Supported Loopback Types for Serial Interfaces on Juniper Devices

AC

For serial interfaces Juniper devices support the local and the remote loopback types.

In Juniper devices, there are two loopback types supported for serial interfaces: Local and Remote loopbacks.

1. Local Loopback: A Local Loopback is a loopback that is performed on the same device where the interface is located. When a local loopback is enabled on a serial interface, the transmitted data is looped back to the same interface without actually transmitting over the cable. This is useful for testing the physical interface, signaling, or software running on the local device. The local loopback command is configured on the Juniper device using the "set interfaces <interface-name> unit <unit-number> family <family-type> local-loopback" command.

2. Remote Loopback: A Remote Loopback is a loopback that is performed on the remote device at the other end of the cable. When a remote loopback is enabled on a serial interface, the transmitted data is looped back to the same interface, but the loopback occurs at the remote device. This is useful for testing the physical interface and signaling on the remote device. The remote loopback command is configured on the Juniper device using the "set interfaces <interface-name> unit <unit-number> family <family-type> remote-loopback" command.

Therefore, the correct answer is A. Local and C. Remote. Far End loopback is not a supported loopback type for serial interfaces on Juniper devices.