through the use of secured point-to-point Ethernet links. The point-to-point links are secured after matching security keys—a user-configured pre-shared key when you enable MACsec using static connectivity association key (CAK) security mode, a user-configured static secure association key when you enable MACsec using static secure association key (SAK) security mode, or a dynamic key included as part of the AAA handshake with the RADIUS server when you enable MACsec using dynamic security mode—are exchanged and verified between the interfaces at each end of the point-to-point Ethernet link. Other user-configurable parameters, such as MAC address or port, must also match on the interfaces on each side of the link to enable MACsec. See Configuring Media Access Control Security (MACsec).

Once MACsec is enabled on a point-to-point Ethernet link, all traffic traversing the link is MACsec-secured through the use of data integrity checks and, if configured, encryption.

The data integrity checks verify the integrity of the data. MACsec appends an 8-byte header and a 16-byte tail to all Ethernet frames traversing the MACsec-secured point-to-point Ethernet link, and the header and tail are checked by the receiving interface to ensure that the data was not compromised while traversing the link. If the data integrity check detects anything irregular about the traffic, the traffic is dropped.

MACsec can also be used to encrypt all traffic on the Ethernet link. The encryption used by MACsec ensures that the data in the Ethernet frame cannot be viewed by anybody monitoring traffic on the link. MACsec encryption is optional and user-configurable; you can enable MACsec to ensure the data integrity checks are performed while still sending unencrypted data “in the clear” over the MACsec-secured link, if desired.

MACsec is configured on point-to-point Ethernet links between MACsec-capable interfaces. If you want to enable MACsec on multiple Ethernet links, you must configure MACsec individually on each point-to-point Ethernet link.

Understanding Connectivity Associations and Secure Channels

MACsec is configured in connectivity associations. MACsec is enabled when a connectivity association is assigned to an interface.

When you are configuring MACsec using static secure association key (SAK) security mode, you must configure secure channels within a connectivity association. The secure channels are responsible for transmitting and receiving data on the MACsec-enabled link, and also responsible for transmitting SAKs across the link to enable and maintain MACsec. A single secure channel is unidirectional—it can be used to apply MACsec only to either inbound or outbound traffic. A typical connectivity association when MACsec is enabled using SAK security mode contains two secure channels—one secure channel for inbound traffic and another secure channel for outbound traffic.

When you enable MACsec using static CAK or dynamic security mode, you have to create and configure a connectivity association. Two secure channels—one secure channel for inbound traffic and another secure channel for outbound traffic—are automatically created. The automatically-created secure channels do not have any user-configurable parameters; all configuration is done in the connectivity association outside of the secure channels.

Understanding MACsec Security Modes

Understanding Static Connectivity Association Key Security Mode (Recommended Security Mode for Switch-to-Switch Links)

When you enable MACsec using static connectivity association key (CAK) security mode, two security keys—a connectivity association key (CAK) that secures control plane traffic and a randomly-generated secure association key (SAK) that secures data plane traffic—are used to secure the point-to-point Ethernet link. Both keys are regularly exchanged between both devices on each end of the point-to-point Ethernet link to ensure link security.

MACsec开启CAK模式时，需要两个key来保证P2P的网络安全:1.CAK--保证控制层traffic安全; 2. SAK--保证数据traffic安全；

You initially establish a MACsec-secured link using a pre-shared key when you are using static CAK security mode to enable MACsec. A pre-shared key includes a connectivity association name (CKN) and its own connectivity association key (CAK). The CKN and CAK are configured by the user in the connectivity association and must match on both ends of the link to initially enable MACsec.

Once matching pre-shared keys are successfully exchanged, the MACsec Key Agreement (MKA) protocol is enabled. The MKA protocol is responsible for maintaining MACsec on the link, and decides which switch on the point-to-point link becomes the key server. The key server then creates an SAK that is shared with the switch at the other end of the point-to-point link only, and that SAK is used to secure all data traffic traversing the link. The key server will continue to periodically create and share a randomly-created SAK over the point-to-point link for as long as MACsec is enabled.

You enable MACsec using static CAK security mode by configuring a connectivity association on both ends of the link. All configuration is done within the connectivity association but outside of the secure channel. Two secure channels—one for inbound traffic and one for outbound traffic—are automatically created when using static CAK security mode. The automatically-created secure channels do not have any user-configurable parameters that cannot already be configured in the connectivity association.

We recommend enabling MACsec on switch-to-switch links using static CAK security mode. Static CAK security mode ensures security by frequently refreshing to a new random security key and by sharing only the security key between the two devices on the MACsec-secured point-to-point link. Additionally, some optional MACsec features—replay protection, SCI tagging, and the ability to exclude traffic from MACsec—are available only when you enable MACsec using static CAK security mode.

See Configuring Media Access Control Security (MACsec) for step-by-step instructions on enabling MACsec using static CAK security mode.

Understanding Dynamic Secure Association Key Security Mode (Switch-to-Host Links)

Dynamic secure association key security mode is used to enable MACsec on a switch-to-host link.

To enable MACsec on a link connecting an endpoint device—such as a server, phone, or personal computer—to a switch, the endpoint device must support MACsec and must be running software that allows it to enable a MACsec-secured connection. When configuring MACsec on a switch-to-host link, the MACsec Key Agreement (MKA) keys, which are included as part of 802.1X authentication, are retrieved from a RADIUS server as part of the AAA handshake. A master key is passed from the RADIUS server to the switch and from the RADIUS server to the host in independent authentication transactions. The master key is then passed between the switch and the host to create a MACsec-secured connection.

A secure association using dynamic secure association security mode must be configured on the switch’s Ethernet interface that connects to the host in order for the switch to create a MACsec-secured connection after receiving the MKA keys from the RADIUS server.

The RADIUS server must be using Extensible Authentication Protocol-Transport Layer Security (EAP-TLS) in order to support MACsec. The RADIUS servers that support other widely-used authentication frameworks, such as password-only or md5, cannot be used to support MACsec. In order to enable MACsec on a switch to secure a connection to a host, you must be using 802.1X authentication on the RADIUS server. MACsec must be configured into dynamic mode. MACsec is still enabled using connectivity associations when enabled on a switch-to-host link, as it is on a switch-to-switch link.

Understanding Static Secure Association Key Security Mode (Supported for Switch-to-Switch Links)

When you enable MACsec using static secure association key (SAK) security mode, one of up to two manually configured SAKs is used to secure data traffic on the point-to-point Ethernet link. All SAK names and values are configured by the user; there is no key server or other tool that creates SAKs. Security is maintained on the point-to-point Ethernet link by periodically rotating between the two security keys. Each security key name and value must have a corresponding matching value on the interface at the other end of the point-to-point Ethernet link to maintain MACsec on the link.

You configure SAKs within secure channels when you enable MACsec using static SAK security mode. You configure secure channels within connectivity associations. A typical connectivity association for MACsec using static SAK security mode contains two secure channels—one for inbound traffic and one for outbound traffic—that have each been configured with two manually-configured SAKs. You must attach the connectivity association with the secure channel configurations to an interface to enable MACsec using static SAK security mode.

We recommend enabling MACsec using static CAK security mode. Use static SAK security mode only if you have a compelling reason to use it instead of static CAK security mode.

See Configuring Media Access Control Security (MACsec) for step-by-step instructions on enabling MACsec using SAKs.

Understanding the Requirements to Enable MACsec on a Switch-to-Host Link

When configuring MACsec on a switch-to-host link, the MACsec Key Agreement (MKA) keys, which are included as part of 802.1X authentication, are retrieved from a RADIUS server as part of the AAA handshake. A master key is passed from the RADIUS server to the switch and from the RADIUS server to the host in independent authentication transactions. The master key is then passed between the switch and the host to create a MACsec-secured connection.

The following requirements must be met in order to enable MACsec on a link connecting a host device to a switch.

The host device:

• must support MACsec and must be running software that allows it to enable a MACsec-secured connection with the switch.

The switch:

• must be an EX4200, EX4300, or EX4550 switch running Junos OS Release 14.1X53-D10 or later, or an EX9200 switch running Junos OS Release 15.1R1 or later. MACsec is supported on EX4200, EX4300, or EX4550 switches running Junos OS Release 14.1X53-D10 or later. MACsec is supported on EX9200 switches running Junos OS Release 15.1R1 or later.
• must be configured into dynamic secure association key security mode.
• must be using 802.1X authentication to communicate with the RADIUS server.

The RADIUS server:

• must be using the Extensible Authentication Protocol-Transport Layer Security (EAP-TLS) authentication framework.
  

  Note: RADIUS servers that support other widely-used authentication frameworks, such as password-only or md5, cannot be used to support MACsec.

• must be using 802.1X authentication.
• can be multiple hops from the switch and the host device.

MACsec Hardware and Software Support Summary

Table 1 summarizes MACsec hardware and software support for EX Series and QFX Series switches.

MACsec hardware and software support is discussed in greater detail in the remaining sections.

Table 1: MACsec Hardware and Software Support Summary for EX Series and QFX Series Switches

Switch

MACsec-capable Interfaces

Switch-to-Switch Support Introduction

Switch-to-Host Support Introduction

Required Software Package

EX4200

All uplink port connections on the SFP+ MACsec uplink module.

13.2X50-D15

14.1X53-D10

controlled

EX4300

All access and uplink ports.

13.2X50-D15

14.1X53-D10

controlled

EX4550

All EX4550 optical interfaces that use the LC connection type.

13.2X50-D15

14.1X53-D10

controlled

EX4600

All twenty-four fixed 1GbE SFP/10GbE SFP+ interfaces and all interfaces that support the copper Gigabit Interface Converter (GBIC).

All eight SFP+ interfaces on the EX4600-EM-8F expansion module.

14.1X53-D15

Not supported

controlled

EX9200

All forty SFP interfaces on the EX9200-40F-M line card.

All twenty SFP interfaces on the EX9200-20F-MIC installed in an EX9200-MPC line card.

Note: You can install up to two EX9200-20F-MIC MICs in an EX9200-MPC line card for a maximum of forty MACsec-capable interfaces.

All forty SFP+ interfaces on the EX9200-40XS.

15.1R1

15.1R1

Junos image

Note: MACsec is available on the Junos OS image in EX9200 switches only. MACsec is not available on the limited Junos OS image package.

QFX5100

All eight SFP+ interfaces on the EX4600-EM-8F expansion module.

14.1X53-D15

Not supported

controlled

Understanding MACsec Hardware Requirements for EX Series and QFX Series Switches

MACsec is currently supported on the following EX Series and QFX Series switch interfaces:

• The uplink port connections on the SFP+ MACsec uplink module that can be installed on EX4200 series switches.
• All access and uplink ports on EX4300 switches.
• All EX4550 optical interfaces that use the LC connection type. See Pluggable Transceivers Supported on EX4550 Switches.
• All twenty-four fixed 1GbE SFP/10GbE SFP+ interfaces on an EX4600 switch and all interfaces that support the copper Gigabit Interface Converter (GBIC).
• All eight SFP+ interfaces on the EX4600-EM-8F expansion module, when installed in an EX4600 or QFX5100-24Q switch.
  

  Note: MACsec is not supported on EX4600 or QFX5100-24Q switches in Junos OS Release 15.1.

  See Feature Explorer for a full listing of Junos OS releases that support MACsec.

• All forty SFP interfaces on the EX9200-40F-M line card, when the line card is installed in an EX9200 series switch.
• All twenty SFP interfaces on the EX9200-20F-MIC, when this modular interface card is installed in the EX9200-MPC line card of an EX9200 switch. You can install up to two EX9200-20F-MIC MICs in an EX9200-MPC line card, for a maximum of forty MACsec-capable interfaces.
• All forty SFP+ interfaces on the EX9200-40XS, when the line card in installed in an EX9200 switch.

MACsec can be configured on supported switch interfaces when those switches are configured in a Virtual Chassis or Virtual Chassis Fabric (VCF), including when MACsec-supported interfaces are on member switches in a mixed Virtual Chassis or VCF that includes switch interfaces that do not support MACsec. MACsec, however, cannot be enabled on Virtual Chassis ports (VCPs) to secure traffic travelling between member switches in a Virtual Chassis or VCF.

Understanding MACsec Software Requirements for EX Series and QFX Series Switches

See Feature Explorer for a full listing of Junos OS releases and platforms that support MACsec.

MACsec was initially released on EX4200, EX4300, and EX4550 switches in Junos OS Release 13.2X50-D15.

MACsec support for dynamic security mode, which allows MACsec to be configured on switch-to-host links, for EX4200, EX4300, and EX4550 switches was introduced in Junos OS Release 14.1X53-D10.

The switches on each end of a MACsec-secured switch-to-switch link must either both be using Junos OS Release 14.1X53-D10 or later, or must both be using an earlier version of Junos, in order to establish a MACsec-secured connection when using static CAK security mode.

MACsec support for EX4600 switches and QFX5100-24Q switches was introduced in Junos OS Release 14.1X53-D15. The EX4600 and QFX5100-24Q switches supports MACsec on switch-to-switch links only.

Note: MACsec is not supported on EX4600 or QFX5100-24Q switches in Junos OS Release 15.1.

See Feature Explorer for a full listing of Junos OS releases and platforms that support MACsec.

MACsec support for EX9200 switches for both switch-to-switch links and for switch-to-host links was introduced in Junos OS Release 15.1R1. The EX9200-40F-M line card, EX9200-20F-MIC installed in an EX9200-MPC line card, and the EX9200-40XS line card support MACsec with AES-128 bit encryption, providing support for link-layer data confidentiality, data integrity, and data origin authentication. You must apply a single license—EX9200-SFL—to enable MACsec.

You must download the controlled version of your Junos OS software to enable MACsec on EX4200, EX4300, EX4550, EX4600, or QFX5100-24Q switches. MACsec support is not available in the domestic version of your Junos OS software on these platforms.

You must download the standard Junos image to enable MACsec on EX9200 switches. MACsec is not supported on the limited image.

The controlled version of Junos OS software for EX4200, EX4300, EX4550, EX4600, or QFX5100-24Q switches includes all features and functionality available in the domestic version of Junos OS, while also supporting MACsec. The domestic version of Junos OS software is shipped on all switches that support MACsec, so you must download and install a controlled version of Junos OS software for your switch before you can enable MACsec.

The controlled version of Junos OS software for EX4200, EX4300, EX4550, EX4600, or QFX5100-24Q switches contains encryption and is, therefore, not available to customers in all geographies. The export and re-export of the controlled version of Junos OS software is strictly controlled under United States export laws. The export, import, and use of the controlled version of Junos OS software is also subject to controls imposed under the laws of other countries. If you have questions about acquiring the controlled version of your Junos OS software, contact Juniper Networks Trade Compliance group at [e-mail].

The standard version of Junos OS software for EX9200 switches contains encryption and is, therefore, not available to customers in all geographies. The export and re-export of this Junos OS software is strictly controlled under United States export laws. The export, import, and use of this Junos OS software is also subject to controls imposed under the laws of other countries. If you have questions about acquiring this version of your Junos OS software, contact Juniper Networks Trade Compliance group at [e-mail].

Understanding the MACsec Feature License Requirement

A feature license is required to configure MACsec on a switch.

To purchase a feature license for MACsec, contact your Juniper Networks sales representative (http://www.juniper.net/us/en/contact-us/sales-offices). The Juniper sales representative will provide you with a feature license file and a license key. You will be asked to supply the chassis serial number of your switch; you can obtain the serial number by running the show chassis hardware command.

The MACsec feature license is an independent feature license; the feature licenses that must be purchased to enable other groups of features on your switches cannot be purchased to enable MACsec.

MACsec Limitations

All types of Spanning Tree Protocol frames cannot currently be encrypted using MACsec.

Release History Table

Release

Description

15.R1

MACsec is supported on EX9200 switches running Junos OS Release 15.1R1 or later.

14.1X53-D15

MACsec support for EX4600 switches and QFX5100-24Q switches was introduced in Junos OS Release 14.1X53-D15.

14.1X53-D10

MACsec is supported on EX4200, EX4300, or EX4550 switches running Junos OS Release 14.1X53-D10 or later.

14.1X53-D10

MACsec support for dynamic security mode, which allows MACsec to be configured on switch-to-host links, for EX4200, EX4300, and EX4550 switches was introduced in Junos OS Release 14.1X53-D10.

13.2X50-D15

MACsec was initially released on EX4200, EX4300, and EX4550 switches in Junos OS Release 13.2X50-D15.

Modified: 2017-01-24