Home > Articles > Cisco Certification > CCIE > CCIE Security Practice Labs

CCIE Security Practice Labs

  • Sample Chapter is provided courtesy of Cisco Press.
  • Date: Mar 26, 2004.

Section 5.0: IPSec/GRE Configuration

5.1: IPSec

5.1.1: IPSec LAN-to-LAN Using Preshared

  1. Configure a LAN-to-LAN IPSec between the PIX and R4. The key is the interesting traffic for IPSec—the IPSec access list, which should be for UDP port 45000, the postoffice protocol communication between the IDS and Director. You can also configure an access list for UDP traffic from host to host—10.50.13.82 to 10.50.31.60.

5.1.2: Advanced IPSec LAN-to-LAN

  1. Configure GRE traffic in section 5.2. IPSec access list should be host-to-host and use tunnel mode. Configure ISAKMP keepalive to check the connectivity. If the peer does not respond, phase1 SA will go down and this will also take down the phase 2 SAs.

  2. Also remember to configure no ip route-cache on all GRE tunnels and physical interfaces where crypto map is applied.

5.2: GRE

  1. This is a tricky one. Configure GRE between R3 and R6. You need to configure static translation on PIX for loopback2 to the same address for GRE tunnel on R3 to peer as the GRE destination.

  2. Furthermore, modify the outside access list on PIX to allow ESP and UDP/500 from host 133.133.133.133 to 166.166.166.166. You do not need to allow GRE since the packets will be encrypted as per section 5.1.2:

    3. access-list outside permit esp host 133.133.133.133 host 166.166.166.166 (hitcnt=79166)
access-list outside permit udp host 133.133.133.133 host 166.166.166.166 eq isakmp (hitcnt=99)
static (inside,outside) 166.166.166.166 166.166.166.166

  3. Redistribute OSPF into EIGRP 100 with a route map to match only loopbacks in area30. The example that follows is for the redistribution configuration on R3:

    4. router eigrp 100
 redistribute ospf 110 route-map o2e.
!
access-list 2 permit 30.30.1.0
access-list 2 permit 30.30.2.0
access-list 2 permit 30.30.3.0
access-list 2 permit 30.30.4.0
access-list 2 permit 30.30.5.0
access-list 2 permit 30.30.6.0
!
route-map o2e permit 10
 match ip address 2

    We are not done yet.

    Now, if you do a show ip route on R6, you will see that it is learning all the routes via the GRE tunnel interface as expected. See the routing table on R6:

    r6#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
  D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
  N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
  E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
   i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
  * - candidate default, U - per-user static route, o - ODR
  P - periodic downloaded static route

Gateway of last resort is 10.10.6.1 to network 0.0.0.0

D EX 30.30.1.0 [170/297270016] via 36.36.36.3, 00:13:47, Tunnel63
D EX 30.30.2.0 [170/297270016] via 36.36.36.3, 00:13:47, Tunnel63
D EX 30.30.3.0 [170/297270016] via 36.36.36.3, 00:13:47, Tunnel63
D EX 30.30.4.0 [170/297270016] via 36.36.36.3, 00:13:47, Tunnel63
D EX 30.30.5.0 [170/297270016] via 36.36.36.3, 00:13:47, Tunnel63
D EX 30.30.6.0 [170/297270016] via 36.36.36.3, 00:13:47, Tunnel63
R* 0.0.0.0/0 [120/1] via 10.10.6.1, 00:00:16, Ethernet0/1

    The question requires pinging the even networks via the tunnel and odd networks via the PIX. In doing so, it is allowed to use an ACL with one line only.

    The solution is "policy routing." You need to create a policy route to match the odd networks and set the next hop to the PIX inside interface—that is, 10.10.6.1—and apply it in global mode, as packets will originate from R6 when testing:

    ip local policy route-map next-hop
!
access-list 102 permit ip any 30.30.1.0 0.0.254.255
!
route-map next-hop permit 10
 match ip address 102
 set ip next-hop 10.10.6.1

    The way to confirm if it is working is to turn on debug icmp trace on PIX, and ping the odd networks. You will see the packets flowing through, but when you ping even networks, it won't show, as they will be traversing as GRE/IPSec packets and not ICMP traffic. The following example demonstrates this procedure.

    pix# debug icmp trace
ICMP trace on
Warning: this may cause problems on busy networks

r6#ping 30.30.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 30.30.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 104/179/200 ms

r6#ping 30.30.2.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 30.30.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 8/8/8 ms

pix# debug icmp trace
ICMP trace on
Warning: this may cause problems on busy networks
pix# 190: Outbound ICMP echo request (len 72 id 58378 seq 1947) 36.36.36.6 > 10.50.31.1 >30.30.1.1
191: Inbound ICMP echo reply (len 72 id 17920 seq 1947) 30.30.1.1 > 10.50.31.1 > 36.36.36.6
192: Outbound ICMP echo request (len 72 id 58634 seq 1947) 36.36.36.6 > 10.50.31.1 > 30.30.1.1
193: Inbound ICMP echo reply (len 72 id 18176 seq 1947) 30.30.1.1 > 10.50.31.1 > 36.36.36.6
194: Outbound ICMP echo request (len 72 id 58890 seq 1947) 36.36.36.6 > 10.50.31.1 > 30.30.1.1
195: Inbound ICMP echo reply (len 72 id 18432 seq 1947) 30.30.1.1 > 10.50.31.1 > 36.36.36.6
196: Outbound ICMP echo request (len 72 id 59146 seq 1947) 36.36.36.6 > 10.50.31.1 > 30.30.1.1
197: Inbound ICMP echo reply (len 72 id 18688 seq 1947) 30.30.1.1 > 10.50.31.1 > 36.36.36.6
198: Outbound ICMP echo request (len 72 id 59402 seq 1947) 36.36.36.6 > 10.50.31.1 > 30.30.1.1
199: Inbound ICMP echo reply (len 72 id 18944 seq 1947) 30.30.1.1 > 10.50.31.1 > 36.36.36.6

    As you can see, that ping works for both the odd and even networks from R6, but ICMP packets are only seen when pinging the odd network, not the even network.

    Note that the return echo-reply packets are sent back to the 36.36.36.6 IP address, which is the tunnel IP on R6.

    You need to create a static route on PIX for this network, or you will notice that the odd network pings are unsuccessful.

20. Section 6.0: IOS Firewall Configuration | Next Section Previous Section

Cisco Press Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Cisco Press and its family of brands. I can unsubscribe at any time.

Overview

Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Cisco Press products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@ciscopress.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security

Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children

This site is not directed to children under the age of 13.

Marketing

Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out

Users can always make an informed choice as to whether they should proceed with certain services offered by Cisco Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.ciscopress.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links

This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020