Duplex Mismatch

A duplex mismatch is also possible, though this is more common on circuits 100Mbit/s or less. Some providers are stuck in the stone age and still insist on hard-coding ports on CPEs such as fiber converters at 100Mbit/s full-duplex. If the CPE is hard-coded but the firewall is not, it would show as using 100Mbit/s half-duplex on Status > Interfaces. The duplex mismatch will lead to interface errors, collisions, and low throughput.