Cisco Certification: Introduction To ISDN, Part III

Configuring PPP PAP Authentication

Now we know how the ISDN link comes up (interesting traffic), and some scenarios that might cause the link to stay up, we need to look at ISDN authentication schemes. The two methods Cisco certification candidates must be familiar with are PAP and CHAP.

Password Authentication Protocol (PAP) sends the username and password over the ISDN link in clear-text. Sending any passwords over any WAN link in clear-text is generally a bad idea, but it???s important to know you have this option.

Regarding both PAP and CHAP, it???s a common misunderstanding that each side must authenticate the other. PAP and CHAP both support bidirectional and unidirectional authentication that is, R1 can authenticate R2 without R2 necessarily authenticating R1. It???s more common to use unidirectional authentication in a lab environment than a production network, but keep in mind that bidirectional authentication is an option, not a requirement.

The configurations of PAP and CHAP do have their similarities. For both, you???ll configure a username/password combination in global configuration mode. Newcomers to ISDN sometimes put the local router name in for the username remember that the remote router name is the username.

The only real advantage of PAP over CHAP comes in the password configuration. Since PAP actually sends the password as a whole over the link, the two routers can send different passwords during authentication. The operation of CHAP requires that both routers use the same password, and we???ll see why in tomorrow???s article.

Under the BRI interface, you???ll enter encapsulation ppp and ppp authentication pap. So far, your authentication scheme looks like this:

username R2 password CCNA

Int bri0

encapsulation ppp

ppp authentication pap

PAP requires an extra command at this point. The ppp pap sent-username command is required under the interface, indicating the username and password this router will be sending to the remote router.

Int bri0

encapsulation ppp

ppp authentication pap

ppp pap sent-username R1 password CISCO

I always encourage CCNA and CCNP candidates to use as many debugs as possible when working in their lab, since these commands show us how things work. For any PPP authentication, always run debug ppp negotiation before sending interesting traffic to trigger the call. Watching exactly how PAP and CHAP work give you a much better understanding of what???s going on ???behind the command???, and makes you a stronger candidate and a stronger networking engineer.

Tomorrow, we???ll take a look at CHAP, and why routers cannot use the same password on both ends of the link.

Keep studying!

About The Author:

Chris Bryant, CCIE (TM) #12933, has been active in the Cisco certification community for years. He worked his way up from the CCNA to the CCIE, and knows what CCNA and CCNP candidates need to know to be effective on the job and in the exam room.

He is the owner of http://www.thebryantadvantage.com, where he teaches CCNA and CCNP courses to small groups of exam candidates, ensuring they each receive the individual attention they deserve. Classes are offered over the Internet and in person in select cities. Chris has custom-written the Study Guide and Lab Workbook used in each course - no third-party training materials or simulators are used. You're invited to visit our site and check out our CCNA and CCNP Courses, Flash Card Books, and to sign up for our weekly newsletter written personally by Chris. Chris is always glad to hear from Cisco certification candidates at http://www.thebryantadvantage.com.

detailed home cleaning Park Ridge ..
In The News:

The Fox News AI Newsletter gives readers the latest AI technology advancements, covering the challenges and opportunities AI presents.
Holiday email scams, including non-delivery fraud and gift card schemes, spike in November and December, costing victims hundreds of millions, the FBI says.
Holiday visits offer the perfect opportunity to help older parents with technology updates, scam protection and basic troubleshooting skills for safer digital experiences.
Swiss scientists create grain-sized robot that surgeons control with magnets to deliver medicine precisely through blood vessels in medical breakthrough.
Researchers exploited WhatsApp's API vulnerability to scrape 3.5 billion phone numbers. Learn how this massive data breach happened and protect yourself.
Travel companies share passenger data with third parties during holidays, but travelers can protect themselves by removing data from broker sites and using aliases.
Xpeng's humanoid robot moves so realistically that crowds believed it was fake, marking a major advancement in robotics technology ahead of 2026 commercial launch.
Researchers discover phishing scam using invisible characters to evade email security, with protection tips including password managers and two-factor authentication.
iPhone and Android users can reduce battery drain and data usage by restricting Background App Refresh to Wi-Fi connections instead of mobile networks.
Scammers nearly stole an Apple account by exploiting the support system with authentic-looking tickets and phone calls, users can protect themselves with safety steps.
FoloToy restored sales of its AI teddy bear Kumma after a weeklong suspension following safety group findings of risky and inappropriate responses to children.
Threat intelligence firm Synthient uncovers one of the largest password exposures ever, prompting immediate security recommendations.
Viral video shared by Elon Musk shows Tesla's Optimus humanoid robots performing tasks from cooking to construction, garnering over 58.5 million views on social media.
Chinese hackers used Anthropic's Claude AI to launch autonomous cyberattacks on 30 organizations worldwide, marking a major shift in cybersecurity threats.
Apple's new Sleep Score feature gives you a rating for your nightly rest quality. Learn how to set it up on your Apple Watch and iPhone today.
Essential phone settings to enable before losing your device, including Find My network, location services and security features for iPhone and Android.
The Fox News AI Newsletter gives readers the latest AI technology advancements, covering the challenges and opportunities AI presents.
Cybersecurity research shows weak passwords remain a major threat, with simple patterns and number sequences putting millions of accounts at risk.
New Android malware BankBot YNRK silences phones, steals banking data and drains crypto wallets automatically. Learn how this advanced threat works.
FDA approves first human trial for Paradromics' brain-computer interface that could restore speech for paralyzed patients through neural technology.
New phishing platform QRR targets Microsoft 365 users across 1,000 domains in 90 countries. Learn how to spot fake login pages and protect your accounts.
OpenTable now uses AI to track your dining habits and share insights with restaurants. Learn what data they collect and how to protect your privacy.
Google's discontinued Nest thermostats still secretly upload home data to company servers despite losing smart features, raising serious privacy concerns.
New Android malware NGate steals NFC payment codes in real-time, allowing criminals to withdraw cash from ATMs without your card. Learn protection tips.
DoorDash confirms data breach exposing customer names, emails, addresses after social engineering attack. Learn how to protect yourself from scams.

Corporate ERP: Standard vs. Rich functionality ? Microsoft Great Plains

Traditionally we were considering functionally rich systems, such as SAP,... Read More

Mapping Software: Putting Data Visualization on the Map

Mapping Software Improves Data VisualizationFrom the outset, it is important... Read More

Microsoft CRM ? Consulting in the Post-Recession Time

New post-recession era has new features, which didn't exist in... Read More

Start Developing Your Own Software

Learning how to program software seems like a daunting task... Read More

Protect Your Most Vital Business Asset with Security Software

Homeland security, airport security, Internet security ??" these days we???re... Read More

Microsoft Navision Customization Upgrade ? Tips For Programmer/IT Specialist

Currently Microsoft Business Solutions is on the way of creating... Read More

Screenshots Vista Windows

Features Additionally, Vista will include many other new features.Aero Vista... Read More

Microsoft Great Plains as ERP and Microsoft CRM as CRM

If you have Microsoft Great Plains and support it for... Read More

Microsoft Great Plains Furniture & Fixtures ? Implementation & Customization Highlights

Microsoft Great Plains, former Great Plains Software Dynamics / eEnterprise... Read More

Microsoft Great Plains Inventory Control ? Overview For Consultant

Microsoft Business Solutions Great Plains is marketed for mid-size companies... Read More

Microsoft Great Plains eCommerce: overview for developer

Microsoft Business Solutions Great Plains was designed back in the... Read More

Microsoft Great Plains, Navision, Axapta ? Selection Considerations

During the years of our consulting practice, which comes back... Read More

Microsoft Great Plains Accounting/ERP Implementation ? Finance Industry Customization Example

Microsoft Business Solutions Great Plains is very generic accounting application... Read More

MySQL for Beginners ? How to Create a MySQL Database

Whether you are an experienced web programmer or a complete... Read More

IBM Lotus Domino or Microsoft Exchange?

IBM Lotus Domino or Microsoft Exchange?The severe competition continues for... Read More

Free Microsoft Word Online Training Tutorial Resources

Microsoft Word is one of the most popular office applications... Read More

Integrating Microsoft Great Plains Accounting/ERP: RMS, CRM, eCommerce, Lotus Domino ? overview

Microsoft Business Solutions Great Plains has substantial market share among... Read More

Navision Attain C/ODBC Crystal Report ? Customization Example

Microsoft Business Solutions Navision is main ERP application for European,... Read More

Seven Reasons Why a Hosted Inventory Management Solution Might Be Right For Your Organization

Upgrading. Downtime. Maintenance. Hardware obsolescence. Implementation issues. The litany of... Read More

Defining OLAP Solutions and Data Warehouse design

This tutorial covers OLAP solutions used by Data warehouses and... Read More

Benefits of Integrating Online Chat Software with CRM

Customer Relationship Management (CRM) is a strategy and processes used... Read More

C++ Function Templates

C++ Function templates are those functions which can handle different... Read More

Destination: Desktop for Google

First we had the original Google search that evolved into... Read More

Change Your Word Docs in Record Time!

Anyone who has ever used Microsoft Word knows that it... Read More

How to Build a Basic CSS Layout

Designing without tables by using CSS layouts is fast becoming... Read More

express cleaning service Des Plaines ..