CCNA exam accomplishment relies upon mostly on noticing the details, which is especially true of configurations involving straight related serial interfaces. And naturally, it’s not ample to notice these facts – you’ve obtained to find out how to proceed about them!
A Cisco router is really a DTE by default, but specifically connecting two DTEs using a DCE/DTE cable is not really adequate. In the following case in point, R1 and R3 are instantly connected at their Serial1 interfaces. The road goes up briefly following becoming opened, but the line protocol goes down soon after about 30 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-three-UPDOWN: Interface Serial1, altered condition to up
2d18h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, adjusted state to up
R3(config-if)#
2d18h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, improved point out to down
The issue is always that one of several routers must act given that the DCE to ensure that the road protocol to come up and stay awake. If this had been your CCNA / CCNP home lab, you might just go around and look at the DTE/DCE cable to view which router experienced the DCE finish of the cable connected. In this example, even though, we don’t have physical access to the routers. How can we convey to which router has the DCE conclusion on the cable hooked up?
R3#display controller serial 1
HD unit 1, idb = 0x1C44E8, driver structure at 0x1CBAC8
buffer size 1524 High definition unit one, V.35 DCE cable
The clearly show controller command gives us this information and facts. (There’s http://www.bbc.co.uk/search?q=먹튀검증 quite a bit more output that this with this particular command, but it surely’s unimportant for our functions.) The router with the DCE end of your cable demands to provide a clock rate to your DTE, and we’ll just do that With all the interface-degree clockrate command.
R3#conf t
Enter configuration instructions, one particular for each line. Finish with CNTL/Z.
R3(config)#int serial1
R3(config-if)#clockrate 56000
In just some seconds, the road protocol goes up and stays up.
When troubleshooting a relationship, generally operate show interface 1st. If the thing is The mixture demonstrated underneath, the link is bodily wonderful but logically down. That’s normally the result of a essential keepalive not currently being present. With Frame Relay, it’s possibly an LMI difficulty, but with straight related serial interfaces The problem is most likely the DCE finish from the relationship not providing clockrate.
R3#demonstrate 토토먹튀 interface serial 1
Serial1 is up, line protocol is down
Troubleshooting is a large Element of the job, and it’s a big A part of the Cisco CCNA and CCNP packages at the same time. Know your exhibit and debug instructions and also you’re with your approach to passing the CCNA!