Cisco CCNA / CCNP Certification Test: Troubleshooting Immediate Serial Connections
A prime topic of your respective CCNA and CCNP CIT exams might be connecting Cisco routers directly via their Serial interfaces, and even though the configuration is simple, there are some critical aspects and display commands you will need to know in an effort to pass the examinations and configure this correctly in production and home lab networks. Let’s Check out a sample configuration.
Connecting 인스타 좋아요 Cisco routers right by way of their Serial interfaces operates really well when you finally get it operating http://edition.cnn.com/search/?text=인스타 팔로워 구매 – and finding such a connection up and operating is not hard enough. You can utilize clearly show controller serial x to see which endpoint is performing given that the DCE, and it’s the DCE that have to be configured with the clockrate command.
R3#display controller serial 1
HD unit 1, idb = 0x11B4DC, driver framework at 0x121868
buffer dimension 1524 HD unit one, V.35 DCE cable
R3(config)#int serial1
R3(config-if)#ip address 172.twelve.thirteen.three 255.255.255.0
R3(config-if)#clockrate 56000
R3(config-if)#no shut
Failure to configure the clockrate has some appealing effects concerning the physical and logical condition from the interfaces. Enable’s remove the clockrate from R3 and find out what transpires.
R3(config)#int s1
R3(config-if)#no clockrate 56000
R3(config-if)#
18:02:19: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, altered condition to down
The road protocol doesn’t fall immediately, nonetheless it does drop. Enable’s run present interface serial1 to compare the Bodily and rational interface states.
R3#display int serial1
Serial1 is up, line protocol is down
Physically, the interface is okay, Hence the physical interface is up. It’s just the rational A part of the interface – the road protocol – that may be down. It’s the exact same scenario on R1.
R1#exhibit inter serial1
Whilst a router misconfiguration could be the almost certainly cause of a serial connection problem, that’s not the only real cause of clocking issues. Cisco’s Site documentation mentions CSU/DSU misconfiguration, out-of-spec cables, terrible patch panel connections, and connecting a lot of cables alongside one another as other reasons for clocking difficulties. Continue to, the primary basis for clocking troubles in my working experience is actually forgetting to configure the clockrate command!