Arista 7368X4 Series: 100G, 200G and 400G Hardware in 4RU

The nearest 400G switch Townsend lists is the Arista DCS-7060DX4-32-F, and Arista's own data sheet for the 7368X4 says the two share "a consistent architecture". The 7368X4 itself is a modular chassis, not a fixed switch. It is a 4RU box with eight interface module slots, one supervisor and one switch card, built around a single 12.8 Tbps packet processor. Depending on the modules fitted it holds up to 128 ports of 100G, 32 ports of 400G or 128 ports of 25G.

This page reads those figures from the data sheet, shows how the modules add up to the port counts, and sets the chassis next to the 400G and 800G switches that are listed today. Source for every 7368X4 figure: the Arista 7368X4 data sheet.

What the data sheet gives for the chassis

Arista's part number for the empty chassis is DCS-7368-CH, and the switch card is DCS-7368X4-SC-F or DCS-7368X4-SC-R, where the letter is the airflow. The switch card, power supplies and fans are removed from the rear, so replacing one does not disturb the interface modules or the cabling on the front.

The interface modules and the port counts

The data sheet lists four module types for the eight slots, and says modules can be mixed in one chassis.

The arithmetic is simple. Eight slots of 16 ports is 128 ports of 100G or 128 ports of 25G. Eight slots of four ports is 32 ports of 400G. A chassis can also be part way between: a few 400G modules for uplinks and the rest 100G or 25G modules for servers. Arista also lists a DCS-7358-16C module with 16 ports of 100G that fits the 7358X and 7368X series.

Next to the 400G and 800G switches Townsend lists

A fixed switch is simpler to rack and to spare. A modular one lets the port speeds change without replacing the chassis. The listed switches below come from their own Arista data sheets: 7060X4, 7060X5 and 7280R3. Capacity figures are left out of the table because Arista prints some one way and some both ways.

The 7280R3 row is the odd one out on purpose: it is a switch router, its packet buffer is counted in gigabytes (8 GB on this model) and its latency is higher. If the job is a routed edge or a data center interconnect with large tables, read the Arista 7050X3 and 7280R3 families page. If the job is a leaf or spine at 400G, the 7060 and 7368 rows are the comparison.

Common questions

Does Townsend list the 7368X4? No 7368X4 page is on this site at the time of writing. Listings change, so if you need a chassis, a switch card or a module, send the Arista part number through the quote form and the warehouse is checked.

How many 400G ports can one chassis hold? Up to 32, using eight modules of four ports each, either DCS-7368-4D with QSFP-DD or DCS-7368-4P with OSFP, according to the data sheet.

Can one chassis mix port speeds? Yes. Arista lists the interface modules as mix and match, with 25G, 100G, 200G and 400G options, and each module supports a range of speeds on standard optics and cables.

Which airflow letter do I need? Match the whole chassis. The switch card, power supplies and fan modules each come in a front-to-rear and a rear-to-front version, and the letter is at the end of the part number. The airflow suffix guide explains how Arista's letters compare with Juniper's.

Where to look next

See the Arista 7060X page for the 400G and 800G fixed switches, the Arista 7280R3 page for the 400G routers, and the full Arista switch range. Every unit we ship is tested in-house first and carries our warranty. For retired chassis or modules that you want to move on, send us the list.