Arista DCS-7280CR3K-32P4A-R — 32×100GbE + 4×400GbE Switch Router with Rear-to-Front Airflow
The
Arista DCS-7280CR3K-32P4A-R is a 1RU switch router in the 7280R3 Series, delivering
4.8 Tbps of non-blocking switching capacity with
32 × 100GbE QSFP28 ports and
4 × 400GbE OSFP ports. Built on a deep buffer VOQ ASIC platform with
8 GB of packet buffer memory and
3.8 µs store-and-forward latency, the CR3K-32P4A provides full Layer 2/3 switch router capabilities including BGP, OSPF, IS-IS, MPLS (LDP, RSVP-TE, BGP LU), SR-TE, EVPN, VXLAN, and 512-way ECMP. The “A” variant features an
Eight-Core x86 CPU with
64 GB of standard DRAM,
120 GB SSD storage, and enhanced AlgoMatch capabilities for advanced packet classification and forwarding. The “
-R” suffix denotes
rear-to-front airflow, where cool air enters through the port side and exhausts from the non-port side. For front-to-rear airflow, see the
DCS-7280CR3K-32P4A-F.
Key Features at a Glance
- 32 × 100GbE QSFP28 ports supporting breakout to 50GbE, 40GbE (QSFP+), 25GbE, and 10GbE — up to 96 total interfaces
- 4 × 400GbE OSFP ports supporting 400G, 200G, and 100G line rates
- 4.8 Tbps non-blocking switching capacity with 2 Bpps forwarding rate
- 3.8 µs store-and-forward latency with 8 GB VOQ deep packet buffer — eliminates head-of-line blocking
- Full Layer 3 switch router: BGP, OSPF, IS-IS, MPLS (LDP, RSVP-TE, BGP LU), SR-TE, EVPN, VXLAN, 512-way ECMP
- K-variant FlexRoute: Over 5M IPv4 unicast routes, over 5M IPv6 routes, 384K MAC addresses, Algorithmic ACLs (100K+ rules)
- Eight-core x86 CPU with 64 GB DRAM and 120 GB SSD running Arista EOS
- IEEE 1588v2 PTP and SyncE hardware-assisted precision timing for 5G and carrier environments
- Telemetry: LANZ, Accelerated sFlow, Advanced Event Management (AEM), DANZ, streaming telemetry via gNMI and eAPI
- CloudVision integration, Zero-Touch Provisioning (ZTP), Python/Bash scripting, OpenConfig
- Hot-swappable dual PSU (1+1) and N+1 fan trays; rear-to-front (-R) airflow
- 1RU form factor — 543W typical / 865W maximum power draw
- BrightStar Systems: Available from BrightStar Systems fully tested, reset to factory defaults, and backed by a 1-year in-house warranty
4.8 Tbps Non-Blocking VOQ Architecture
The DCS-7280CR3K-32P4A-R delivers
4.8 Tbps of full-duplex, non-blocking throughput — (32 × 100 Gbps) + (4 × 400 Gbps) in both directions simultaneously. The
Virtual Output Queue (VOQ) ASIC architecture maintains separate queues for each input-to-output port pair, eliminating head-of-line blocking. With a
2 Bpps forwarding rate, the switch operates at full line rate across all port combinations regardless of traffic mix or packet size distribution. The
8 GB deep packet buffer is distributed across the VOQ structure, providing substantial burst absorption capacity. The VOQ deep buffer architecture handles transient congestion, TCP incast events, and bursty traffic patterns without triggering early packet drops or ECN marking — delivering higher effective throughput in oversubscribed topologies.
3.8 µs Store-and-Forward Latency
The 7280CR3K-32P4A-R operates in store-and-forward mode with a measured latency starting from
3.8 microseconds. The ASIC receives the complete packet, performs a full Layer 2/3 lookup, applies ACLs and QoS policies, and forwards the packet — all within 3.8 µs. This design provides the ability to buffer, inspect, and apply policy at every forwarding decision, while maintaining sub-10-microsecond performance suitable for enterprise, service provider, and data center applications.
Port Configuration and Optics
The 7280CR3K-32P4A-R provides 32 × 100GbE QSFP28 ports and 4 × 400GbE OSFP ports:
- 32 × 100GbE QSFP28: Supporting 100G, 50G, 40G (QSFP+), 25G, and 10G via breakout cables.
- 4 × 400GbE OSFP: Supporting 400G, 200G, and 100G line rates.
- Management: 1 × 100/1000 Mbps out-of-band management port + 1 × RS-232 RJ-45 console port, independent of the forwarding plane.
- Maximum port configurations: Up to 4 × 400G, 48 × 100G, 96 × 50G, 36 × 40G (QSFP+), or 96 × 25G/10G interfaces. Maximum 96 total interfaces.
Layer 2/3 Switch Router Capabilities
The 7280CR3K-32P4A-R operates as a unified switch router with full Layer 2 and Layer 3 feature sets:
- BGP Full-Table Routing: Over 5M IPv4 unicast routes, over 5M IPv6 routes, 384K MAC addresses in the hardware FIB via FlexRoute. Supports MP-BGP, BGP graceful restart, BGP RPKI, and 512-way ECMP for load balancing across equal-cost paths.
- MPLS: Line-rate MPLS label switching with LDP, RSVP-TE, and BGP Labeled Unicast (BGP LU) for carrier-grade MPLS networks and VPN services.
- Segment Routing: SR-TE (Segment Routing with Traffic Engineering), TI-LFA for fast convergence, OSPF-SR, ISIS-SR, and BGP-SR.
- EVPN and VXLAN: VXLAN Tunnel Endpoint (VTEP) and EVPN control plane for multi-tenant overlay networks, data center interconnect, and MAC mobility. EVPN Integrated Routing and Bridging (IRB) for seamless L2/L3 overlays.
- Routing Protocols: OSPF, OSPFv3, IS-IS, RIPv2, VRF, BFD, Micro BFD, uRPF, VRRP/VRRPv3, VARP, PBR, BGP FlowSpec, and Prefix-Independent Convergence (PIC).
- Layer 2: 802.1w/s Spanning Tree, RPVST+, 4096 VLANs, Q-in-Q, 802.3ad LACP (256 ports/channel, 2048 groups), MLAG (512 ports per MLAG), Jumbo Frames, IGMP snooping.
- L2/L3 VPN Services: IP-VPN, EVPN over VXLAN and MPLS, LDP pseudowires, VPLS.
Precision Timing
- PTP IEEE 1588v2: Hardware-assisted Precision Time Protocol supporting Boundary Clock and Transparent Clock modes, with PTP profiles G.8275.1, G.8275.2, and G.8261.
- SyncE: Synchronous Ethernet per ITU-T G.8264 for frequency distribution in carrier and 5G environments.
Telemetry, Monitoring, and Analytics
- LANZ (Latency Analyzer): Per-port, real-time microburst detection and queue depth monitoring at microsecond granularity. Records egress port, queue, drop reason, and timestamp for every congestion event.
- Accelerated sFlow: Hardware-accelerated sampled packet telemetry for flow analysis and capacity planning.
- Streaming Telemetry: Real-time counter and state export via gNMI (gRPC) and Arista eAPI (REST). Supports OpenConfig data models for vendor-neutral management.
- Advanced Event Management (AEM): Programmable event-driven automation within EOS — customize alerts and actions, automate routine tasks, and respond to real-time network conditions.
- DANZ: Arista’s telemetry fabric for advanced mirroring, SPAN/TAP aggregation, and L2/3/4 filtering.
- IPFIX: IP Flow Information Export for detailed traffic flow analytics.
- Ethernet OAM: CFM, Loss Measurement (LM), Synthetic Loss Measurement (SLM), Delay Measurement (DM), TWAMP, and Link Fault Signaling.
EOS Automation and Provisioning
The 7280CR3K-32P4A-R runs
Arista EOS, a modular operating system built on a standard Linux kernel where each process runs in its own protected memory space and communicates through an in-memory state-sharing database (Sysdb). This architecture enables in-service software updates and self-healing resiliency without data plane interruption.
- CloudVision: Centralized configuration management, network-wide change control, topology visualization, and compliance monitoring across multi-site Arista deployments.
- Zero-Touch Provisioning (ZTP): Automatic configuration download on first power-up via DHCP — no manual CLI access required for initial deployment.
- Python and Bash: Native on-box scripting with full Linux shell access for custom event handlers and automation workflows.
- eAPI (JSON-RPC): RESTful programmatic interface to all configuration and operational commands. Integrates with Ansible, Terraform, and custom orchestration.
- OpenConfig and gNMI: Vendor-neutral data models and high-performance streaming RPC for configuration and telemetry.
- NETCONF and RESTCONF: Standards-based configuration management interfaces.
Security
- Control Plane Policing (CoPP): Rate-limiting of CPU-destined traffic to protect routing stability
- ACLs: Ingress/egress access control lists at L2, L3, and L4 enforced in the ASIC at line rate. Scalable Algorithmic ACLs supporting over 100,000 rules.
- User-Defined Fields (UDF): Custom packet matching for flexible filtering policies
- TACACS+ and RADIUS: Centralized authentication and accounting for administrative access
- Secure Boot: Cryptographic verification of bootloader and EOS image integrity with hardware trust anchors
- MAC Security, DHCP Relay/Snooping, ARP trapping for Layer 2 security enforcement
Note: MACsec (IEEE 802.1AE) is supported on M and MK model variants only. The CR3K-32P4A is not an M or MK model and does not include MACsec.
Quality of Service (QoS)
- Up to 8 queues per port with strict priority, weighted round-robin (WRR), and weighted fair queueing (WFQ)
- 802.1p and DSCP classification and remarking
- ECN (Explicit Congestion Notification) marking for TCP-friendly congestion signaling
- PFC (Priority Flow Control) and DCBX (Data Center Bridging Exchange) for converged traffic
- Hierarchical QoS (H-QoS) for granular traffic management
Physical Specifications
- Form Factor: 1RU — 17.3 × 1.72 × 22.0 inches (43.99 × 4.37 × 55.83 cm)
- Weight: 27 lbs (12.27 kg)
- Power: 543W typical / 865W maximum; PWR-1011 AC or DC power supplies
- Redundancy: Dual hot-swappable PSU (1+1) and 3 hot-swappable FAN-7011H fan trays (N+1)
- Storage: 8 GB Flash, 120 GB SSD, 1 × USB port
- System Memory: 64 GB DRAM (A-variant standard), 8 GB packet buffer
Lifecycle and Reliability
- Self-Healing Software: EOS includes Stateful Fault Repair (SFR) for automatic recovery from software faults without data plane impact, and Stateful Fault Containment (SFC) for fault isolation.
- In-Service Software Updates: Dual-partition boot with Smart System Upgrade (SSU) and Accelerated Software Update (ASU) for planned upgrades with minimal disruption.
- Configuration Rollback: Instant rollback to previous configuration snapshots via EOS configuration replace.
- BrightStar Systems 1-Year Warranty: Supplied fully tested, reset to factory defaults, and backed by a 1-year in-house warranty.
Scalability and Table Sizes
- MAC Addresses: 384K
- IPv4 Unicast Routes: Over 5M (FlexRoute K-variant)
- IPv6 Unicast Routes: Over 5M (FlexRoute K-variant)
- Algorithmic ACLs: Over 100K rules
- ECMP: 512-way
- LACP: 256 ports/channel, 2048 groups, 512 ports per MLAG
- Minimum EOS: 4.27.2
- EOS Feature License: Group 3
Similar Arista Models to Consider
- DCS-7280CR3-36S-F: 36 QSFP ports with flexible 1/10/25/40/50/100/200/400G breakout capability; 2.4 Tbps throughput
- DCS-7280CR3K-96-F: 96 × QSFP28 ports; 9.6 Tbps throughput; 16 GB packet buffer; 2U form factor
- DCS-7280SR3K-48YC8-F: 48 × 25G SFP + 8 × 100G QSFP ports; 2 Tbps throughput; optimized for leaf deployments
Related 7280R3 Series Resources
For comprehensive technical documentation and comparative model information across the Arista 7280 family, visit
Arista 7280 Series Overview.
Summary
The Arista DCS-7280CR3K-32P4A-R is a 1RU switch router combining 32 × 100GbE QSFP28 ports with 4 × 400GbE OSFP ports, 4.8 Tbps non-blocking throughput, 8 GB VOQ deep packet buffer, and full Layer 2/3 capabilities including BGP, MPLS, SR-TE, EVPN, and VXLAN. The A-variant delivers enhanced CPU performance with eight cores, 64 GB DRAM and 120 GB SSD with over 5M IPv4 routes via FlexRoute. Running Arista EOS with CloudVision integration, ZTP, precision timing (PTP/SyncE), and comprehensive telemetry (LANZ, Accelerated sFlow, AEM, DANZ), the 7280CR3K-32P4A-R is available from BrightStar Systems fully tested, reset to factory defaults, and backed by a 1-year in-house warranty.
