Dell Networking S6100-ON 100GbE Switch

The Dell Networking S6100-ON is a 2RU modular data centre switch built around four I/O module bays, giving a maximum configuration of 32 ports of 100GbE QSFP28, 64 ports of 40GbE QSFP+, or 128 ports of 25GbE or 10GbE via breakout, plus two fixed SFP+ ports, on a 6.4 Tbps non-blocking fabric.

Almost every other switch in this class has its ports welded to its personality. The S6100-ON does not. The chassis is a fabric and a control plane; what appears on the front panel is whatever four modules you put in it, and it can be changed later.

Four bays, three module types, and why that matters

The 32-port 100GbE figure in this product's name is a maximum configuration, not a fixed port count. It is what you get when all four bays hold 100GbE modules. Dell built three module types for this chassis:

• 16x QSFP+ 40GbE module. All sixteen ports run at 40GbE, and eight of them can break out to 4x 10GbE. Four of these modules gives 64 ports of 40GbE in 2RU.
• 8x QSFP28 100GbE module. Each port runs 100GbE natively, or breaks out to 4x 25GbE, 2x 50GbE or 4x 10GbE. Four of these gives the headline 32x 100GbE.
• 4x CXP + 4x QSFP28 module. Four CXP 100GbE ports alongside four QSFP28 ports, for estates that still have CXP-terminated links to serve.

Mixed configurations are the interesting ones. Two 100GbE modules and two 40GbE modules gives sixteen 100GbE ports for the spine and thirty-two 40GbE ports for the existing estate, in one chassis and one management domain. That is the entire argument for buying a modular switch instead of two fixed ones: it lets a network be halfway through a migration without being halfway through a rack refresh.

Because of that, the module configuration is a real decision on this page rather than an afterthought. Tell us what you need on each bay and we will build it that way.

Fabric, buffer and latency - what 6.4 Tbps actually buys

The switching fabric carries 6.4 Tbps of I/O bandwidth full duplex and forwards up to 4,400 Mpps, which is line rate across every port in every module combination the chassis accepts. There is no oversubscription to design around: the fabric was sized for the maximum-density configuration, so a partially-populated chassis is simply running below its ceiling.

Latency is 300 ns at Layer 2 and 400 ns at Layer 3. The packet buffer is 16MB - modest by current standards, and the honest limitation of this generation. It is ample for a top-of-rack or aggregation role with well-behaved traffic; it is not the switch to put at a severe incast point where many-to-one flows collide at line rate. If your workload is bulk storage replication or a large map-reduce shuffle, size the buffer question before the port question.

Table scale is generous for the class: 160K MAC addresses, 128K IPv4 unicast routes with a 128K ARP table, 64K IPv6 unicast routes, 64K IPv4 and 32K IPv6 multicast routes, 4K VLANs per port, and 128 LAG groups of up to sixteen members each with enhanced hashing.

ONIE, Dell Networking OS, and the licensing question

The "-ON" suffix means open networking. The switch ships with the Open Network Install Environment, a bootloader whose only job is to fetch and install a network operating system. Dell Networking OS is the native choice and is where the L3 feature licence lives; the same ONIE bootloader will install alternative ONIE-compatible network operating systems instead.

For a second-hand buyer this is the difference between owning hardware and renting a platform. What arrives is the chassis, the modules and the fabric. What runs on it is a separate decision, and an L3 licence is a line item rather than a lock-in. Expect the unit to need an OS install on arrival; a switch sitting at the ONIE prompt is in the state Dell designed, not a fault.

Dell's Open Automation Framework sits above that - a set of interoperating tools for automated configuration and provisioning that were aimed at virtualised data centre environments. VXLAN Layer 2 gateway support connects hypervisor overlay networks to non-virtualised infrastructure, VRF-lite gives Layer 3 tenant isolation across shared infrastructure, and OpenFlow 1.3 is supported for controller-driven fabrics.

Redundancy, airflow and the two orderable builds

Two hot-swappable power supplies with integrated fans sit alongside five hot-swappable fan subsystems. Both AC and DC supplies exist. Maximum consumption is 750W with a 350W typical figure, from a 100-240 VAC 50/60 Hz input, and the chassis is Dell Fresh Air compliant to 45 C.

Airflow direction is a build-time choice and it is expressed in Dell's own product numbers: 210-AFRS is the normal-airflow base unit, drawing air from the I/O panel toward the power supplies, and 210-AFRR is the reverse-airflow build. Changing direction later is possible but requires the unit powered down and every fan and power supply unit swapped for matching-direction parts. The direction you want depends on which aisle your port face looks into: ports in the cold aisle means normal airflow, ports in the hot aisle means reverse.

Rack mounting uses the tool-less ReadyRails system. Dell also produced MTP-to-LC cable breakout kits specifically for this chassis, in 1RU 64-port and 48-port variants over multimode or single-mode fibre - worth knowing about, because a fully-populated S6100-ON generates a lot of fibre to dress.

Where it sits in the Dell 100GbE line

The S6100-ON and the Z9100-ON reach the same 32-port 100GbE headline number from opposite directions. The Z9100-ON is 1RU with 32 fixed QSFP28 cages - simpler, denser per rack unit, and the better spine when every port is the same speed. The S6100-ON is 2RU and modular - the better choice when the port mix is not uniform, when 40GbE and 100GbE have to coexist behind one management address, or when the port configuration needs to survive a change of plan.

Above both, Z9264F-ON doubles fixed 100GbE density to 64 ports, and the Z9432F-ON moves the fabric to 400GbE. Below, the S-Series 1/10/40GbE top-of-rack switches are what the S6100-ON was designed to aggregate.

Every unit is professionally reconditioned, fully tested and shipped with warranty. Tell us the module configuration and airflow direction you need and we will quote the exact build.

Specifications