of IPS in CityU
following section, we shall introduce the features of the
IPS deployed in CityU. With the help of real examples, it
shows how the IPS can protect the CityU from daily Internet
Detect and Report Intrusion in Real Time
of the IPS is to detect intrusion once it is detected. As
it needs only a few packets to compromise a system, the IPS
must block the attack in real time. On the other hand, not
all detected intrusions are critical, some of them are informational
and there is no need to block the traffic. As a result, we
need an interface to define the policy of the IPS. Based on
the severity of the attacks, we can report, log or drop the
intrusion based on our pre-defined IPS policy.
in Figure 1-1, a network administrator can define the
blocking policy for each intrusion. Different policies can
be applied for both inbound and outbound attacks.
Figure 1-1 Policy Editor to define IPS policy (The above policy
will drop Incoming MyDoom.S Worm)
on the defined policy, the IPS will detect and block the intrusions
accordingly. A real-time console will display the detected
attacks as shown in Figure 1-2 below.
Figure 1-2 Real Time detection of Intrusion
Provide a flexible and configurable real time console for
attack Query and Correlation
there are so many intrusions detected everyday, we need a
flexible and configurable interface for the display, query
and backtrack of the attack database. An example of the real-time
console has already been shown in Figure 1-2.
intrusions can be identified according to protocols, OS, severity,
direction, source IP address, destination IP address; the
real-time console should be able to manipulate the attack
database based on these properties. This feature is shown
in Figure 2-1 below.
2-1 Attacks in Real-Time Console can be manipulated according
to different fields
the attacks may have worked in sequence in order to compromise
a system. We may want to group or drill down some of the inter-related
packets in order to study the attacking mechanism. Figure
2-2 shows how the real-time console of the IPS can provide
2-2 DrillDown View of an attack (Blocked->Inbound->MyDoom.S
Protect against DDoS attack
Denial of Service (DDoS) is an attack
that makes use of a large number of hosts to generate many
simple but fast network packets to a few hosts. This results
in a large volume of network traffic or connections reaching
the destination host(s) which render the target machine(s)
run out of its capacity to handle its normal services - a
denial of services.
before, every single attack in a DDoS is very simple and would
not be normally classified as an attack. In order to detect
such an attack, IPS will need to baseline normal traffic volume
and report a DDoS attack once the traffic deviate greatly
from the normal traffic. Figure 3 illustrates how the
IPS detects a DDoS attack.
3 DDoS detection mechanism - referring to baseline traffic
Automatic update of attack Signatures
anti-virus software which requires the latest virus signatures
to protect against new viruses, IPS also needs to update the
attack signatures from time to time. This should be done automatically
and transparently to the network administrator. The scheduled
updates of signatures are shown in Figure 4 below.
4 Scheduled Tasks to update attack signature automatically
Capture attack packets
to study the details of intrusion and provide evidence for
the attacks, it is very important to capture the attack packets
for further reference. Figure 5 shows just how it can
be achieved in the IPS.
5 Intrusion detected can be captured and displayed using Sniffer
Generate Management and Summary reports
management system must provide both summary and detailed reports
to record jobs done. The IPS provides both real-time and scheduled
reports to network administrators based on the attacks stored
in the attack database. The generated reports can be displayed
as HTML documents or saved as PDF files.
the wide spreading of viruses, worms over the Internet, the
security protection at the CityU Internet gateway was indeed
a very serious concern. In view of this, the CSC had deployed
a number of measures and the latest technologies to handle
the Internet security issue.
of both firewall and the newly deployed IPS has shown that
many Internet attacks have been successfully blocked. This
results in a more reliable and secure Internet environment
for all users of CityU.
everyone in CityU should also take the responsibility to protect
his/her own computers by applying the latest patches, updating
the latest antivirus software, etc. This simple but important
measure is always the key to enhance the total secure level
of the CityU network and thus improves the productivity of
all members of the CityU.