{"id":101695,"date":"2026-09-28T09:53:49","date_gmt":"2026-09-28T09:53:49","guid":{"rendered":"https:\/\/optics.carritech.com\/?p=101695"},"modified":"2026-09-28T10:00:16","modified_gmt":"2026-09-28T10:00:16","slug":"arista-compatible-optics","status":"publish","type":"post","link":"https:\/\/optics.carritech.com\/es\/arista-compatible-optics\/","title":{"rendered":"Arista compatible optics: reading the part numbers and getting the right module"},"content":{"rendered":"

Arista part numbers are unusually readable once you know the pattern \u2014 which is fortunate, because an Arista estate typically spans four generations of platform and five or six optical speeds, and the difference between two similar-looking part numbers is often the thing that decides whether a port comes up.<\/p>\n\n\n\n

This guide covers how Arista optics are named, which form factor belongs to which platform generation, and what a compatible equivalent has to get right. It is the Arista companion to our existing guides for Catalyst 9300 and 9500<\/a>, Nexus 9300<\/a> and the Juniper QFX5120<\/a>.<\/p>\n\n\n\n

How to read an Arista part number<\/h2>\n\n\n\n

Almost every Arista optic follows the same three-part shape: form factor, speed, optical interface<\/strong>.<\/p>\n\n\n\n

\n\n
Prefix<\/th>Factor de forma<\/th>Speeds<\/th><\/tr><\/thead>\n
SFP-<\/code><\/td>SFP, SFP+, SFP28<\/td>100M, 1G, 10G, 25G<\/td><\/tr>\n
QSFP-<\/code><\/td>QSFP+, QSFP28<\/td>40G, 100G, 200G<\/td><\/tr>\n
QDD-<\/code><\/td>QSFP-DD<\/td>200G, 400G, 800G<\/td><\/tr>\n
OSFP-<\/code><\/td>OSFP<\/td>400G, 800G<\/td><\/tr>\n
LPO-<\/code><\/td>Linear pluggable optics<\/td>800G<\/td><\/tr>\n
CAB-<\/code><\/td>DAC and AOC cables<\/td>Todos<\/td><\/tr>\n<\/tbody>\n<\/table><\/figure>\n\n\n\n

The tail of the part number is the optical interface, and it follows the same IEEE 802.3<\/a> conventions as everyone else: SR for short-reach multimode, DR and FR and LR for single-mode at increasing distance, ER and ZR for the long stuff, BD or BIDI for a single-fibre bidirectional pair, and T for copper RJ45.<\/p>\n\n\n\n

Arista then adds qualifiers that catch people out:<\/p>\n\n\n\n