Security Features Overview


Security is a term that covers several different aspects of network use and operation.

One general type of security is control of the devices or users that can access the network. Ways of doing this include authenticating the user at the point of logging in, controlling access by defining limits on certain types of traffic, or protecting the operation of the switch itself. Security measures in this last category include routing policies that can limit the visibility of parts of the network or denial of service protection that prevents the CPU from being overloaded. Finally, management functions for the switch can be protected from unauthorized use. This type of protection uses various types of user authentication.

Security Modes

For information on ExtremeXOS security modes, see Security Mode Overview.

Security Features

ExtremeXOS has enhanced security features designed to protect, rapidly detect, and correct anomalies in your network. Extreme Networks products incorporate a number of features designed to enhance the security of your network while resolving issues with minimal network disruption. No one feature can ensure security, but by using a number of features in concert, you can substantially improve the security of your network.

The following list provides a brief overview of some of the available security features:
  • ACL (Access Control List)s—ACLs are policy files used by the ACL application to perform packet filtering and forwarding decisions on incoming traffic and packets. Each packet arriving on an ingress port is compared to the ACL applied to that port and is either permitted or denied.

    For more information about using ACLs to control and limit network access, see Security.

  • CLEAR-Flow—CLEAR-Flow inspects Layer 2 and Layer 3 packets, isolates suspicious traffic, and enforces policy-based mitigation actions. Policy-based mitigation actions include the switch taking an immediate, predetermined action or sending a copy of the traffic off-switch for analysis. Working together, CLEAR-Flow and Sentriant™ provide a rapid response to network threats. For off-switch analysis, CLEAR-Flow sends the suspicious traffic to Sentriant and Sentriant stops the threats.

    For more information about CLEAR-Flow, see CLEAR-Flow. For more information about Sentriant, contact your Extreme Networks representative.

  • Denial of Service Protection—DoS protection is a dynamic response mechanism used by the switch to prevent critical network or computing resources from being overwhelmed and rendered inoperative. In essence, DoS protection protects the switch, CPU, and memory from attacks and attempts to characterize the attack (or problem) and filter out the offending traffic so that other functions can continue. If the switch determines it is under attack, the switch reviews the packets in the input buffer and assembles ACLs that automatically stop the offending packets from reaching the CPU. For increased security, you can enable DoS protection and establish CLEAR-Flow rules at the same time.

    For more information about DoS attacks and DoS protection, see Denial of Service Protection.

  • Network Login—Controls the admission of user packets and access rights thereby preventing unauthorized access to the network. Network login is controlled on a per port basis. When network login is enabled on a port in a VLAN, that port does not forward any packets until authentication takes place. Network login is capable of three types of authentication: web-based, MAC-based, and 802.1X.

    For more information about network login, see Network Login.

  • Policy Files—Text files that contain a series of rule entries describing match conditions and actions to take. Policy files are used by both routing protocol applications (routing policies) and the ACL application (ACLs).

    For more information about policy files, see Routing Policies.

  • Routing Policies—Policy files used by routing protocol applications to control the advertisement, reception, and use of routing information by the switch. By using policies, a set of routes can be selectively permitted or denied based on their attributes for advertisements in the routing domain. Routing policies can be used to “hide” entire networks or to trust only specific sources for routes or ranges of routes.

    For more information about using routing policies to control and limit network access, see .

  • sFlow—A technology designed to monitor network traffic by using a statistical sampling of packets received on each port. sFlow also uses IP headers to gather information about the network. By gathering statistics about the network, sFlow becomes an early warning system, notifying you when there is a spike in traffic activity. Upon analysis, common response mechanisms include applying an ACL, changing Quality of Service (QoS) parameters, or modifying VLAN settings.

    For more information, see Using sFlow.