Arista DCS-7800R3A-36DM-LC | 7800R3 36-Port 400G QSFP-DD Line Card, MACsec

Q: What chassis platforms support the DCS-7800R3A-36DM-LC line card?
A: This line card is compatible with all Arista 7800R3 Series modular chassis including the 4-slot 7804R, 8-slot 7808R, 12-slot 7812R, and 16-slot 7816R systems. It can be hot-swapped and intermixed with other 7800R3 and 7800R3A series line cards for flexible deployment.

Q: What encryption capabilities does this line card provide?
A: The DCS-7800R3A-36DM-LC includes enhanced MACsec (IEEE 802.1AE) encryption capabilities that provide wire-speed, line-rate frame encryption and authentication on all 400G ports. MACsec operates at the link layer for point-to-point encryption with AES-256-GCM block cipher, ensuring confidentiality and anti-replay protection without performance penalty.

Q: Can each 400G port be broken out to lower speeds?
A: Yes, each 400GbE QSFP-DD port supports flexible breakout configurations including 4x100G, 2x200G, and further breakout to 50G and 25G speeds, providing deployment flexibility to match diverse connectivity requirements across data center spine, core, and peering applications.

Q: What makes the FlexRoute engine beneficial for routing deployments?
A: The FlexRoute engine provides a flexible database approach to forwarding tables, allowing dynamic allocation of resources for MAC, routing, host, and ARP entries. It supports internet-scale routing with efficient memory utilization and fast convergence while maintaining low power consumption, making it ideal for service provider peering and large-scale cloud networks.

Q: Is this line card suitable for latency-sensitive applications?
A: Yes, the deep buffer Virtual Output Queue architecture eliminates head-of-line blocking and provides deterministic, fair forwarding even under congestion. With approximately 40ms of buffer per port and wire-speed forwarding, it delivers consistent low latency performance for real-time, multicast, and storage traffic in mission-critical data center environments.