Cisco Cisco IPS 4255 Sensor

Anomaly detection does not support IPv6 traffic; only IPv4 traffic is directed to the anomaly 
detection processor.

IPv6 does not support the following event actions: Request Block Host, Request Block Connection, 
or Request Rate Limit.

Global correlation does not support IPv6.

There is no support for IPv6 on the management (command and control) interface.

ICMP signature engines do not support ICMPv6, they are IPv4-specific, for example, the Traffic 
ICMP signature engine. ICMPv6 is covered by the Atomic IP Advanced signature engine.

CSM and MARS do not support IPv6.

When deploying an IPS sensor monitoring two sides of a network device that does TCP sequence 
number randomization, we recommend using a virtual senor for each side of the device. 

For IPS 5.0 and later, you can no longer remove the cisco account. You can disable it using the no 
password cisco command, but you cannot remove it. To use the no password cisco command, there 
must be another administrator account on the sensor. Removing the cisco account through the 
service account is not supported. If you remove the cisco account through the service account, the 
sensor most likely will not boot up, so to recover the sensor you must reinstall the sensor system 
image.

After you upgrade any IPS software on your sensor, you must restart the IDM to see the latest 
software features. 

The IDM does not support any non-English characters, such as the German umlaut or any other 
special language characters. If you enter such characters as a part of an object name through IDM, 
they are turned into something unrecognizable and you will not be able to delete or edit the resulting 
object through IDM or the CLI. This is true for any string that is used by the CLI as an identifier, 
for example, names of time periods, inspect maps, server and URL lists, and interfaces.

When SensorApp is reconfigured, there is a short period when SensorApp is unable to respond to 
any queries. Wait a few minutes after reconfiguration is complete before querying SensorApp for 
additional information. 

The IDM and IME launch MySDN from the last browser window you opened, which is the default 
setting for Windows. To change this default behavior, in Internet Explorer, choose Tools > Internet 
Options, and then click the Advanced tab. Scroll down and uncheck the Reuse windows for 
launching shortcuts check box.

This section lists the resolved and unresolved caveats, and contains the following topics: 

The following known issues are resolved in the 7.1(8)E4 release:

CSCty68417  Orphaned User Sessions When Adding Authorized Key With RADIUS Enabled 

CSCtq32936  IPS crashes if signature auto-update is enabled without the license