Configuring a Zone-Based Policy Firewall
发表时间:2010-8-12 评论:0 点击 3,884+
Addressing Table
Device | Interface | IP Address | Subnet Mask | Default Gateway |
R1 | Fa0/1 | 192.168.1.1 | 255.255.255.0 | N/A |
S0/0/0 | 10.1.1.1 | 255.255.255.252 | N/A | |
R2 | S0/0/0 | 10.1.1.2 | 255.255.255.252 | N/A |
S0/0/1 | 10.2.2.2 | 255.255.255.252 | N/A | |
R3 | Fa0/1 | 192.168.3.1 | 255.255.255.0 | N/A |
S0/0/1 | 10.2.2.1 | 255.255.255.252 | N/A | |
PC-A | NIC | 192.168.1.3 | 255.255.255.0 | 192.168.1.1 |
PC-C | NIC | 192.168.3.3 | 255.255.255.0 | 192.168.3.1 |
Learning Objectives
Verify connectivity among devices before firewall configuration.
Configure a zone-based policy (ZPF) firewall on router R3
Verify ZPF firewall functionality using ping, Telnet and a web browser.
Introduction
Zone-based policy (ZPF) firewalls are the latest development in the evolution of Cisco
firewall technologies. In this activity, you configure a basic ZPF on an edge router R3
that allows internal hosts access to external resources and blocks external hosts from
accessing internal resources. You then verify firewall functionality from internal and
external hosts.
The routers have been pre-configured with the following:
Console password: ciscoconpa55
Password for vty lines: ciscovtyp
Enable password: ciscoenpa55
Host names and IP addressing
Static routing
Task 1: Verify Basic Network Connectivity
Verify network connectivity prior to configuring the zone-based policy firewall.
S tep 1. F ro m the P C -A c o mma nd pro mpt, ping P C -C a t 192. 168. 3.3.
S tep 2. F ro m the P C -C c o mma nd pro mpt, T elnet to the R o u ter R 2 S 0/0/1 inte
rfa c e a t 10. 2. 2. 2. E x it the
T elnet s es s io n.
S tep 3. F ro m P C -C , o pen a web bro ws er to the P C -A s erv er .
Click the Desktop tab and click the Web Browser application. Enter the PC-A IP address
192.168.1.3 as the
URL. The Packet Tracer 5.x welcome page from the web server should be displayed. Close
the browser on PC-C.
Task 2: Create the Firewall Zones on Router R3
Note: For all configuration tasks, be sure to use the exact names as specified.
S tep 1. C rea te a n inte rna l z o ne.
Use the zone security command to create a zone named IN-ZONE.
R3(config)# zone security IN-ZONE
S tep 2. S tep 2. C re a te a n ex te rna l z o ne.
Use the zone security command to create a zone named OUT-ZONE.
R3(config-sec-zone)# zone security OUT-ZONE
R3(config-sec-zone)# exit
Task 3: Define a Traffic Class and Access List
S tep 1. C reate an A C L tha t d efine s interna l tra ffic .
Use the access-list command to create extended ACL 101 to permit all IP protocols from
the 192.168.3.0/24
source network to any destination.
R3(config)# access-list 101 permit ip 192.168.3.0 0.0.0.255 any
S tep 2. C rea te a c la s s ma p refer e nc ing the interna l tra ffic A C L .
Use the class map type inspect command with the match-all option to create a class map
named IN-NET- CLASS-MAP. Use the match access-group command to match ACL 101.
R3(config)# class-map type inspect match-all IN-NET-CLASS-MAP
R3(config-cmap)# match access-group 101
R3(config-cmap)# exit
Note: Although not supported in this Packet Tracer exercise, individual protocols (HTTP,
FTP, etc.) can be specific to be matched using the match-any option in order to provide
more precise control over what type of traffic is inspected.
Task 4: Specify Firewall Policies
S tep 1. C rea te a po lic y ma p to de termine wha t to do with ma tc hed tra ffic .
Use the policy-map type inspect command and create a policy map named IN-2-OUT-PMAP.
R3(config)# policy-map type inspect IN-2-OUT-PMAP
S tep 2. S pec ify a c la s s ty pe o f in s pec t a nd refer enc e c la s s ma p IN -NE
T -C L AS S -M A P .
R3(config-pmap)# class type inspect IN-NET-CLASS-MAP
S tep 3. S pec ify the a c tio n o f in s pec t fo r this po lic y m a p
The use of the inspect command invokes context-based access control (other options
include pass and drop).
R3(config-pmap-c)# inspect
%No specific protocol configured in class IN-NET-CLASS-MAP for inspection. All protocols
will be inspected.
Issue the exit command twice to leave config-pmap-c mode and return to config mode.
R3(config-pmap-c)# exit
R3(config-pmap)# exit
Task 5: Apply Firewall Policies
S tep 1. C reate a pa ir o f z o nes .
Using the zone-pair security command, create a zone pair named IN-2-OUT-ZPAIR. Specify
the source and destination zones that were created in Task 1.
R3(config)# zone-pair security IN-2-OUT-ZPAIR source IN-ZONE destination
OUT-ZONE
S tep 2. S pec ify the po lic y ma p fo r ha ndling the tr a ffic between the two z o
nes .
Attach a policy-map and its associated actions to the zone pair using the service-policy
type inspect
command and reference the policy map previously created, IN-2-OUT-PMAP.
R3(config-sec-zone-pair)# service-policy type inspect IN-2-OUT-PMAP
R3(config-sec-zone-pair)# exit
R3(config)#
S tep 3. A s s ign inte rfa c e s to the a ppro pria te s ec u rity z o nes .
Use the zone-member security command in interface config mode to assign Fa0/1 to IN-ZONE
and S0/0/1 to
OUT-ZONE.
R3(config)# interface fa0/1
R3(config-if)# zone-member security IN-ZONE
R3(config-if)# exit
R3(config)# interface s0/0/1
R3(config-if)# zone-member security OUT-ZONE
R3(config-if)# exit
S tep 4. C o py the ru nning c o nfig to the s ta rtu p c o nfig.
Task 6: Test Firewall Functionality from IN-ZONE to OUT-ZONE
Verify that internal hosts can still access external resources after configuring the
zone-based policy firewall.
S tep 1. F ro m interna l P C -C , ping the ex tern a l PC -A s e rv er.
From the PC-C Command Prompt, ping PC-A at 192.168.1.3. The ping should succeed.
S tep 2. F ro m interna l P C -C , T elnet to the ro u ter R 2 S 0/0/1 interfa c e.
From the PC-C Command Prompt, telnet to R2 at 10.2.2.2 and provide the vty password
ciscovtypa55. The telnet should succeed. While the Telnet session is active, issue the
command show policy-map type inspect zone-pair sessions on R3 to view established
sessions.
R3# show policy-map type inspect zone-pair sessions
Zone-pair: IN-ZONE-OUT-ZONE
Service-policy inspect : IN-2-OUT-PMAP
Class-map: IN-NET-CLASS-MAP (match-all) Match: access-group 101
Inspect
Established Sessions
Session 139644744 (192.168.3.3:1025)=>(10.2.2.2:23) telnet:tcp
SIS_OPEN
Created 00:00:02, Last heard 00:00:00
Bytes sent (initiator:responder) [0:0]
What is the source IP address and port number? 192.168.3.3:1025 (port 1025 is random)
What is the destination IP address and port number? 10.2.2.2:23 (Telnet = port 23)
S tep 3. F ro m P C -C , ex it the T elne t s es s io n o n R 2 a nd c lo s e the C o
mma nd P ro mpt window .
S tep 4. F ro m interna l PC -C , o pen a web bro ws er to the P C -A s erv e r web pa
ge.
Enter the server IP address 192.168.1.3 in the browser URL field and click Go. The HTTP
session should succeed. While the HTTP session is active, issue the command show
policy-map type inspect zone-pair sessions on R3 to view established sessions.
Note: If the HTTP session times out before you execute the command on R3, you will have
to click the Go
button on PC-C to generate a session between PC-C and PC-A.
R3# show policy-map type inspect zone-pair sessions
Zone-pair: IN-ZONE-OUT-ZONE
Service-policy inspect : IN-2-OUT-PMAP
Class-map: IN-NET-CLASS-MAP (match-all) Match: access-group 101
Inspect
Established Sessions
Session 139142400 (192.168.3.3:1027)=>(192.168.1.3:80)
http:tcp SIS_OPEN
Created 00:00:02, Last heard 00:00:00
Bytes sent (initiator:responder) [0:0]
What is the source IP address and port number? 192.168.3.3:1027 (port 1027 is random)
What is the destination IP address and port number? 192.168.1.3:80 (HTTP web = port 80)
S tep 5. C lo s e the B ro ws er o n P C -C.
Task 7: Test Firewall Functionality from OUT-ZONE to IN-ZONE
Verify that external hosts CANNOT access internal resources after configuring the zone-
based policy firewall.
S tep 1. F ro m the P C -A s e rv er c o mma nd pro mpt, ping P C -C .
From the PC-A Command Prompt, ping PC-C at 192.168.3.3. The ping should fail.
S tep 2. F ro m ro u ter R 2, ping P C -C.
From R2, ping PC-C at 192.168.3.3. The ping should fail.
S tep 3. 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.