Cisco Cisco IPS 4255 Sensor

New Event Actions

Two new deny attacker event actions have been added in the 5.1(7)E1 release: Deny Attacker Service 
Pair Inline and Deny Attacker Victim Pair Inline. A new Request Rate Limit event action with a 
parameter that lets you specify a percentage of traffic from a denied attacker has been added to 
support rate limiting.

GRE/IPV4-in-IPV4 Tunneling

IPS 5.1(7)E1 sensors can now monitor GRE and IPV4-inIPV4 encapsulated traffic.

For detailed information on the new naming conventions, see 

The Cisco Security Intelligence Operations site on Cisco.com provides intelligence reports about current 
vulnerabilities and security threats. It also has reports on other security topics that help you protect your 
network and deploy your security systems to reduce organizational risk.

You should be aware of the most recent security threats so that you can most effectively secure and 
manage your network. Cisco Security Intelligence Operations contains the top ten intelligence reports 
listed by date, severity, urgency, and whether there is a new signature available to deal with the threat.

Cisco Security Intelligence Operations contains a Security News section that lists security articles of 
interest. There are related security tools and links.

You can access Cisco Security Intelligence Operations at this URL:

Cisco Security Intelligence Operations is also a repository of information for individual signatures, 
including signature ID, type, structure, and description.

You can search for security alerts and signatures at this URL:

This section describes what to do before upgrading your sensor, and contains the following topics: