CCNA exam achievement relies upon mostly on noticing the small print, which is very true of configurations involving instantly connected serial interfaces. And of course, it’s not more than enough to notice these details – you’ve obtained to be aware of how to proceed 토토사이트 about them!
A Cisco router can be a DTE by default, but immediately connecting two DTEs using a DCE/DTE cable will not be sufficient. In the next illustration, R1 and R3 are instantly linked at their Serial1 interfaces. The line goes up briefly soon after currently being opened, but the line protocol goes down following about 30 seconds.
R3(config-if)#int s1
R3(config-if)#ip handle 172.12.13.3 255.255.255.0
R3(config-if)#no shutdown
2d18h: %Website link-3-UPDOWN: Interface Serial1, modified state to up
2d18h: %LINEPROTO-five-UPDOWN: Line protocol on Interface Serial1, adjusted condition to up
R3(config-if)#
2d18h: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, adjusted condition to down
The situation is the fact one of the routers has to act given that the DCE to ensure that the line protocol to return up and stay awake. If this had been your CCNA / CCNP residence lab, you could possibly just go around and think about the DTE/DCE cable to find out which router had the DCE finish of your cable hooked up. In this instance, nevertheless, we don’t have physical usage of the routers. How can we explain to which router has the DCE finish from the cable attached?
R3#show controller serial one
High definition device one, idb = 0x1C44E8, driver composition at 0x1CBAC8
buffer dimensions 1524 High definition unit one, V.35 DCE cable
The display controller command gives us this details. (There’s a lot more output that this with this command, but it really’s unimportant for our needs.) The router With all the DCE conclude of your cable desires to provide a clock fee towards the DTE, and we’ll do just that With all the interface-degree clockrate command.
R3#conf t
Enter configuration commands, one particular per line. Conclusion with CNTL/Z.
R3(config)#int serial1
R3(config-if)#clockrate 56000
In just a couple seconds, the line protocol goes up and stays up.
When troubleshooting a connection, always run exhibit interface to start with. If you see the combination shown under, the connection is bodily fantastic but logically down. That’s normally the results of a required keepalive not staying current. With Body Relay, it’s in all probability an LMI situation, but with straight related serial interfaces The problem is probably the DCE finish of your connection not providing clockrate.
R3#display interface serial one
Serial1 is up, line protocol is down
Troubleshooting is a big A part of The task, and it’s a major part of the Cisco CCNA and CCNP programs at the same time. http://www.bbc.co.uk/search?q=먹튀검증 Know your show and debug instructions and also you’re with your solution to passing the CCNA!