Cisco CCNA / CCNP Certification Test: Troubleshooting Immediate Serial Connections
A primary subject of your respective CCNA and CCNP CIT exams will be connecting Cisco routers immediately through their Serial interfaces, and even though the configuration is simple, there are numerous critical details and present instructions you should know to be able to pass the exams and configure this correctly in output and home lab networks. Permit’s Check out a sample configuration.
Connecting Cisco routers instantly by means of their Serial interfaces functions http://edition.cnn.com/search/?text=토토사이트 very well when you finally get it functioning – and finding such a connection up and operating is a snap more than enough. You need to use display controller serial x to discover which endpoint is performing as the DCE, and it’s the DCE that has to be configured With all the clockrate command.
R3#show controller serial one
High definition unit one, idb = 0x11B4DC, driver structure at 0x121868
buffer dimension 1524 High definition unit 1, V.35 DCE cable
R3(config)#int serial1
R3(config-if)#ip address 172.12.13.three 255.255.255.0
R3(config-if)#clockrate 56000
R3(config-if)#no shut
Failure to configure the clockrate has some fascinating consequences regarding the Actual physical and sensible point out with the interfaces. Enable’s take away the clockrate from R3 and find out 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, changed state to down
The road protocol doesn’t fall promptly, nonetheless it does fall. Permit’s run display interface serial1 to check the physical and reasonable interface states.
R3#present int serial1
Serial1 is up, line protocol is down
Physically, the interface is okay, so the physical interface is up. It’s only the reasonable Portion of the interface – the line protocol – which is down. It’s a similar problem on R1.
R1#display inter serial1
Even though a router misconfiguration could be the probably reason for a serial relationship problem, that’s not the sole reason for clocking problems. Cisco’s Site documentation mentions CSU/DSU misconfiguration, out-of-spec cables, negative patch panel connections, and connecting too many cables together as other causes for clocking problems. Continue to, 안전놀이터 the number 1 basis for clocking challenges in my expertise is simply forgetting to configure the clockrate command!