Cisco CCNA / CCNP Exam Tutorial: Testing ISDN Hyperlinks Without having Pings

Izvor: KiWi

To earn your Cisco CCNA and CCNP certifications, you have got to master ISDN - and regardless of what some people say, there's nevertheless a lot of ISDN out there that wants to be supported. And when it comes to troubleshooting ISDN, there's a lot to look at find out more . Is the appropriate ISDN switchtype configured? Are the dialer map statements right? What about the dialer-group and dialer-list commands? And that's just the start off.

I constantly say that all troubleshooting begins at Layer 1, the Physical layer of the OSI model. The usual technique of troubleshooting ISDN is sending pings across the link, but the connection can be tested with out employing pings or even before assigning IP addresses to the BRI interfaces!

It's a excellent concept to place these test calls ahead of configuring the interfaces - that way, you know you have got a valid connection ahead of starting the configuration (and there is a lot of config to go along with ISDN!)

To spot a test call with out employing pings, use the isdn contact interface command.

R1#isdn get in touch with interface bri0 8358662

R1#

03:54:43: BR0 DDR: Attempting to dial 8358662

03:54:43: %Hyperlink-three-UPDOWN: Interface BRI0:1, changed state to up

03:54:44: BR0:1 DDR: dialer protocol up

03:54:45: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0:1, changed state to up

03:54:49: %ISDN-six-CONNECT: Interface BRI0:1 is now connected to 8358662 R2

To tear the test call down properly, use isdn disconnect interface visit microsoft group policy . IOS Assist displays the choices with this command.

R1#isdn disconnect interface bri  ?

all Disconnect the information get in touch with(s) on all b channels

b1 Disconnect the data contact on b1 channel

b2 Disconnect the information contact on b2 channel

R1#isdn disconnect interface bri all

03:58:36: BR0:1 DDR: disconnecting call

03:58:36: BR0:2 DDR: disconnecting get in touch with

03:58:36: %ISDN-six-DISCONNECT: Interface BRI0:1 disconnected from 8358662

R2, get in touch with lasted 20 seconds

03:58:36: %Link-3-UPDOWN: Interface BRI0:1, changed state to down

03:58:36: BR0:1 DDR: disconnecting get in touch with

03:58:37: %LINEPROTO-five-UPDOWN: Line protocol on Interface BRI0:1, changed state to down

I say "correctly" since the 1 point you never want to do to finish an ISDN call, test or otherwise, is just shut the interface. Telcos never like it, and ISDN lab devices like it even less site link . Often let the d-channel do its operate and tear the call down in an orderly fashion - do not just reduce it off by shutting the interface down.SDM Software, Inc.
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