Cisco CCNA / CCNP Certification Test: Troubleshooting Immediate Serial Connections
A primary matter of one's https://www.washingtonpost.com/newssearch/?query=인스타 팔로워 구매 CCNA and CCNP CIT tests will likely be connecting Cisco routers instantly by way of their Serial interfaces, and though the configuration is easy, there are numerous crucial details and exhibit instructions you will need to know so that you can go the exams and configure this productively in production and home lab networks. Let’s Examine a sample configuration.
Connecting Cisco routers specifically by way of their Serial interfaces performs rather well as soon as you get it operating – and having this kind of 인스타 좋아요 늘리기 link up and operating is not difficult sufficient. You can utilize display controller serial x to find out which endpoint is performing given that the DCE, and it’s the DCE that should be configured While using the clockrate command.
R3#show controller serial 1
HD unit one, idb = 0x11B4DC, driver composition at 0x121868
buffer dimensions 1524 High definition device 1, V.35 DCE cable
R3(config)#int serial1
R3(config-if)#ip address 172.twelve.13.3 255.255.255.0
R3(config-if)#clockrate 56000
R3(config-if)#no shut
Failure to configure the clockrate has some appealing results concerning the Actual physical and logical condition with the interfaces. Enable’s remove the clockrate from R3 and find out what comes about.
R3(config)#int s1
R3(config-if)#no clockrate 56000
R3(config-if)#
18:02:19: %LINEPROTO-five-UPDOWN: Line protocol on Interface Serial1, altered point out to down
The road protocol doesn’t drop promptly, but it really does fall. Let’s operate present interface serial1 to compare the Actual physical and logical interface states.
R3#clearly show int serial1
Serial1 is up, line protocol is down
Bodily, the interface is fine, Therefore the Bodily interface is up. It’s just the logical Element of the interface – the road protocol – that may be down. It’s precisely the same scenario on R1.
R1#exhibit inter serial1
Even though a router misconfiguration will be the probably cause of a serial link problem, that’s not the one cause of clocking concerns. Cisco’s website documentation mentions CSU/DSU misconfiguration, out-of-spec cables, bad patch panel connections, and connecting too many cables collectively as other motives for clocking complications. Nonetheless, the number one reason behind clocking difficulties in my experience is simply forgetting to configure the clockrate command!