Cisco CCNA / CCNP Certification Examination: Troubleshooting Direct Serial Connections
A primary matter of your CCNA and CCNP CIT exams is going to be connecting Cisco routers instantly by means of their Serial interfaces, and although the configuration is simple, there are some important facts and show instructions you should know so as to move the tests and configure this productively in generation and residential lab networks. Enable’s Consider a sample configuration.
Connecting Cisco routers right by means of their Serial interfaces will work rather well after you get it jogging – and receiving such a connection up and functioning is straightforward enough. You can use clearly show controller serial x to learn which endpoint is acting since the DCE, and it’s the DCE that have to be configured Along with the clockrate command.
R3#exhibit controller serial one
HD unit 1, idb = 0x11B4DC, driver construction at 0x121868
buffer dimensions 1524 HD unit 1, V.35 DCE cable
R3(config)#int serial1
R3(config-if)#ip handle 172.twelve.13.three 255.255.255.0
R3(config-if)#clockrate 56000
R3(config-if)#no shut
Failure to configure the clockrate has some appealing outcomes regarding the Actual physical and sensible state with the interfaces. Enable’s take out the clockrate from R3 and see what comes about.
R3(config)#int s1
R3(config-if)#no clockrate 56000
R3(config-if)#
eighteen:02:19: %LINEPROTO-five-UPDOWN: Line protocol on Interface Serial1, transformed point out to down
The line protocol doesn’t fall immediately, but it does drop. Let’s run present interface serial1 to check the Bodily and reasonable interface states.
R3#clearly show int serial1
Serial1 is up, line protocol is down
Bodily, the interface is okay, And so the physical interface is up. It’s only the sensible Section of the interface – the line protocol – which is down. It’s the same predicament on R1.
R1#demonstrate inter serial1
Although a router misconfiguration is the most probably explanation for a serial connection problem, that’s not the one basis for clocking issues. Cisco’s Internet site documentation mentions CSU/DSU misconfiguration, out-of-spec cables, lousy patch panel connections, and connecting too many cables alongside one another as other good reasons for clocking difficulties. Nonetheless, the primary reason for clocking complications in my expertise is just forgetting 인스타 좋아요 늘리기 to configure the clockrate http://edition.cnn.com/search/?text=인스타 팔로워 구매 command!