searchnewz Home Page About iEntry Article Archive News WebProWorld Forums Jayde iEntry Contact Advertise Downloads iEntry

eBusiness Help
If you're looking to boost online sales like never before, then your search is over.
Unmatched performance - Often 5x higher than other solutions
Become a LinkMo Affiliate!
Start earning the highest CPA payouts in the industry.

WebProWorld Networking Forum

Unable to upgrade PHP
I need to upgrade PHP to 4.3.10 because of the security issues with our current version. When I attempt to install through BASH using the ./configure command that I got from phpinfo();

Slow FTP connection & occasional "time out"
On Friday last week I uploaded a website via ftp for a customer. The connection was fast and I did all the necessary configuring without any problems at all. The site is running perfectly.

A little help with inadvertant shutdown
I am currently working on a HP 742C home PC. The problem is it shuts down either durring startup or minutes after startup. I tried Removing the PCI cards, thinking it was a PCI problem on the motherboard, but to no avail.

Recent Articles

Apache Webserver - A Quick Tutorial for New Admins
Apache is one of the most commonly used web servers out there. If you are running your own cPanel server your websites will actually run on Apache.

Bloggers Hacked
Well, my primary box was cracked by a dipshit going after the recent bug.

Blaster Worm Maker Jailed
Jeffrey Lee Parson, 19, was sentenced to 18 months in U.S. District Court in Seattle for creating and distributing the a variant of the infamous Blaster worm.

Memories of a Cisco Router
It may often seem like nothing more than a sleek metal box on the outside, but the internal memory components of a Cisco router represent where much of the real magic takes place.

Hidden Dangers with Public Wi-Fi
It's becoming a common thing to see people sitting in public places - train stations, airports, the local Starbucks ... with their laptops, doing their email or writing their blogs, or any manner of things that they'd do when in the office or at home.

Google May be the Favored Tool of Hackers in 2005
ZDNet predicts that Google will be increasingly used by hackers, looking to find their way into your computer.


Debug And Show Commands For ISDN

By Chris Bryant

The major reason I recommend getting your hands on real Cisco equipment rather than a simulator is that real Cisco routers give you the chance to practice and learn show and debug commands.

The knowledge you acquire from debugs is invaluable. Frankly, it's this knowledge that puts you above the "average" CCNA who doesn't have that hands-on experience. Watching debugs in action also gives you a head start on the CCNP. Since 90 - 95% of CCNAs go on to pursue the CCNP, it's a great idea to get started with debugs now.

Don't make the mistake of waiting until you're studying for your CCNP and CCIE to start learning debugs and shows. The work you do for the CCNA is the foundation for everything you'll do in the future.

Never, ever, ever practice debugs on a production network. There are debugs that will give you so much information that the router actually becomes overloaded and then locks up. Never practice debugs on a production network.

It's important to know the proper show and debug commands for ISDN for several reasons. First, by watching ISDN in operation, you can see its processes and better understand what's going on. Secondly, it's difficult if not impossible to properly troubleshoot ISDN without knowing the proper show and debug commands. (It's easy to overlook an ISDN authentication error just by looking at the configuration, but running debug ppp negotiation will quickly show you where the problem lies.)

Let's take a look at the ISDN show and debug commands that every CCNA and CCNP should know.

Show ISDN Status

If you only know one ISDN show command, it's got to be this one. Always use this command after configuring your ISDN switch type and any necessary SPIDs. The command will show you the switch type (and will also show you if you did not configure a switch type), and whether the SPIDs you entered are valid:

R1#show isdn status
Global ISDN Switchtype = basic-ni
ISDN BRI0 interface
     dsl 0, interface ISDN Switchtype = basic-ni
   Layer 1 Status:
   Layer 2 Status:
    TEI = 91, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
    TEI = 92, Ces = 2, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
   Spid Status:
    TEI 91, ces = 1, state = 5(init)
     spid1 configured, no LDN, spid1 sent, spid1 valid
     Endpoint ID Info: epsf = 0, usid = 1, tid = 1
    TEI 92, ces = 2, state = 5(init)
     spid2 configured, no LDN, spid2 sent, spid2 valid
     Endpoint ID Info: epsf = 0, usid = 3, tid = 1
   Layer 3 Status:
    0 Active Layer 3 Call(s)
   Activated dsl 0 CCBs = 0
   The Free Channel Mask: 0x80000003

Request Free R-1 Evaluation Kit
for Application and Content Distribution

Once in a while, you'll get this output from show isdn status:

R2#show isdn status
The current ISDN Switchtype = basic-ni1
ISDN BRI0 interface
   Layer 1 Status:
   Layer 2 Status:
    Layer 2 NOT Activated
   Spid Status:
    TEI Not Assigned, ces = 1, state = 3(await establishment)
     spid1 configured, no LDN, spid1 NOT sent, spid1 NOT valid
    TEI Not Assigned, ces = 2, state = 1(terminal down)
     spid2 configured, no LDN, spid2 NOT sent, spid2 NOT valid

Check your running configuration, and if the SPIDs look good, simply close the BRI interface and open it again. Then run show ISDN status again. If you then see "spids are valid", you're ready to proceed. If you still see a message that the spids are invalid, you've most likely mistyped the SPID.

Read the Rest of the Article

About the Author:
Chris Bryant, CCIE™ #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 You're invited to visit our site and check out our CCNA and CCNP courses and study aids. Chris is always glad to hear from Cisco certification candidates at

About NetworkNewz
NetworkNewz editors, writers and contributors focus on both the big picture and the details of networking. At NetworkNewz our goal is to deliver to you The Key To Network Management.

NetworkNewz is brought to you by:

-- NetworkNewz is an iEntry, Inc. publication --
iEntry, Inc. 880 Corporate Drive, Lexington, KY 40503
2005 iEntry, Inc.  All Rights Reserved  Privacy Policy  Legal

archives | advertising info | news headlines | free newsletters | comments/feedback | submit article

The Keys To Network Management Ask Questions in the Networking Forum NetworkNewz News Archives About Us Feedback NetworkNewz Home Page About Article Archive News Downloads WebProWorld Forums Jayde iEntry Advertise Contact