Cisco Cisco IPS 4255 Sensor
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Release Notes for Cisco Intrusion Prevention System 7.0(7)E4
OL-25390-01
Restrictions and Limitations
Restrictions and Limitations
The following restrictions and limitations apply to Cisco IPS 7.0(7)E4 software and the products that
run it:
run it:
•
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.
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.
•
Anomaly detection does not support IPv6 traffic; only IPv4 traffic is directed to the anomaly
detection processor.
detection processor.
•
IPv6 does not support the following event actions: Request Block Host, Request Block Connection,
or Request Rate Limit.
or Request Rate Limit.
•
The AIM IPS and the NME IPS do not support the IPv6 features, because the router in which they
are installed does not send them IPv6 data. IPv6 inspection is also not supported on the IDSM2. The
switch is able to send IPv6 packets to the IDSM2, but this has not been tested and is not officially
supported. There is no support for IPv6 on the management (command and control) interface. With
ASA 8.2.1, the AIP SSM supports IPv6 features.
are installed does not send them IPv6 data. IPv6 inspection is also not supported on the IDSM2. The
switch is able to send IPv6 packets to the IDSM2, but this has not been tested and is not officially
supported. There is no support for IPv6 on the management (command and control) interface. With
ASA 8.2.1, the AIP SSM supports IPv6 features.
•
VACLs on Catalyst switches do not have IPv6 support. The most common method for copying traffic
to a sensor configured in promiscuous mode is to use VACL capture. If you want to have IPv6
support, you can use SPAN ports.
to a sensor configured in promiscuous mode is to use VACL capture. If you want to have IPv6
support, you can use SPAN ports.
•
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.
ICMP signature engine. ICMPv6 is covered by the Atomic IP Advanced signature engine.
•
CSM and MARS do not support IPv6.
•
The AIM IPS and the NME IPS do not support virtualization.
•
When you reload the router, the AIM IPS and the NME IPS also reload. To ensure that there is no
loss of data on the AIM IPS or the NME IPS, make sure you shut down the module using the
shutdown command before you use the reload command to reboot the router.
loss of data on the AIM IPS or the NME IPS, make sure you shut down the module using the
shutdown command before you use the reload command to reboot the router.
•
Do not deploy IOS IPS and the and the NME IPS at the same time.
•
When the AIM IPS and the NME IPS are used with an IOS firewall, make sure SYN flood
prevention is done by the IOS firewall.
prevention is done by the IOS firewall.
The AIM IPS, the NME IPS, and the IOS firewall complement abilities of each other to create
security zones in the network and inspect traffic in those zones. Because the AIM IPS, the NME IPS,
and the IOS firewall operate independently, sometimes they are unaware of the activities of the other.
In this situation, the IOS firewall is the best defense against a SYN flood attack.
security zones in the network and inspect traffic in those zones. Because the AIM IPS, the NME IPS,
and the IOS firewall operate independently, sometimes they are unaware of the activities of the other.
In this situation, the IOS firewall is the best defense against a SYN flood attack.
•
Cisco access routers only support one IDS/IPS per router.
•
On IPS sensors with multiple processors (for example, the IPS 4260 and IPS 4270-20), packets may
be captured out of order in the IP logs and by the packet command. Because the packets are not
processed using a single processor, the packets can become out of sync when received from multiple
processors.
be captured out of order in the IP logs and by the packet command. Because the packets are not
processed using a single processor, the packets can become out of sync when received from multiple
processors.
•
An IPS appliance can support both promiscuous and inline monitoring at the same time; however
you must configure each physical interface in either promiscuous or inline mode. The sensor must
contain at least two physical sensing interfaces to perform both promiscuous and inline monitoring.
The exceptions to this are the AIP SSM-10, AIP SSM-20, and AIP SSM-40. The AIP SSM can
support both promiscuous and inline monitoring on its single physical back plane interface inside
you must configure each physical interface in either promiscuous or inline mode. The sensor must
contain at least two physical sensing interfaces to perform both promiscuous and inline monitoring.
The exceptions to this are the AIP SSM-10, AIP SSM-20, and AIP SSM-40. The AIP SSM can
support both promiscuous and inline monitoring on its single physical back plane interface inside