Arista H-D400-4Q100-1M-Arista | 400G QSFP-DD to 4x 100G QSFP28 Active DAC, 1m

Q: What is the primary use case for this breakout cable?
A: The H-D400-4Q100-1M enables a single 400G QSFP-DD port on a switch or router to connect to four separate 100G QSFP28 devices, maximising port density in data centre environments and allowing 400G infrastructure to support legacy 100G equipment.

Q: Is this cable compatible with all vendors' QSFP-DD and QSFP28 ports?
A: This cable is designed for Arista switches and routers with 400G QSFP-DD ports. While it conforms to industry MSA standards, compatibility with other vendors should be verified before deployment. Consult Arista's transceiver compatibility guide for supported platforms.

Q: What is the difference between active and passive DAC cables?
A: Active DAC cables incorporate signal amplification and conditioning electronics, allowing longer reach and better signal integrity than passive cables. This active design supports 400G breakout applications reliably over the 1-meter length.

Q: Can this cable be used in both directions for traffic?
A: Yes, the cable supports full-duplex bidirectional traffic, allowing simultaneous transmit and receive on all four 100G connections for a total aggregate throughput of 400Gbps.

Q: Does this cable require any special configuration or licensing?
A: No special software licensing is required. The cable is hot-pluggable and will be recognised automatically by compatible Arista devices. Port configuration follows standard Arista EOS breakout commands to enable the 4x100G mode.