Cisco TrustSec enables organizations to secure their networks and services through identity-based access control to anyone, anywhere, anytime. The solution also offers data integrity and confidentiality services, policy-based governance, and centralized monitoring, troubleshooting, and reporting services. TrustSec can be combined with personalized, professional service offerings to simplify solution deployment and management, and is a foundational security component to Cisco Borderless Networks.
The Cisco TrustSec security architecture builds secure networks by establishing domains of trusted network devices. Each device in the domain is authenticated by its peers. Communication on the links between devices in the domain is secured with a combination of encryption, message integrity check, and data-path replay protection mechanisms. Cisco TrustSec uses the device and user credentials acquired during authentication for classifying the packets by security groups (SGs) as they enter the network. This packet classification is maintained by tagging packets on ingress to the Cisco TrustSec network so that they can be correctly identified to apply security and other policy criteria along the data path. The tag, called the security group tag (SGT), allows the network to enforce the access control policy by enabling the endpoint device to act upon the SGT to filter traffic.
One of the components of Cisco TrustSec architecture is the security group-based access control. In the security group-based access control component, access policies in the Cisco TrustSec domain are topology-independent, based on the roles (as indicated by security group number) of source and destination devices rather than on network addresses. Individual packets are tagged with the security group number of the source.
Cisco devices use the SGT Exchange Protocol (SXP) to propagate SGTs across network devices that do not have hardware support for Cisco TrustSec. SXP is the software solution to avoid CTS hardware upgrade on all switches. WLC will be supporting SXP as part of TrustSec Architecture. The SXP sends SGT information to the CTS-enabled switches so that appropriate role-based access control lists (RBACLs) can be activated depending on the role information represented by the SGT. By default, the controller always works in the Speaker mode. To implement the SXP on a network, only the egress distribution switch needs to be CTS-enabled, and all the other switches can be non-CTS-capable switches.
The SXP runs between any access layer and distribution switch or between two distribution switches. The SXP uses TCP as the transport layer. CTS authentication is performed for any host (client) joining the network on the access layer switch similar to an access switch with CTS-enabled hardware. The access layer switch is not CTS hardware enabled. Therefore, data traffic is not encrypted or cryptographically authenticated when it passes through the access layer switch. The SXP is used to pass the IP address of the authenticated device, that is a wireless client, and the corresponding SGT up to the distribution switch. If the distribution switch is CTS hardware enabled, the switch inserts the SGT into the packet on behalf of the access layer switch. If the distribution switch is not CTS hardware enabled, the SXP on the distribution switch passes the IP-SGT mapping to all the distribution switches that have CTS hardware. On the egress side, the enforcement of the RBACL occurs at the egress L3 interface on the distribution switch.
The following are some guidelines for Cisco TrustSec SXP:
- SXP is supported on the following security policies only:
- 802.1x (Dynamic WEP)
- MAC Filtering using RADIUS servers
- Web authentication using RADIUS servers for user authentication
- SXP is supported for both IPv4 and IPv6 clients.
- Controller always operates in the Speaker mode.
For more information about Cisco TrustSec, see http://www.cisco.com/en/US/netsol/ns1051/index.html.