Arista H-D400-4Q100-2M-Arista | 400G Breakout DAC, QSFP-DD to 4x 100G QSFP28, 2m

Q: What is the primary use case for this breakout cable?
A: The H-D400-4Q100-2M enables migration to 400G infrastructure while maintaining connectivity to existing 100G equipment. It is commonly used in leaf-spine data center architectures to connect a 400G spine switch to four separate 100G leaf switches or servers, maximizing port density and reducing cabling complexity.

Q: Is this cable compatible with other vendor equipment?
A: While designed for Arista switches and routers with QSFP-DD and QSFP28 ports, this cable follows MSA standards and is typically compatible with other vendors' equipment that support 400GBASE-CR8 and 100GBASE-CR4 standards. Always verify compatibility with your specific hardware before deployment.

Q: What is the difference between active and passive twinax cables?
A: Active twinax cables like the H-D400-4Q100-2M include signal amplification and conditioning circuitry in the cable assembly, enabling longer reach and better signal integrity than passive cables. Active cables are recommended for 2-meter and longer deployments, especially for high-speed 400G breakout applications.

Q: Can this cable be used to aggregate four 100G ports into one 400G port?
A: Yes, the cable is bidirectional and supports both breakout and aggregation scenarios. You can connect four 100G QSFP28 ports to a single 400G QSFP-DD port, depending on your switch configuration and requirements. The switch must support the appropriate port channeling or aggregation features.

Q: Does Arista offer this cable in other lengths?
A: Yes, Arista offers the H-D400-4Q100 series in multiple lengths including 1m, 2m, 3m, and 5m variants to accommodate different rack configurations and data center layouts. Select the appropriate length based on your inter-switch distance requirements.