Welcome! It's Sunday, July 20, and here are the answers to yesterday's free Cisco certification exam training questions. All of yesterday's questions were short answer.

CCNA Certification:

You've opened a serial interface on a Cisco router, and you see the following:

R1#show interface serial0
Serial0 is down, line protocol is down

What should you check on the local end of the connection?

Answer: Always check the physical connection first. We know the interface is logically open, since we don't see Serial0 is administratively down. When you just see down for the physical interface state, the cable may simply be loose.


CCENT Certification:

You just created a database on a router with the username/password command. You want the contents of this database to be used to authentication incoming Telnet connections. What command is required on the VTY lines to do so?

Answer: The login local command forces the router to use the local database.


CCNA Security Certification / CCNP ISCW Exam:

You're using the Authentication Proxy. Where can you store the user-specific security profiles?

Answer: The profiles can be downloaded from a TACACS+ or RADIUS server.


CCNP Certification / BSCI Exam:

What's the default value for the variance command?

Answer: 1. ( It's not zero!)


CCNP Certification / BCMSN Exam:

What's the basic purpose of UDLD?

Answer: There are situations where a physical layer issue disables data transfer in one direction, but not the other.

UniDirectional Link Detection (UDLD) detects these unidirectional links by transmitting a UDLD frame across the link. If a UDLD frame is received in return, that indicates a bidirectional link, and all is well.

If a UDLD frame is not received in return, the link is considered unidirectional. It's really like a Layer 2 ping. If the UDLD "echo" is seen, there's bidirectional communication; if the "echo" is not seen, there isn't!


CCNP / ONT Exam:

Is there a default QoS model? If so, what is it?

Answer: If you have no QoS scheme in place, you're still using a QoS model - best-effort.


Answers posted right here on Sunday, July 19! Be sure to read today's other blog posts for exciting news about the new CCNA certifications, especially the CCNA Security certification!

To your success,

Chris Bryant
CCIE #12933
http://www.thebryantadvantage.com/