CCNA exam good results relies upon mostly on noticing the main points, which is especially true of configurations involving immediately connected serial interfaces. And naturally, it’s not sufficient to note these facts – you’ve obtained to grasp what to do about them!
A Cisco router is really a DTE by http://www.bbc.co.uk/search?q=먹튀검증 default, but specifically connecting two DTEs with a DCE/DTE cable is not really more than enough. In the subsequent case in point, R1 and R3 are immediately related at their Serial1 interfaces. The road goes up briefly just after currently being opened, but the line protocol goes down after about thirty seconds.
R3(config-if)#int s1
R3(config-if)#ip deal with 172.12.thirteen.three 255.255.255.0
R3(config-if)#no shutdown
2d18h: %Connection-3-UPDOWN: Interface Serial1, transformed point out to up
2d18h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, modified condition to up
R3(config-if)#
2d18h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, modified point out to down
The problem is that one of several routers really should act given that the DCE to ensure that the line protocol to come up and stay up. If this ended up your CCNA / CCNP house lab, you may just go more than and think about the DTE/DCE cable to see which router had the DCE conclusion of your cable attached. In this instance, nevertheless, we don’t have Bodily usage of the routers. How can we notify which router has the DCE close of the cable hooked up?
R3#clearly show controller serial one
HD unit one, idb = 0x1C44E8, driver construction at 0x1CBAC8
buffer dimensions 1524 High definition device 1, V.35 DCE cable
The exhibit controller command offers us this details. (There’s quite a bit much more output that this with this command, but it surely’s unimportant for our reasons.) The router with the DCE conclusion with the cable requirements to produce a clock amount into the DTE, and we’ll just do that While using the interface-degree clockrate command.
R3#conf t
Enter configuration commands, a person for every line. Conclusion with CNTL/Z.
R3(config)#int serial1
R3(config-if)#clockrate 56000
In just some seconds, the line protocol goes up and stays up.
When troubleshooting a connection, generally run present interface first. If the thing is The mix proven underneath, the relationship is physically high-quality but logically down. That’s commonly the results of a required keepalive not staying existing. With Frame Relay, it’s probably 토토검증 an LMI difficulty, but with directly linked serial interfaces The problem is more than likely the DCE conclusion in the relationship not supplying clockrate.
R3#demonstrate interface serial 1
Serial1 is up, line protocol is down
Troubleshooting is a major Component of The task, and it’s an enormous part of the Cisco CCNA and CCNP plans in addition. Know your present and debug commands and also you’re on the method to passing the CCNA!