MikroTik CRS310-8G+2S+IN 8×2.5G 2×SFP+ Switch ROS

The MikroTik CRS310-8G+2S+IN is the purpose-built 2.5 Gigabit migration switch for small offices, creative studios, workstation clusters, and home labs that have outgrown Gigabit but are not yet deploying full 10G infrastructure. The 2.5G Ethernet tier — 2.5GBASE-T on standard Cat5e or Cat6 cabling — is the practical upgrade path for existing copper infrastructure where re-cabling to Cat6A for 10GBASE-T is cost-prohibitive or disruptive. The CRS310-8G+2S+IN delivers 2.5G on all eight copper ports over existing cabling, with 10G SFP+ uplinks for backhaul to a 10G-capable core switch or router.

**Why 2.5G now — the migration context**

The 2.5G Ethernet transition is accelerating in 2024–2026 for two converging reasons: Wi-Fi 6 and NVMe-based NAS. Wi-Fi 6 (802.11ax) access points — including MikroTik's own mANTBox ax 15s, hAP ax lite, and hAP ax³ — are capable of aggregate wireless throughput that saturates a Gigabit Ethernet uplink under realistic multi-client load. A Wi-Fi 6 AP connected to a Gigabit switch port becomes the bottleneck in any deployment where multiple Wi-Fi 6 clients are simultaneously transferring at high rates. Connecting that same Wi-Fi 6 AP to a 2.5G switch port removes the wired bottleneck — the AP's 2.5G Ethernet port operates at its intended backhaul capacity. Similarly, NVMe-based NAS devices — Synology, QNAP, and custom builds — now commonly ship with 2.5G or 10G Ethernet ports, and connecting them to a Gigabit switch caps their effective network transfer rate well below the NAS's actual storage throughput. The CRS310-8G+2S+IN's 8× 2.5G ports address both use cases simultaneously.

**2.5GBASE-T on existing Cat5e/Cat6 cabling**

2.5GBASE-T (IEEE 802.3bz) operates on the same copper cabling as Gigabit Ethernet — Cat5e (2.5G) and Cat6 (5G and 2.5G) — at runs up to 100 metres. For a small office or home lab where Gigabit Ethernet cabling was installed during construction or renovation, 2.5G connectivity requires only switch replacement — no re-cabling. This is the CRS310-8G+2S+IN's primary value proposition versus 10GBASE-T: 10GBASE-T requires Cat6A cabling (or Cat6 at reduced distances), creating a cabling retrofit cost that can exceed the switch cost in an existing installation. The CRS310-8G+2S+IN delivers the 2.5G upgrade without a cabling project.

**The Marvell 98DX226S — one chip, switch ASIC and CPU combined**

The Marvell 98DX226S is a unified device: it is simultaneously the switch ASIC and the dual-core ARM32 CPU running RouterOS v7. This integrated architecture — where the switch fabric and the management CPU share a single chip die — is Marvell's approach in the Prestera Lite family, optimised for compact, cost-efficient managed switch products. The 98DX226S provides:

- **Hardware-offloaded Layer 2 switching:** VLAN tagging and filtering, MAC address table forwarding, STP/RSTP, link aggregation (LACP 802.3ad), and QoS queue management — all hardware-offloaded at line rate across all 8× 2.5G ports and 2× SFP+ ports simultaneously.

- **Hardware-offloaded Layer 3 routing:** The 98DX226S supports hardware-offloaded Layer 3 routing — inter-VLAN routing between VLANs defined on the CRS310-8G+2S+IN is performed in the switch ASIC hardware rather than in software on the ARM CPU. MikroTik's own product description explicitly calls out hardware-offloaded Layer-3 routing as a capability. This is a meaningful distinction versus Layer 3 switches that perform inter-VLAN routing in software — hardware-offloaded L3 routing at 2.5G line rate does not consume CPU cycles and does not degrade performance as routing table size or traffic volume increases within the hardware's routing table capacity.

- **ACL packet filtering:** Hardware ACL rules — Layer 2, 3, and 4 packet classification and filtering in the 98DX226S ASIC hardware. ACL rules on the CRS310-8G+2S+IN do not consume CPU bandwidth — they are evaluated in hardware at line rate across all switch ports simultaneously.

- **Jumbo frame support:** Jumbo frames (typically 9,000 byte MTU) reduce CPU overhead and improve throughput efficiency for large data transfers — NAS-to-workstation file transfers, iSCSI storage traffic, and VM live migration traffic between hypervisors. Jumbo frames are particularly relevant for a NAS deployment where the NAS and connected workstations all support jumbo frames and are connected to the CRS310-8G+2S+IN.

**SFP+ multi-rate ports — 1G / 2.5G / 10G flexibility**

The 2× SFP+ ports on the CRS310-8G+2S+IN support multiple data rates: 1G, 2.5G, and 10G. This multi-rate SFP+ capability is a deliberate design choice that significantly expands the CRS310-8G+2S+IN's deployment flexibility:

- **10G SFP+ uplink:** The primary uplink use case — a 10G SFP+ DAC cable or SFP+ transceiver connecting the CRS310-8G+2S+IN to a 10G-capable upstream switch, router, or NAS. For a deployment where the CRS310-8G+2S+IN is the access layer switch and connects via 10G SFP+ uplink to a CRS326-4C+20G+2Q+RM, CRS354, or CCR2004 core router, the 10G SFP+ uplink provides 10 Gbps aggregate backhaul capacity — headroom for all eight 2.5G ports to operate simultaneously without congesting the uplink.

- **2.5G SFP+ operation:** The multi-rate SFP+ ports can operate at 2.5G — effectively extending the CRS310-8G+2S+IN to a 10× 2.5G switch by using both SFP+ ports as 2.5G access ports (with 2.5G-compatible SFP transceivers or DAC cables) rather than 10G uplinks. MikroTik's own product description explicitly states this: "you can use this switch as a 10x 2.5G switch, if needed." For a deployment where 10 × 2.5G access ports are required rather than 8 × 2.5G + 2 × 10G uplink, both SFP+ ports can serve as 2.5G data ports.

- **1G SFP operation:** Standard 1G SFP transceivers or DAC cables operate in the SFP+ ports at 1G — backward compatibility with existing 1G SFP infrastructure. For a deployment where the upstream switch or router has only a 1G SFP uplink port available, the CRS310-8G+2S+IN's SFP+ ports accept the 1G SFP connection without requiring an adapter.

**RouterOS v7 License 5 — the correct licence tier for SMB managed switching**

RouterOS v7 License 5 on the CRS310-8G+2S+IN positions it above the CRS310's License 4 siblings in the MikroTik licence hierarchy. License 5 provides the full RouterOS feature set including unlimited routing protocol instances, MPLS, and advanced queue management — capabilities that are not required for a pure access-layer switch deployment but become relevant when the CRS310-8G+2S+IN is deployed as a combined switch-router at the network edge. For a small office where the CRS310-8G+2S+IN is the only network device — combining switching, routing, NAT, DHCP, firewall, and VPN functions — RouterOS v7 License 5 provides every feature needed without restriction.

The dual-boot RouterOS v7 / SwitchOS architecture allows operator choice of management paradigm. SwitchOS provides a streamlined managed switch interface — VLAN configuration, port mirroring, SNMP, and traffic statistics — without the RouterOS routing and firewall complexity. For a network administrator who wants a managed 2.5G switch with a simple web UI and no RouterOS learning curve, SwitchOS is the correct operating mode. RouterOS v7 is the correct mode for deployments requiring routing, firewall, VPN, or advanced traffic management beyond pure switching.

**USB 2.0 Type-A port (1A, USB Power Reset)**

The USB port on the CRS310-8G+2S+IN provides two functions:

- **USB storage:** A USB flash drive provides local storage for RouterOS configuration backups, syslog archiving, or data files. For a deployment where automated configuration backup to local storage is required, the USB port provides the backup medium without a network NAS or cloud storage dependency.

- **USB Power Reset:** RouterOS's USB Power Reset feature allows a script to power-cycle a device connected to the USB port — for example, a USB LTE modem attached for WAN failover, or a USB-powered device that requires periodic power cycling for reliability. The USB Power Reset function cuts and restores USB port power under RouterOS script or scheduler control.

**Mounting flexibility — desktop, 19" rack, 10" rack**

The CRS310-8G+2S+IN ships with rackmount ears for standard 19" rack installation. The optional RMK-2/10 accessory (sold separately) enables two deployment variants not available on most compact switches:

- **Two CRS310 units in one 1U 19" rack space:** The RMK-2/10 mounts two CRS310-8G+2S+IN units side by side in a single 1U rack space — effectively deploying 16× 2.5G + 4× SFP+ in 1U, a density that no single 1U switch at this price point matches.

- **10" rack mounting:** The CRS310-8G+2S+IN fits in a 10" rack with the RMK-2/10 accessory — relevant for wall-mount cabinet deployments, smaller equipment racks common in retail, hospitality, and office closet installations, and AV equipment racks where 10" rack format is standard. 10" rack mounting at 2.5G is a rare capability in the current managed switch market.

The compact 200 × 206.1 × 44 mm dimensions (approximately 200mm wide, 206mm deep, 44mm height — roughly 1U) and desktop form factor with K-48 fastening set allow surface mounting on a desk, shelf, or inside a cabinet without rack infrastructure.

**Active cooling — single fan**

The CRS310-8G+2S+IN uses a single fan for active cooling — unlike the passive cooling of the CRS304-4XG-IN and other compact MikroTik switches. The fan is required by the combined thermal load of 8× 2.5G PHYs and 2× 10G SFP+ PHYs operating simultaneously. For office deployments where fan noise is a consideration, the CRS310-8G+2S+IN should be evaluated for acoustic impact — fan-cooled switches in a quiet office environment are audible at close range. For rack or closet deployments where fan noise is not a concern, the single fan provides adequate thermal management across the -40°C to +60°C operating temperature range.

**5-year software support guarantee:** RouterOS v7 and SwitchOS updates free for life of product or minimum 5 years from date of purchase.

**Canadian market note:** Certifications are CE, EAC, and RoHS — no FCC or IC (ISED) published. The CRS310-8G+2S+IN is a wired switch with no wireless transmitter. No ISED wireless certification advisory applies. Confirm any applicable Canadian electrical safety certification requirements with your distributor before listing.

Key specifications:

- **Product code:** CRS310-8G+2S+IN

- **Architecture:** ARM 32-bit

- **CPU / Switch ASIC:** Marvell 98DX226S, dual-core ARM32, 800 MHz (integrated)

- **RAM:** 256 MB

- **Storage:** 32 MB FLASH

- **OS:** RouterOS v7 License 5 / SwitchOS (dual-boot)

- **2.5G Ethernet ports:** 8×

- **SFP+ ports:** 2× (multi-rate: 1G / 2.5G / 10G)

- **USB:** 1× USB 2.0 Type-A, 1A, USB Power Reset

- **DC jack input:** 18–57V

- **Max power consumption:** 34W

- **Max power without attachments:** 21W

- **Cooling:** Active (1 fan)

- **IP rating:** IP20

- **Dimensions:** 200 × 206.1 × 44 mm

- **Operating temperature:** -40°C to +60°C

- **MTBF:** ~200,000 hours at 25°C

- **Monitors:** CPU temperature, PCB temperature

- **Certifications:** CE, EAC, RoHS — no FCC, no IC published

- **Included:** 24V 1.5A power adapter, K-48 fastening set, rackmount ears

- **Optional accessory:** RMK-2/10 (dual-unit 1U 19" or 10" rack mount — sold separately)

- **Suggested price:** USD 219.00