Virtual Chassis with 4 x 6860E-24


I have upcoming installation as per the attached diagram. I have following queries for that.

1. How shall I setup a virtual chassis with 4 units of OS6860E-24?

a. by daisy chaining 2 dedicated qsfp vc ports with (4 x DAC cables)

b. by connecting any to any mesh (POD) using sfp+ ports (6 x FC cables)

2. Will the VC setup automatically by default?

3. If both 1a and 1b are workable model, what are the difference of the two designs?





The OS6860 family of switches have dedicated VFL ports for VC purposes, each OS6860E-24 unit comes with two built-in VFL ports, described as "20G Virtual Chassis link ports". Please refer to chapter 13 of Switch Management User Guide for all the details on the configuration options. But this is mostly automatic, once you connect the dedicated DACs (available in different lengths up to 3 meters) the VC services are created automatically. For instance, the 3 meter part number is OS6860-CBL-300, described as a '20 Gigabit direct attached stacking copper cable 3m, QSFP+'.

If you want to build a remote VC, then the 10G SFP+ ports can be used to reach longer distances via fiber cables; for example, the following verbiage comes from chapter 13, "Long distance VFL connections can be configured on the 10G SFP+ ports to extend the capability of the virtual chassis to remote locations".

Please review ch. 13 in the Switch Management Guide (current version = os8_sw_87R3-revA) for configuration options via the automated options using the dedicated VFL ports via DACs, or remotely via manual configuration with connectivity through 10G SFP+ transceivers and fiber optic cabling.

You create VCs of up to 6 units per VC from the same switch family.

--Felipe Soriano


Thanks for the clarifications.

The switch management document explained mainly about virtual chassis by daisy chaining the VFL ports.

I'd also like to learn about setting up the PODs with any to any mesh connections. Could you refer me the appropriate reference document regarding setting up POD topology?


Clarification, a Virtual Chassis (VC) of 6860E’s can contain up to 8 units per VC, I had stated 6 in my original response.

The POD architecture was developed for the OS6900’s that don’t have dedicated VFL ports, where any of the 10G/25G/40G/100G ports can be configured as VFLs. All links configured for VFLs have to be of the same speed for all the VFLs within one VC; a VC can contain up to 6 units. The newer OS6900-V and X48 models only support 100G QSFP28 ports as VFLs. The VFL support is listed in the Specifications Guide under the Virtual Chassis specifications for all OmniSwitch models that support the VC architecture.

Regarding the POD architecture it expands on the VC configuration, and this is explained in detail in the Data Center Switching guide (os8_dc-87r2-revA), chapter 1. For example, it explains that the OS-6900 POD can be used for top-of-rack applications. For example, this configuration can aid in minimizing latency between server hops since they will be interconnected via an OS6900 POD. For example, when one configures a POD of six OS6900’s via 100G VFLs, one would use up to 5 of those ports to form a POD where each OS6900 will connect to the other 5 units via 100G VFLs; thus reducing the server to server hops within a data center.

In answering your direct question, on page 16 of that DC user guide, one can also configure a POD using four 6860E-24’s, where you could build a VC of two 6860E’s and then dual-attach via LACP two additional 6860E’s.

Regarding the MESH options, refer to that same section in the user guide. The Mesh architecture incorporates a VC Core that interconnects multiple PODs.

Hi Timothy,

On the 6860, you can use both the dedicated SFP28 VFL ports or the SFP+ ports. But the topology is always a ring - unlike the 6900 that can work in full and partial mesh topologies as well.

Using the dedicated VFL ports with DAC cables is the preferred option. However, the advantage of using the SFP+ ports is that this enables the creation of a Virtual Chassis in which member units are farther apart because you can use fibre links for interconnection.

The Virtual Chassis is automatically created on bootup if the VFL ports are connected - unless you disable or abort this process. Please refer to the "Switch Management Guide" for further details on automatic virtual chassis configuration.

Hope this helps.