Arista DCS-7280CR3-36S-F — 36×QSFP28 Multi-Speed Switch Router with Front-to-Rear Airflow
The Arista DCS-7280CR3-36S-F is a compact, high-performance 1RU switch router from the Arista 7280R3 family. It delivers 2.4 Tbps of wire-speed, non-blocking switching capacity with 36 QSFP28/QSFP+ ports supporting flexible multi-speed operation (1/10/25/40/50/100/200G and 400G breakout). Built on a high-throughput ASIC platform with 4 GB of packet buffer memory and 3.8 µs store-and-forward latency, the 7280CR3-36S provides full Layer 2/3 switch router capabilities — comprehensive routing protocols, MPLS, Segment Routing, EVPN, VXLAN, and 512-way ECMP — with exceptional forwarding scale and flexible optics support for diverse network deployments.
The “-F” suffix denotes front-to-rear (forward) airflow, where cool air enters from the non-port side and exhausts from the port side of the chassis. For rear-to-front airflow, see the DCS-7280CR3-36S-R.
Key Features at a Glance
- 36 × QSFP28/QSFP+ ports supporting flexible multi-speed operation: 1G, 10G, 25G, 40G, 50G, 100G, 200G, and 400G breakout modes for optimized port utilization
- 2.4 Tbps non-blocking switching capacity with 800 Mpps forwarding rate
- 3.8 µs store-and-forward latency with 4 GB packet buffer — eliminates head-of-line blocking
- Full Layer 3 switch router: BGP, OSPF, OSPFv3, IS-IS, MPLS (LDP, RSVP-TE, BGP-LU), SR-MPLS, SR-TE, EVPN, VXLAN, 512-way ECMP
- Over 2M IPv4 LPM routes, 1.4M+ IPv6 routes, 384K MAC addresses — exceptional routing scale for large networks
- Quad-core x86 CPU with 8 GB DRAM (64 GB optional) running Arista EOS
- IEEE 1588v2 PTP, SyncE, G.8275.1/2, G.8261/8264 for precision timing in synchronization-critical deployments
- Telemetry: LANZ, sFlow, Advanced Event Management (AEM), DANZ, Inband Network Telemetry (INT), IPFIX, streaming telemetry via gNMI
- CloudVision integration, Zero-Touch Provisioning (ZTP), Python/Bash scripting, eAPI, NETCONF, RESTCONF, OpenConfig
- Hot-swappable dual PSU (1+1) and 3-fan architecture (N+1); front-to-rear (-F) airflow
- 1RU form factor — compact design with flexible deployment options
- BrightStar Systems: Supplied fully tested, reset to factory defaults, and backed by a 1-year in-house warranty
2.4 Tbps Non-Blocking High-Throughput Architecture
The DCS-7280CR3-36S-F delivers 2.4 Tbps of full-duplex, non-blocking throughput across 36 flexible QSFP28 ports in the third-generation R3 design. The advanced ASIC architecture maintains separate queues for each input-to-output port pair, eliminating head-of-line blocking. With a 800 Mpps forwarding rate, the switch operates at full line rate across all port combinations regardless of traffic mix, packet size distribution, or speed mix configuration.
The 4 GB packet buffer is architected to handle transient congestion, TCP incast events, and bursty traffic patterns without triggering early packet drops or ECN marking — delivering higher effective throughput in oversubscribed topologies and multi-speed environments. The R3 architecture supports up to 512-way ECMP for advanced load balancing and faster convergence.
3.8 µs Store-and-Forward Latency
The 7280CR3-36S-F operates in store-and-forward mode with a measured latency of 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 enables comprehensive policy enforcement and traffic inspection at every forwarding decision while maintaining sub-10-microsecond performance suitable for enterprise, service provider, and data center applications.
Port Configuration and Multi-Speed Flexibility
The 7280CR3-36S-F provides 36 QSFP28/QSFP+ ports with flexible multi-speed support:
- 36 × QSFP28/QSFP+: Support for 100GBASE-SR4, LR4, DR, FR, CWDM4, ZR/ZR+, and DAC/AOC cables. Flexible speed support: 1G, 10G, 25G, 40G, 50G, 100G, 200G native modes, and 400G breakout configurations for maximum port density optimization.
- Management: 1 × 100/1000 Mbps out-of-band management port + 1 × RS-232 RJ-45 console port, independent of the forwarding plane.
- Flexible port configurations: Operators can optimize port density based on topology requirements — native 36×100G, or breakout to 400G per-port or mixed-speed configurations for cost-effective deployment.
Layer 2 Switching Capabilities
The 7280CR3-36S-F operates as a unified switch router with comprehensive Layer 2 switching features:
- 802.1w/s Spanning Tree: RPVST+ for loop prevention and redundancy
- VLAN Support: 4096 VLANs with Q-in-Q capabilities for service provider deployments
- Link Aggregation: 802.3ad LACP with 256 ports per channel and 2048 groups for high-density bonding
- MLAG (Multi-Chassis LAG): Up to 512 ports per MLAG for flexible redundancy across multiple chassis
- Jumbo Frames: Support for frames up to 9216 bytes
- IGMP Snooping: IP multicast group filtering and management
Layer 3 Routing and Advanced Forwarding
The 7280CR3-36S-F delivers industry-leading Layer 3 routing capabilities:
- BGP Full-Table Routing: Over 2M IPv4 unicast LPM routes, 1.4M+ IPv6 routes in hardware FIB. Supports MP-BGP, BGP graceful restart, BGP FlowSpec, BMP, BGP-RPKI, and 512-way ECMP for sophisticated load balancing.
- Interior Gateway Protocols: OSPF, OSPFv3, IS-IS, RIPv2 with BFD and Micro BFD for sub-second convergence
- VRF and Policy: Virtual Routing and Forwarding (VRF), Policy-Based Routing (PBR), and Prefix Independent Convergence (PIC) for fast reroute
- VRRP and VARP: Virtual Router Redundancy Protocol and Virtual ARP for gateway redundancy
- Unicast RPF: Reverse path forwarding for source validation and anti-spoofing
MPLS and Segment Routing
The 7280CR3-36S-F provides carrier-grade MPLS and advanced traffic engineering:
- MPLS Label Switching: LDP, RSVP-TE with Fast Reroute (FRR), and BGP Labeled Unicast (BGP-LU) for seamless VPN and carrier services
- BGP-LS: BGP Link State for topology discovery and distribution in SDN controllers
- Segment Routing (SR): SR-MPLS and SR-TE (Segment Routing Traffic Engineering) for simplified, source-driven path optimization without per-path LSP state in the network core
- TI-LFA: Topology-Independent Loop-Free Alternate for sub-50ms local reroute protection
VPN and Overlay Services
The 7280CR3-36S-F enables flexible VPN deployments across Layer 2 and Layer 3 domains:
- IP-VPN: BGP/MPLS IPv4 and IPv6 VPN (RFC 4364/4659) for carrier-grade multi-tenant service delivery
- VPLS: Virtual Private LAN Service for Layer 2 VPN connectivity
- EVPN-VXLAN: Ethernet VPN with VXLAN Tunnel Endpoints (VTEP) for multi-tenant data center overlays and MAC mobility
- EVPN-MPLS: Ethernet VPN over MPLS for carrier-grade Layer 2 services
- EVPN IRB (Integrated Routing and Bridging): Seamless Layer 2/3 virtualization for efficient multi-tenant and multi-domain networks
Precision Timing and Synchronization
The 7280CR3-36S-F includes comprehensive timing support for synchronization-critical deployments:
- IEEE 1588v2 PTP: Hardware-assisted Precision Time Protocol for network clock synchronization, supporting Boundary Clock and Transparent Clock modes
- Synchronous Ethernet (SyncE): G.8261, G.8262 for frequency synchronization over Ethernet
- Telecom Timing Standards: G.8275.1 and G.8275.2 for phase/time synchronization in telecom and financial networks
- G.8264: MPLS Section and Span Loss of Signal monitoring for timing chain integrity
Quality of Service (QoS)
The 7280CR3-36S-F provides advanced QoS for multi-service networks:
- 8 queues per port with strict priority, weighted round-robin (WRR), and weighted fair queueing (WFQ)
- Classification: DSCP and 802.1p tag-based priority mapping with remarking support
- ECN (Explicit Congestion Notification): DCTCP-friendly congestion signaling for reduced packet loss in oversubscribed networks
- PFC (Priority Flow Control) and DCBX: Data Center Bridging Exchange for lossless Ethernet and converged traffic
- Hierarchical QoS (H-QoS): Multi-level queue structures for complex traffic policies and SLA guarantees
- Egress shaping and policing per-interface and per-queue
Security
- Control Plane Policing (CPP): Rate-limiting of CPU-destined traffic to protect routing stability
- ACLs and User-Defined Fields (UDF): Ingress/egress access control lists at L2, L3, and L4 with 100K+ Algorithmic ACL entries for sophisticated packet filtering and rate limiting
- TACACS+ and RADIUS: Centralized authentication and accounting for administrative access
- Secure Boot: Cryptographic verification of bootloader and EOS image integrity
- Layer 2 Security: DHCP Relay/Snooping and ARP trapping for Layer 2 security enforcement (Note: MACsec is not supported on CR3-36S)
Telemetry, Monitoring, and Analytics
The 7280CR3-36S-F provides comprehensive network visibility:
- 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 v5: Industry-standard traffic sampling for flow analysis and capacity planning. Integrates with third-party collectors (Kentik, Splunk, Solarwinds).
- 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: Advanced mirroring and traffic analysis with configurable M:N aggregation and L2/3/4 filtering for deep packet inspection.
- Inband Network Telemetry (INT): Embedded telemetry in packet headers for hop-by-hop analytics and performance visibility
- IPFIX: IP Flow Information Export for NetFlow-compatible analytics
- Streaming Telemetry: Real-time counter and state export via gNMI (gRPC) and Arista eAPI (REST). Supports OpenConfig data models for vendor-neutral management.
EOS Automation and Provisioning
The 7280CR3-36S-F 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 and RESTCONF: RESTful and NETCONF programmatic interfaces 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.
Physical Specifications and Airflow
The “-F” airflow configuration provides front-to-rear (forward) cooling, where cool air enters from the non-port side and exhausts from the port side. The compact 1RU form factor enables space-efficient deployment in constrained rack environments. Both -F and -R (rear-to-front) variants are electrically identical.
- Form Factor: 1RU — compact design for flexible deployment
- Power Supply: Dual hot-swappable PSU (1+1) redundancy for high availability
- Cooling: 3-fan architecture with N+1 redundancy and hot-swappable fan trays
- Storage: 4 GB Flash, optional SSD, 2 × USB ports
- Compliance: FCC Class A, CE, RoHS, WEEE
Scalability and Table Sizes
- MAC Addresses: 384K
- IPv4 Unicast LPM Routes: Over 2M
- IPv6 Unicast LPM Routes: 1.4M+ (FlexRoute)
- Algorithmic ACL Entries: 100K+
- ECMP: 512-way
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.
Similar Arista Models to Consider
- DCS-7280CR3K-32P4-F: 32×QSFP28 + 4×OSFP with 4.8 Tbps third-generation K-series for ultra-high-density spine/core deployments.
- DCS-7280CR3K-96-F: 96×QSFP28 with 9.6 Tbps K-series capacity for maximum port density in cloud-scale deployments.
- DCS-7280SR3-40YC6-F: 40×25G + 6×100G with 800 Gbps for access-tier deployments with mixed-speed requirements.
Related 7280 Series Resources
For comprehensive technical documentation and comparative model information across the Arista 7280 family, visit Arista 7280 Series Overview.
Summary
The Arista DCS-7280CR3-36S-F is a compact 1RU switch router combining 36 × QSFP28 multi-speed ports with 2.4 Tbps non-blocking throughput, 4 GB packet buffer, and industry-leading Layer 2/3 capabilities including BGP, MPLS, SR-TE, EVPN, VXLAN, and 512-way ECMP. With support for precision timing (PTP, SyncE, G.8275), comprehensive telemetry (LANZ, sFlow, AEM, DANZ, INT, IPFIX), and full Arista EOS automation (CloudVision, ZTP, eAPI, gNMI), the 7280CR3-36S-F is available from BrightStar Systems fully tested, reset to factory defaults, and backed by a 1-year in-house warranty.
Related Arista 7280 Series models: DCS-7280SR-48C6-R and DCS-7280SR-48C6-F.
