Cisco CCNA / 인스타 좋아요 CCNP Certification Exam: Troubleshooting Direct Serial Connections
A main matter of your respective CCNA and CCNP CIT tests will be connecting Cisco routers instantly through their Serial interfaces, and when the configuration is straightforward, usually there are some crucial particulars and demonstrate instructions you need to know in an effort to move the exams and configure this properly in creation and home lab networks. Enable’s take a look at a sample configuration.
Connecting Cisco routers straight by using their Serial interfaces will work rather well after https://en.wikipedia.org/wiki/?search=인스타 팔로워 구매 you get it running – and obtaining this type of connection up and jogging is a snap adequate. You should use show controller serial x to determine which endpoint is performing since the DCE, and it’s the DCE that has to be configured With all the clockrate command.
R3#display controller serial one
HD device 1, idb = 0x11B4DC, driver construction at 0x121868
buffer dimensions 1524 HD device 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 exciting results concerning the Bodily and logical state on the interfaces. Enable’s get rid of the clockrate from R3 and find out what takes place.
R3(config)#int s1
R3(config-if)#no clockrate 56000
R3(config-if)#
eighteen:02:19: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, altered condition to down
The road protocol doesn’t drop immediately, but it does fall. Permit’s run clearly show interface serial1 to compare the physical and rational interface states.
R3#demonstrate int serial1
Serial1 is up, line protocol is down
Bodily, the interface is okay, so the physical interface is up. It’s only the reasonable Section of the interface – the road protocol – that is definitely down. It’s precisely the same scenario on R1.
R1#present inter serial1
Whilst a router misconfiguration is definitely the more than likely reason for a serial relationship problem, that’s not the one reason for clocking troubles. Cisco’s Web-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 causes for clocking issues. Nonetheless, the number one basis for clocking challenges in my experience is solely forgetting to configure the clockrate command!