R0106-HP MSR Router Series Interface Configuration Guide(V7)

Verifying the configuration

# Verify the POS interface settings, for example, on Router A.

<RouterA> display interface pos

# Verify that Router A and Router B can ping each other at the POS interfaces. (Details not shown.)

Troubleshooting POS interfaces

Symptom 1

The physical state of the POS interface is down.

Solution

To resolve the problem:

• Verify that the POS interface is connected correctly to the remote port.

{ The transmit connector at one end must be connected to the receive connector at the other end.

{ The transmit and receive connectors of the POS interface are not connected by the same fiber.

If they are connected by the same fiber, the display interface command displays the "loopback

detected" message, whether or not the loopback detection feature is enabled.

• If the two POS interfaces are directly connected, verify that the two ends use different clock mode

settings.

• If the problem persists, contact HP Support.

Symptom 2

The physical layer is up, but the data link layer is down.

Solution

To resolve the problem:

• Verify that the two ends have matching clock mode, scrambling setting, and physical parameters.

• Verify that the two ends have the same data link layer protocol.

• If the problem persists, contact HP Support.

Symptom 3

A large amount of IP packets are dropped.

Solution

To resolve the problem:

• Verify that the correct clock mode is configured on the POS interface.

Incorrect clock mode setting can incur a large amount of CRC errors.

• Verify that the two ends have the same MTU setting.