Arista Direct Attach Copper (DAC) Cables - Refurbished, Used, New

Best Selling

Arista direct attach copper (DAC) cables are twinax cables with the transceiver ends built in, used to link Arista switch ports to servers, storage and other switches inside a rack or between adjacent racks. They replace two optics and a fiber patch lead with one cable, draw almost no power and add no measurable latency, which is why they are the default choice for top-of-rack and leaf-to-server links. This collection covers Arista straight DACs at 10G, 25G, 40G, 100G and 400G, plus 100G to 4x 25G breakout DACs. NetworkTigers sells them refurbished, used and new, and every cable is tested before it ships.

Arista DAC cables by speed

Part-number family	Speed, connectors and lengths on this page	Shop
CAB-SFP-SFP-xM	10G SFP+ to SFP+, 0.5m, 1m, 1.5m, 2m, 2.5m, 3m, 5m and 7m	0.5m \| 1m \| 2m \| 3m \| 5m \| 7m
CAB-S-S-25G-xM	25G SFP28 to SFP28, 1m, 2m, 3m, 4m and 5m	1m \| 2m \| 3m \| 4m \| 5m
CAB-Q-Q-xM	40G QSFP+ to QSFP+, 0.5m, 1m, 2m, 3m, 5m and 7m	0.5m \| 1m \| 2m \| 3m \| 5m \| 7m
CAB-Q-Q-100G-xM	100G QSFP28 to QSFP28, 0.5m, 1m, 2m, 3m and 5m	0.5m \| 1m \| 2m \| 3m \| 5m
CAB-D-D-400G-xM	400G QSFP-DD to QSFP-DD, 1m	1m
CAB-Q-4S-100G-xM breakout	One 100G QSFP28 port to four 25G SFP28 ends, 1m, 2m, 3m and 5m	1m \| 2m \| 3m \| 5m
Related Arista	Optics and cables for the same switch ports	Arista optics hub \| AOC cables \| Breakout cables \| 10G SFP+ \| All Arista

Which Arista DAC do I need?

Match the cable family to the port on both ends: SFP+ for 10G, SFP28 for 25G, QSFP+ for 40G, QSFP28 for 100G and QSFP-DD for 400G. A 25G cable in a port that only runs 10G will usually negotiate down, but a 10G cable will not run at 25G. Then measure the routed path, including the loop through the cable manager, and pick the next length up; a cable that is too short cannot be fixed. Passive copper reach falls as the speed rises, so the longest lengths in the 40G and 100G families sit at the edge of what some ports support, and your switch's supported-cable list is the final word. For runs past the longest DAC in a family, move to an active optical cable or to transceivers and fiber. Use the breakout family when a 100G leaf port needs to feed four 25G servers.

Frequently asked questions

Will an Arista DAC work between an Arista switch and a non-Arista server adapter?
In most cases yes. DACs follow the SFF standards, and server NICs rarely check the vendor code on the cable. The Arista switch end sees the Arista code it expects, which is the side that matters for a clean link and for avoiding unsupported-transceiver warnings in EOS.

Is there a difference between a used and a new DAC in service?
No, once it passes test. A DAC has no moving parts and no laser to age. The things that fail are bent or crushed twinax and damaged latches, and both are checked before a cable ships.

Can I use a breakout cable in reverse, four 25G switch ports into one 100G server port?
No. The QSFP28 end must sit in a switch port that is configured to split into four lanes. The four SFP28 ends go to the server or downstream switch ports.

NetworkTigers has sold enterprise network equipment since 1996. Every cable carries the NetworkTigers 365-day warranty. Need a length or quantity that is not listed? Ask us for a quote.