CCNA Test results is dependent mostly on noticing the small print, which is very true of configurations involving straight connected serial interfaces. Not to mention, it’s not more than enough to notice these details – you’ve bought to be aware of how to proceed about them!
A Cisco router can be a DTE by default, but directly connecting two DTEs using a DCE/DTE cable just isn't sufficient. In the following illustration, R1 and R3 are directly linked at their Serial1 interfaces. The road goes up briefly following getting opened, but the line protocol goes down following about 30 seconds.
R3(config-if)#int s1
R3(config-if)#ip deal with 172.twelve.13.3 255.255.255.0
R3(config-if)#no shutdown
2d18h: %Backlink-3-UPDOWN: Interface Serial1, altered condition to up
2d18h: %LINEPROTO-five-UPDOWN: Line protocol on Interface Serial1, adjusted state to up
R3(config-if)#
2d18h: %LINEPROTO-five-UPDOWN: Line protocol on Interface Serial1, altered point out to down
The challenge is always that one of many routers needs to act because the DCE in order for the line protocol to return up and stay up. If this were being your CCNA / CCNP property lab, you can just go above and think about the DTE/DCE cable to check out which router had the DCE stop of your cable hooked up. In this example, even though, we don’t have Bodily usage of the routers. How can we notify which router has the DCE end with the cable attached?
R3#present controller serial one
High definition unit 1, idb = 0x1C44E8, driver structure at 0x1CBAC8
buffer dimension 1524 High definition device one, V.35 DCE cable
The display controller command presents us this information and facts. (There’s a whole lot additional output this with this particular command, but it surely’s unimportant for our reasons.) The router While using https://en.wikipedia.org/wiki/?search=먹튀검증 the DCE stop with the cable wants to provide a clock charge to the DTE, and we’ll do just that Using the interface-degree clockrate command.
R3#conf t
Enter configuration instructions, just one per line. Conclusion 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 connection, often operate present interface first. If you see The mix revealed under, the connection is bodily great but logically down. That’s frequently the results of a essential keepalive not getting existing. With Body Relay, it’s in all probability an LMI difficulty, but with right connected serial interfaces the issue is more than likely the DCE end from the relationship not giving clockrate.
R3#show interface serial 1
Serial1 is up, line protocol is down
Troubleshooting is a large A part of The work, and it’s a huge 토토사이트 Section of the Cisco CCNA and CCNP applications too. Know your present and debug commands and you simply’re with your technique to passing the CCNA!