Cisco CCNA / CCNP Certification Examination: Troubleshooting Direct Serial Connections
A primary topic of your respective CCNA and CCNP CIT tests will be connecting Cisco routers directly by way of their Serial interfaces, and although the 인스타 좋아요 늘리기 configuration is straightforward, there are several vital details and present instructions you will need to know in an effort to go the tests and configure this effectively in production and home lab networks. Permit’s Have a look at a sample configuration.
Connecting Cisco routers specifically by means of their Serial interfaces works rather well when you finally get it functioning – and receiving this type of relationship up and jogging is not difficult enough. You can utilize display controller serial x to learn which endpoint is performing as the DCE, and it’s the DCE that needs to be configured with the clockrate command.
R3#demonstrate controller serial one
High definition unit 1, idb = 0x11B4DC, driver composition at 0x121868
buffer sizing 1524 High definition unit 1, V.35 DCE cable
R3(config)#int serial1
R3(config-if)#ip handle 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 exciting consequences concerning the Actual physical and rational condition in the interfaces. Permit’s take out the clockrate from R3 and see what occurs.
R3(config)#int s1
R3(config-if)#no clockrate 56000
R3(config-if)#
eighteen:02:19: %LINEPROTO-five-UPDOWN: Line protocol on Interface Serial1, modified state to down
The road protocol doesn’t fall immediately, but it does drop. Enable’s operate display interface serial1 to compare the physical and sensible interface states.
R3#exhibit int serial1
Serial1 is up, line protocol is down
Physically, the interface is fine, And so the Actual physical interface is up. It’s only the sensible A part of the interface – the road protocol – which is down. It’s the identical problem on R1.
R1#clearly show inter serial1
Although a router misconfiguration could be the https://www.washingtonpost.com/newssearch/?query=인스타 팔로워 구매 most likely reason behind a serial connection issue, that’s not the sole cause of clocking troubles. Cisco’s Site documentation mentions CSU/DSU misconfiguration, out-of-spec cables, undesirable patch panel connections, and connecting too many cables alongside one another as other causes for clocking difficulties. Still, the number 1 cause for clocking troubles in my working experience is just forgetting to configure the clockrate command!