Troubleshooting POS Interfaces 87# Configure interface POS 1/0.[RouterB] interface pos 1/0[RouterB-Pos1/0] clock slave# Configure Frame Relay encapsulation on the interface.[RouterB-Pos1/0] link-protocol fr[RouterB-Pos1/0] fr interface-type dte[RouterB-Pos1/0] ip address 10.10.10.2 255.255.255.0[RouterB-Pos1/0] fr map ip 10.10.10.1 70[RouterB-Pos1/0] mtu 1500Follow the same way to configure Router C.You can check interface connectivity with the display interface pos commandand test network connectivity with the ping command.Troubleshooting POSInterfacesSymptom 1:The physical state of POS interface is down.Solution:■ Check that the transmitting and receiving fibers-optic are correctly connectedto the POS interface. If you connect the two ends of a fiber-optic to thetransmitting end and the receiving end of the same POS interface, you can seethe message “loopback detected” on the screen when executing the displayinterface command even if you have not enabled loopback.■ If the two devices are directly connected back to back, one end of the POSinterfaces must be configured to use the master clock and the other end slaveclock.Symptom 2: The physical layer is up but the link is down.Solution:Check that:■ The configurations of clock, scrambling and other physical interfaces areconsistent on the connected two POS interfaces.■ The same link layer protocol is configured on two sides.■ Both ends are assigned IP addresses.Symptom 3:A great amount of IP packets are dropped.Solution:Check that:
