New hardware and enhancements to\u00a0Cisco\u2019s\u00a0software products will make computer networks more resilient to attack, the company said Tuesday.Cisco unveiled VPN hardware and new features for the Internetwork Operating System (IOS) and Security Device Manager software to support firewalls and spot the source of denial-of-service (DoS) attacks. The new products and features are part of Cisco's Self-Defending Network strategy to create "autonomic" responses to network security threats, the company said.On the hardware side, Cisco extended VPN support to the 7301 Router, allowing that device to support 370M bit\/sec VPN throughput in addition to firewall, routing and quality-of-service management features, the company said.Cisco also added a device to its 3000 line of VPN concentrators: the VPN 3020 Concentrator. That device has integrated IPSec and Secure Sockets Layer (SSL) remote access features and can support up to 750 concurrent VPN users using IPSec and up to 200 users in SSL mode, Cisco said.On the software front, Cisco unveiled a number of security features that come with IOS Software Release 12.3T.The IP Source Tracker is an IOS-based security tool that allows IT managers to access Cisco routers using a special "management channel" even when they are the target of a DoS attack. New command-line interface features in IOS give administrators more control over access to security operations by allowing them to restrict access to features based on administrative roles, Cisco said.The company also announced better firewall support from IOS that will enable IT administrators to divide their network into "trust zones" based on IP addresses. Also, a new software product, the Cisco IOS Firewall for IPv6, supports inspection of both IPv4 and IPv6 traffic and protocol anomaly inspection, Cisco said.IPv6 is a new IP version formalized in a set of specifications from the Internet Engineering Task Force. Among other things, IPv6 lengthens IP addresses from 32 to 128 bits, which will accommodate a new generation of "networked" devices.A new version of the Cisco Security Device Manager features start-up wizards that make it easier to deploy security products, update Cisco router configurations and lock down network security. Security Device Manager version 1.1 also extends support to the Cisco 7200 series router, the company said.Cisco faces tougher competition on the security front following the February announcement that chief competitor Juniper Networks\u00a0is buying\u00a0firewall giant NetScreen Technologies.The San Jose company has been working in recent months to raise its security profile, announcing a number of security initiatives.In November, Cisco and leading anti-virus companies\u00a0announced\u00a0the Cisco Network Admission Control program that enables Cisco routers to evaluate information, such as whether a particular computer's anti-virus definitions are up to date and its operating system is adequately patched, before allowing it to connect to a network. In February, the company said\u00a0it is collaborating with IBM\u00a0to let IBM's products communicate more directly with Cisco's network security technology.