Lab Objective:
Learn how to troubleshoot and solve speed and duplex issues.
Lab Purpose:
Most network installation engineers will tell you that devices should never be left to auto-configure speed and duplex settings. It can often cause issues, especially when you mix equipment from different vendors.
Lab Tool:
Packet Tracer
Lab Topology:
Please use the following topology to complete this lab exercise:
Lab Walkthrough:
Task 1:
Drag a PC and router onto the canvas and connect them using a crossover cable. I used an 1841 model router.
Task 2:
In order to simulate issues, set the PC to half duplex 10 Mbps. Set the IP address to 192.168.1.2 and the gateway to 192.168.1.1.
Task 3:
Check the interface settings on the router interface F0/0. The interface will work with either 10 Mpbs or half-duplex devices. Mine is already up from a previous lab, but yours may be down until task 4.
Router#show int f0/0
FastEthernet0/0 is up, line protocol is up (connected)
Hardware is Lance, address is 000d.bd83.a601 (bia 000d.bd83.a601)
MTU 1500 bytes, BW 100000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Full-duplex, 100Mb/s, media type is RJ45
Task 4:
Set the router F0/0 interface to 192.168.1.1, the speed to 100 Mpbs, and the duplex to full. ‘No shut’ it.
Router#config t
Router(config)#interface FastEthernet0/0
Router(config-if)#ip address 192.168.1.1 255.255.255.0
Router(config-if)#no shut
Router(config-if)#speed 100
Router(config-if)#duplex full
Router(config-if)#end
Task 5:
Ping the router interface from the PC. It will fail. You would usually see router interface resets and errors, but we are a bit limited on Packet Tracer. The interface will be down on the router due to the fact that keepalives fail.
Router#show interfaces f0/0
FastEthernet0/0 is up, line protocol is down (disabled)
Hardware is Lance, address is 000d.bd83.a601 (bia 000d.bd83.a601)
Task 6:
Set the PC interface to full duplex and 100 Mbps. Devices are usually set to auto-detect, even though when you check, you see them working at 100/full.
Task 7:
Ping from the PC to the router.
Note:
The only way to really see errors and interface resets is to do this on live equipment.
