Home > Articles > Certification > Cisco Certification > CCNP Security / CCSP

Routing Protocol Authentication Concepts and Configuration

  • Jul 13, 2011
One of the ways that a network can be exploited is by an attacker gaining access to a directly connected network line and directly influencing the route traffic takes to reach a destination. For example, a route for traffic could be changed to route through a device that is able to capture the traffic and resend it leaving few footprints of attack. One of the methods that can be used to prevent these types of attack is the use of routing protocol authentication. This article takes a look at the available routing protocol authentication options for the most often used routing protocols: EIGRP, OSPF, RIP and BGP.
Like this article? We recommend

Like this article? We recommend

CCNP Security Secure 642-637 Official Cert GuideCCNP Security Secure 642-637 Official Cert Guide

Learn More Buy

Like this article? We recommend

Like this article? We recommend

CCNP Security Secure 642-637 Official Cert GuideCCNP Security Secure 642-637 Official Cert Guide

Learn More Buy

There are two general ways that authentication is implemented by most routing protocols: using a routing protocol centric solution that configures the passwords or keys to use within the routing protocol configuration, or by using a broader solution that utilizes separately configured keys that are able to be used by multiple routing protocols. Both OSPF and BGP use the prior of these methods and configure the specific authentication type and passwords/keys within their specific respective configurations. RIP and EIGRP utilize the former of these methods by utilizing a separate authentication key mechanism that is configured and then utilized for either RIP or EIGRP.

Keep in mind that these authentication solutions do not encrypt the information exchanged between the devices, but simply verifies that the identity of these devices.

Key Chains

The idea behind a key chain is rather simple as it simply replicates an electronic version of a key chain, a concept that most people are familiar with. The key chain functionality provides a mechanism for storing a number of different electronic keys, the key string value that is associated with a specific key and the lifetime that the key is valid. Any one of these configured keys can then be used by RIP or EIGRP for authentication.

Routing Protocol Authentication Configuration

As there are two different ways to configure routing protocol authentication; this article will review OSPF and BGP first as they require individualized configuration. The configuration of key chains and how they are used by RIP and EIGRP will then be covered.

OSPF Authentication

The configuration of OSPF requires a couple of different commands; which commands are used is determined by the type of authentication and method of authentication exchange. OSPF supports two different types of authentication that can be configured: authentication limited to a specific interface, or authentication configured over an entire OSPF area. Regardless of which of these options is selected there are also two different methods of authentication exchange that can be configured for each, these include: cleartext simple exchange, or MD5 exchange. When using MD5 the password/key that is configured is not sent between the exchanging devices, instead a hash is calculated and sent; this hash is then verified by the remote device to ensure identity.

The commands are required to setup OSPF interface (network) authentication is shown in Table 1.

Step 1

Enter privileged mode.

router>enable

Step 2

Enter global configuration mode.

router#configure terminal

Step 3

Enter interface configuration mode.

router(config)#interface interface-type interface-slot

Step 4

Configure OSPF (network) authentication.

To configure MD5 authentication use the message-digest keyword.

router(config-if)#ip ospf authentication [message-digest]

Step 5

Configure the OSPF Authentication key.

router(config-if)#ip ospf authentication-key key

or

router(config-if)#ip ospf message-digest-key key-id md5 key

Step 6

Exit configuration mode.

router(config-if)#end

The commands that are required to setup OSPF area authentication are shown in Table 2.

Step 1

Enter privileged mode.

router>enable

Step 2

Enter global configuration mode.

router#configure terminal

Step 3

Enter router configuration mode.

router(config)#router ospf process-id

Step 4

Configure OSPF area authentication.

To configure MD5 authentication use the message-digest keyword.

router(config-router)#area area-id authentication [message-digest]

Step 5

Enter interface configuration mode.

router(config-router)#interface interface-type interface-slot

Step 6

Configure the OSPF Authentication key.

router(config-if)#ip ospf authentication-key key

or

router(config-if)#ip ospf message-digest-key key-id md5 key

Step 7

Exit configuration mode.

router(config-line)#end

BGP Authentication

The configuration of authentication with BGP is very simple as it requires only a single configuration command. Unlike OSPF, BGP only supports the use of MD5 authentication.

The commands that are required to setup BGP authentication are shown in Table 3.

Step 1

Enter privileged mode.

router>enable

Step 2

Enter global configuration mode.

router#configure terminal

Step 3

Enter router configuration mode.

router(config)#router bgp autonomous-system

Step 4

Configure BGP authentication.

router(config-router)#neighbor {ip-address | peer-group-name} password key

Step 5

Exit configuration mode.

router(config-router)#end

RIP and EIGRP Authentication

As discussed above, the configuration of both RIP and EIGRP utilize key chains for their authentication configuration. This section will describe the process of setting up a key chain for use with RIP and EIGRP then cover the configuration of the specific authentication configuration required by each protocol.

Key Chain Configuration

The key chain configuration provides the ability to setup multiple keys that can be used by the supporting features. This includes the ability to have keys that potentially overlap in the time that they are valid. Keys can also be configured with specific transmit (send) and receive (accept) lifetimes that provide the ability to have keys automatically change at a predetermined time. The configuration required to setup a key chain are shown in Table 4.

Step 1

Enter privileged mode.

router>enable

Step 2

Enter global configuration mode.

router#configure terminal

Step 3

Create a key chain and enter key chain configuration mode.

router(config)#key chain name-of-key-chain

Step 4

Create a key and enter key configuration mode.

router(config-keychain)#key key-id

Step 5

Configure a secret key.

router(config-keychain-key)#key-string key-string

Step 6

Configure the receive key lifetime.

router(config-keychain-key)#accept-lifetime start-time {infinite | end-time | duration seconds}

Step 7

Configure the transmit key lifetime.

router(config-keychain-key)#send-lifetime start-time {infinite | end-time | duration seconds}

Step 8

Exit configuration mode.

router(config-keychain-key)#end
EIGRP Authentication Configuration

Once a key chain has been configured, the authentication for EIGRP neighbors is enabled on each interface that is connected to an authenticating neighbor. The configuration required to setup EIGRP authentication is shown in Table 5.

Step 1

Enter privileged mode.

router>enable

Step 2

Enter global configuration mode.

router#configure terminal

Step 3

Enter interface configuration mode.

router(config)#interface interface-type interface-slot

Step 4

Configure the use of a specific key chain key for authentication.

router(config-if)#ip authentication key-chain eigrp as-number key-chain-name

Step 5

Configure the use of EIGRP authentication.

router(config-if)#ip authentication mode eigrp as-number md5

Step 6

Exit configuration mode.

router(config-if)#end
RIP Authentication Configuration

As with EIGRP, once a key chain has configured the authentication, RIP authentication can be configured. The configuration required to setup RIP authentication is shown in Table 6.

Step 1

Enter privileged mode.

router>enable

Step 2

Enter global configuration mode.

router#configure terminal

Step 3

Enter interface configuration mode.

router(config)#interface interface-type interface-slot

Step 4

Configure the use of a specific key chain key for authentication.

router(config-if)#ip rip authentication key-chain key-chain-name

Step 5

Configure the use of RIP authentication.

Unlike EIGRP, RIP supports a clear text authentication option using the text keyword, this mode is not recommended.

router(config-if)#ip rip authentication mode {text | md5}

Step 6

Exit configuration mode.

router(config-if)#end

Summary

The integrity of routing information inside a network is of the utmost importance as it can influence how traffic reaches specific destinations. Configuring the use of routing protocol authentication is an easy option that ensures that the device on the other side of a connection is who they say they are. Hopefully, the information contained within this article has been able to introduce the possibilities and how they can be configured.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT 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 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@informit.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 InformIT. 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.informit.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