Configure IOS Intrusion Prevention System (IPS) using CLI
发表时间:2010-9-12 评论:0 点击 6,443+
Instructor Version
Topology Diagram
Addressing Table
Device | Interface IP Address | Subnet Mask | Default Gateway |
R1 | FA0/0 192.168.1.1 | 255.255.255.0 | N/A |
S0/0/0 10.1.1.1 | 255.255.255.0 | N/A | |
R2 | S0/0/0 (DCE) 10.1.1.2 | 255.255.255.0 | N/A |
S0/0/1 (DCE) 10.2.2.1 | 255.255.255.0 | N/A | |
R3 | FA0/0 192.168.3.1 | 255.255.255.0 | N/A |
S0/0/0 10.2.2.2 | 255.255.255.0 | N/A | |
Syslog Server | NIC 192.168.1.50 | 255.255.255.0 | 192.168.1.1 |
PC-A | NIC 192.168.1.2 | 255.255.255.0 | 192.168.1.1 |
PC-C | NIC 192.168.3.2 | 255.255.255.0 | 192.168.3.1 |
Learning Objectives
Enable IOS IPS.
Configure logging.
Modify an IPS signature.
Verify IPS.
Introduction
Your task is to configure router R1 for IPS in order to scan traffic entering the
192.168.1.0 network.
The server labeled ‘Syslog Server’ is used to log IPS messages. You must configure the
router to identify the syslog server in order to receive logging messages. Displaying
the correct time and date in syslog messages is vital when using syslog to monitor the
network. Set the clock and configure timestamp service for logging on the routers.
Finally, enable IPS to produce an alert and drop ICMP echo reply packets inline.
The server and PCs have been preconfigured. The routers have also been preconfigured
with the following:
Enable password: ciscoenpa55
Console password: ciscoconpa55
VTY line password: ciscovtypa55
EIGRP 101
Task 1: Enable IOS IPS
Note: Within Packet Tracer, the routers already have the signature files imported and in
place. They are the default xml files in flash. For this reason, it is not necessary to
configure the public crypto key and complete a manual import of the signature files.
S tep 1. V erify netwo rk c o nnec tiv ity .
Ping from PC-C to PC-A. The ping should be successful.
Ping from PC-A to PC-C. The ping should be successful.
S tep 2. C rea te a n IO S IP S c o nfigu ra tio n dire c to r y in fla s h.
On R1, create a directory in flash using the mkdir command. Name the directory ipsdir.
R1#mkdir ipsdir
Create directory filename [ipsdir]? <Enter>
Created dir flash:ipsdir
S tep 3. C o nfigu re the IP S s igna tu re s to r a ge lo c a tio n.
On R1, configure the IPS signature storage location to be the directory you just
created.
R1(config)#ip ips config location flash:ipsdir
S tep 4. C rea te a n IP S ru le.
On R1, create an IPS rule name using the ip ips name name command in global
configuration mode. Name the IPS rule iosips.
R1(config)# ip ips name iosips
S tep 5. E na ble lo gging.
IOS IPS supports the use of syslog to send event notification. Syslog notification is
enabled by default. If logging console is enabled, you see IPS syslog messages.
Enable syslog if it is not enabled.
R1(config)# ip ips notify log
Use the clock set command from privileged EXEC mode to reset the clock if necessary.
R1# clock set 01:20:00 6 january 2009
Verify that the timestamp service for logging is enabled on the router using the show
run command. Enable the timestamp service if it is not enabled.
R1(config)# service timestamps log datetime msec
Send log messages to the Syslog server at IP address 192.168.1.50.
R1(config)# logging host 192.168.1.50
S tep 6. C o nfigu re IO S IP S to u s e the s igna tu re c a tego r ies .
Retire the all signature category with the retired true command (all signatures within
the signature release). Unretire the IOS_IPS Basic category with the retired false
command.
R1(config)# ip ips signature-category R1(config-ips-category)# category all R1(config-
ips-category-action)# retired true R1(config-ips-category-action)# exit
R1(config-ips-category)# category ios_ips basic R1(config-ips-category-action)# retired
false R1(config-ips-category-action)# exit
R1(config-ips-cateogry)# exit
Do you want to accept these changes? [confirm] <Enter>
S tep 7. A pply the IP S ru le to a n interfa c e.
Apply the IPS rule to an interface with the ip ips name direction command in interface
configuration mode. Apply the rule outbound on the Fa0/0 interface of R1. After you
enable IPS, some log messages will be sent to the console line indicating that the IPS
engines are being initialized.
Note: The direction in means that IPS inspects only traffic going into the interface.
Similarly, out means only traffic going out the interface.
R1(config)# interface fa0/0
R1(config-if)# ip ips iosips out
Task 2: Modify the Signature
S tep 1. C ha nge the ev ent-a c tio n o f a s igna tu re .
Un-retire the echo request signature (signature 2004, subsig ID 0), enable it and change
the signature action to alert, and drop.
R1(config)# ip ips signature-definition
R1(config-sigdef)# signature 2004 0
R1(config-sigdef-sig)# status
R1(config-sigdef-sig-status)# retired false R1(config-sigdef-sig-status)# enabled true
R1(config-sigdef-sig-status)# exit
R1(config-sigdef-sig)# engine
R1(config-sigdef-sig-engine)# event-action produce-alert
R1(config-sigdef-sig-engine)# event-action deny-packet-inline
R1(config-sigdef-sig-engine)# exit
R1(config-sigdef-sig)# exit
R1(config-sigdef)# exit
Do you want to accept these changes? [confirm] <Enter>
S tep 2. U s e s ho w c o mma nds to v erify IP S .
Use the show ip ips all command to see an IPS configuration status summary. To which
interfaces and in which direction is the iosips rule applied? Fa 0/0 outbound.
S tep 3. V er ify tha t IP S is wo rk ing pro perly .
From PC-C, attempt to ping PC-A. Were the pings successful? Why or why not?
The pings should fail. This is because the IPS rule for event-action of an echo request
was set to “deny-packet- inline.
From PC-A, attempt to ping PC-C. Were the pings successful? Why or why not?
The ping should be successful. This is because the IPS rule does not cover echo reply.
When PC-A pings PC- C, PC-C responds with an echo reply.
S tep 4. V iew the S y s lo g mes s a ge s .
Click on the Syslog server. Select the Config tab. In the left navigation menu, select
SYSLOG to view the log file.
S tep 5. C hec k res u lts .
Your completion percentage should be 100%. Click Check Results to see feedback and
verification of which required components have been completed.