Arista DCS-7280CR3-32D4-F — Hybrid 100G/400G Switch Router with 8 GB Buffer and Forward Airflow
The
Arista DCS-7280CR3-32D4-F is a 1RU switch router from the 7280R3 series, combining
32 × 100G QSFP28 access ports with
4 × 400G QSFP-DD uplink ports in a single platform delivering
4.8 Tbps of wire-speed performance and
8 GB of packet buffer. Unlike pure data center switches, the 7280CR3-32D4 is a full switch router — supporting deep L3 routing features including MPLS, Segment Routing, and BGP with large-scale route tables — making it equally at home as a DCI edge router, WAN aggregation node, or high-performance data center spine requiring 400G uplink connectivity. The “
-F” suffix denotes
front-to-rear (forward) airflow, the standard configuration for traditional hot-aisle/cold-aisle data center deployments where cold air is supplied from the front of the rack.
Key Features at a Glance
- 32 × 100GbE QSFP28 access ports — each configurable at 100G, 40G, 4×25G, or 4×10G
- 4 × 400GbE QSFP-DD uplink ports — each breakout-capable to 4×100G for additional port density
- 4.8 Tbps total wire-speed performance across all ports
- 8 GB packet buffer — orders of magnitude deeper than standard switching ASICs for bursty traffic absorption
- Full switch router feature set: MPLS, SR-MPLS, SRv6, BGP, IS-IS, OSPF with large-scale route table support
- Front-to-rear airflow (“-F”) for standard hot-aisle/cold-aisle data center deployments
- Redundant, hot-swappable AC power supplies for continuous availability
- VXLAN, EVPN, MLAG, and advanced L2/L3 fabric features alongside full routing capabilities
- Rich telemetry: LANZ, sFlow, AEM, and streaming telemetry
- Runs Arista EOS® with open APIs, Python/Bash scripting, and CloudVision® integration
The 32D4 Port Layout: 32×100G Access Plus 4×400G Uplinks
The defining architectural characteristic of the
7280CR3-32D4 is its hybrid port configuration — a combination no pure switching ASIC offers in this form factor:
- 32 × 100G QSFP28 ports: High-density access layer connectivity for leaf switches, servers, or storage nodes. Each port is configurable at 100G, 40G, 4×25G, or 4×10G — identical flexibility to the 7060 spine family.
- 4 × 400G QSFP-DD ports: High-bandwidth uplink capacity for DCI circuits, 400G WAN transponders, or super-spine connections. Each 400G port can break out to 4×100G, providing up to 16 additional 100G connections if needed.
This port mix enables a common deployment pattern: use the 32 QSFP28 ports for 100G leaf switch or server connectivity, and use the 4 QSFP-DD ports for 400G DCI links to a second data center or for 400G WAN transport. A single 7280CR3-32D4 can simultaneously serve as a spine switch for a 100G fabric
and as the DCI edge router — eliminating a dedicated edge router tier in many architectures.
8 GB Deep Buffer: Built for Bursty and Long-Distance Traffic
The 7280CR3-32D4’s
8 GB packet buffer is not an incremental improvement over standard switching platforms — it is a categorical difference. Standard data center spine switches such as the 7060CX-32S carry 16 MB of shared buffer; the 7280CR3-32D4 carries 8 GB, which is
500× more buffer capacity. This deep buffer capability matters in several specific scenarios:
- WAN edge and DCI links: Long-distance circuits between data centers experience traffic rate mismatches and bursty patterns as workloads migrate or replicate. Deep buffers absorb these bursts without drops that would trigger TCP retransmission storms.
- Storage traffic consolidation: NVMe-over-Fabrics (NVMe-oF) and parallel storage workloads generate incast patterns that shallow-buffer spine switches struggle to handle. The 8 GB buffer absorbs storage fabric bursts without impacting latency-sensitive compute traffic.
- Speed mismatch ingestion: When traffic arrives at 400G and must be distributed across multiple 100G downlinks, the deep buffer prevents head-of-line blocking and maintains flow integrity during burst events.
- Peering and transit routing: Environments that absorb full or partial internet routing tables benefit from deep buffers that handle transient route flaps and traffic re-convergence without dropping established flows.
Switch Router: Full MPLS, Segment Routing, and BGP
The 7280CR3-32D4 is a
switch router — it combines the forwarding density of a data center switch with the routing depth of a service provider platform. This means it supports the full EOS routing feature set:
- BGP: Full internet routing table support, multi-VRF, route reflector operation, BGP-LU, and BGP-CT for complex peering and transit architectures
- MPLS and RSVP-TE: L3VPN, pseudowire, and MPLS transport for service provider and WAN applications
- Segment Routing (SR-MPLS and SRv6): Traffic-engineered paths for DCI, WAN, and multi-site fabric interconnect without RSVP-TE state overhead
- IS-IS and OSPF: Full link-state routing with TE extensions for complex multi-area topologies
- VXLAN and EVPN: Overlay fabric support for multi-tenant data center and DCI deployments
This routing depth distinguishes the 7280CR3-32D4 from pure switching platforms like the 7060 series, which are optimized for high-speed east-west fabric switching rather than complex L3 routing at the network edge.
Port Density and Optics
The
7280CR3-32D4-F supports a broad range of standards-based
optics and cables:
- QSFP28 (100G): 100GBASE-SR4, LR4, ER4, PSM4; QSFP28 DACs and AOCs for short-reach connections
- QSFP-DD (400G): 400GBASE-SR8, DR4, FR4, LR4; 400G DACs and AOCs for high-bandwidth DCI and WAN connections
- Breakout: Each 400G QSFP-DD port supports 4×100G breakout via MPO fan-out cables
Telemetry and Operational Visibility
The
DCS-7280CR3-32D4-F includes Arista’s full telemetry stack, critical for monitoring complex routing environments:
- LANZ (Latency Analyzer): Real-time per-port queue depth visibility — particularly valuable on the 400G QSFP-DD ports where speed mismatches with downstream 100G links can cause transient buffering
- sFlow: Continuous traffic sampling for flow analysis across both 100G access and 400G uplink ports
- AEM (Arista Event Monitor): Programmable alerting for routing protocol events, BGP prefix changes, MPLS path failures, and buffer threshold crossings
- Streaming Telemetry: gRPC-based high-frequency state export for both switching counters and routing protocol state, enabling comprehensive BGP/IS-IS/MPLS health monitoring
EOS Automation and Extensibility
Running on
Arista EOS®, the
DCS-7280CR3-32D4-F supports automation-first operations for both switching and routing functions:
- Native on-box Python and Bash scripting, including route-map and policy automation
- JSON-RPC eAPI for full BGP, MPLS, and routing table programmatic access — integrates with Ansible, Terraform, and custom tooling
- CloudVision® for centralized configuration management, topology visualization including DCI links, and change control
- OpenConfig and gNMI for model-driven routing configuration and BGP state streaming
- BGP FlowSpec for programmatic traffic engineering and DDoS mitigation at the edge
Front-to-Rear Airflow and Data Center Fit
The “
-F” airflow configuration provides
front-to-rear (forward) cooling, where cool air enters from the non-port side of the switch and exhausts from the port side — the standard configuration for hot-aisle/cold-aisle data center designs.
Security Features
- Secure boot and digitally signed EOS images
- Role-Based Access Control (RBAC) with network operator and read-only role separation
- TACACS+/RADIUS/LDAP for centralized authentication and accounting — critical for edge routers with external-facing BGP sessions
- BGP TTL Security (GTSM) to protect against off-path BGP session hijacking
- Control Plane Policing (CoPP) to protect the routing engine from volumetric control-plane attacks
- ACLs and uRPF for traffic filtering and spoofed-source protection on internet-facing interfaces
Deployment Scenarios and Industry Applications
- Data Center Interconnect (DCI) Router: Use the 4×400G QSFP-DD ports for DCI circuits between facilities while the 32×100G ports serve local fabric or server connectivity — all on a single 1RU platform with full EVPN/VXLAN DCI capability.
- WAN Edge and Internet Peering: Full BGP support with large route table capacity and deep 8 GB buffer for absorbing WAN traffic variability and route convergence events.
- 100G/400G Hybrid Spine: Spine switch that connects 100G leaf switches today while providing 400G uplinks to a next-generation super-spine or DCI fabric — a migration-friendly architecture that avoids forklift upgrades.
- Aggregation and Core Routing: Multi-VRF, MPLS L3VPN, and Segment Routing make the 7280CR3-32D4 a strong fit for service provider and cloud provider aggregation layers with diverse tenant routing requirements.
- Enterprise WAN Hub: Central hub for SD-WAN overlay traffic with full BGP policy control, MPLS transport, and deep buffer for variable WAN link utilization.
- Storage and NVMe-oF Fabric: The 8 GB deep buffer handles the bursty, incast-heavy traffic patterns generated by NVMe-over-Fabrics storage systems — far better than shallow-buffer switching alternatives.
Lifecycle, Reliability, and Future-Proofing
The
7280CR3-32D4-F is built for long operational lifecycles typical of WAN-edge and DCI platforms — environments where hardware longevity and consistent EOS routing feature development are as important as raw performance. The 400G QSFP-DD uplink ports provide a forward-compatible connection fabric as 400G becomes the standard for inter-DC connectivity, while the 100G QSFP28 ports continue to support the installed base of 100G leaf switches and servers for years to come.
Competitive Comparison
- Versus Arista DCS-7060CX2-32S-F: The 7060CX2 offers lower latency (450 ns vs routing-mode latency on the 7280) and higher pure switching density. The 7280CR3-32D4-F adds 400G uplinks, 500× more buffer, and full MPLS/SR routing capabilities — for environments that need a router, not just a switch.
- Versus Cisco ASR 9000: The 7280CR3-32D4-F offers comparable routing capability at a significantly lower power, footprint, and cost profile in 1RU. EOS provides a more automation-friendly environment than IOS-XR.
- Versus Juniper PTX Series: Similar high-performance routing intent; the 7280CR3-32D4-F differentiates on Arista EOS automation depth, LANZ telemetry, and CloudVision integration for data center-edge routing roles.
Similar Arista Models to Consider
- Arista DCS-7280DR3-24-F – Pure 400G switch router with 24×400G QSFP-DD, 9.6 Tbps, and 16 GB ultra-deep buffer (2× this model) for the most demanding storage and DCI workloads.
- Arista DCS-7060CX2-32S-F – 32×100G pure switching spine with 22 MB buffer and 450 ns latency — the right choice when MPLS/SR routing features are not required.
- Arista DCS-7060CX-32S-F – First-generation 32×100G pure switching spine — proven, cost-effective alternative when routing depth and 400G uplinks are not needed.
Related 7280R3 Resources
Best Arista 7280R/7280R2/7280R3 Switches (2025): Model Comparison, Architecture & Deployment Guide
The 100G/400G Switch Router for DCI, WAN Edge, and Deep-Buffer Spine Deployments
The
Arista DCS-7280CR3-32D4-F bridges the gap between data center switching and WAN routing in a single 1RU platform. Its 32×100G + 4×400G hybrid port mix, 8 GB deep buffer, and full MPLS/Segment Routing feature set make it uniquely suited for the DCI edge, WAN aggregation, and spine roles where pure switching platforms fall short. Whether you need 400G DCI uplinks alongside 100G fabric connectivity, full BGP peering with deep buffer to absorb route convergence, or MPLS L3VPN for multi-tenant edge routing — the 7280CR3-32D4-F does it all in a 1RU form factor. Available from BrightStar Systems fully tested, reset to factory defaults, and backed by a 1-year in-house warranty.
Also available: DCS-7280CR3-32D4-R with rear-to-front airflow.
