Cisco CCNA / CCNP Exam Tutorial: Testing ISDN One-way links Devoid of Pings
To receive your Cisco CCNA and CCNP certifications, you’ve acquired to learn ISDN – and Irrespective of what a number of people say, there’s continue to loads of ISDN on the market that needs to be supported. And In relation to troubleshooting ISDN, there’s a whole lot to take a look at. Is the right ISDN switchtype configured? Will be the dialer map statements proper? How about the dialer-group and dialer-record instructions? Which’s just the start.
I constantly say that every one troubleshooting commences at Layer 1, the Actual physical layer from the OSI product. The usual way of troubleshooting ISDN is sending pings throughout the website link, although the relationship is often analyzed without the need of using pings and even right before assigning IP addresses for the BRI interfaces!
It’s a smart idea to place these take a look at calls in advance of configuring the interfaces – like that, you are aware of you’ve acquired a legitimate link just before beginning the configuration (and there’s a lot of config to associate with ISDN!)
To position a take a look at call with out working with pings, utilize the isdn call interface command.
R1#isdn contact interface bri0 8358662
R1#
03:fifty four:43: BR0 DDR: Attempting to dial http://query.nytimes.com/search/sitesearch/?action=click&contentCollection®ion=TopBar&WT.nav=searchWidget&module=SearchSubmit&pgtype=Homepage#/먹튀검증 8358662
03:fifty four:forty three: %Url-three-UPDOWN: 먹튀검증 Interface BRI0:one, altered condition to up
03:fifty four:forty four: BR0:1 DDR: dialer protocol up
03:fifty four:45: %LINEPROTO-five-UPDOWN: Line protocol on Interface BRI0:one, altered state to up
03:54:forty nine: %ISDN-6-CONNECT: Interface BRI0:1 has become connected to 8358662 R2
To tear the exam contact down the right way, use isdn disconnect interface. IOS Assistance shows the options with this particular command.
R1#isdn disconnect interface bri 0 ?
all Disconnect the info call(s) on all b channels
b1 Disconnect the information call on b1 channel
b2 Disconnect the data simply call on b2 channel
R1#isdn disconnect interface bri 0 all
03:58:36: BR0:one DDR: disconnecting simply call
03:58:36: BR0:two DDR: disconnecting contact
03:58:36: %ISDN-6-DISCONNECT: Interface BRI0:1 disconnected from 8358662
R2, phone lasted 20 seconds
03:fifty eight:36: %Url-3-UPDOWN: Interface BRI0:one, modified point out to down
03:58:37: %LINEPROTO-five-UPDOWN: Line protocol on Interface BRI0:one, transformed point out to down
I say “accurately” as the one thing you don’t want to do to finish an ISDN contact, examination or in any other case, is simply shut the interface. Telcos don’t like it, and ISDN lab units like it even significantly less. Often let the d-channel do its function and tear the call down within an orderly style – don’t just Slash it off by shutting the interface down.