Arista DCS-7050Q-16 transceiver compatibility

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im2geek4you

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Feb 27, 2017
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Hi,

Just bought an Arista DCS-7050Q-16 switch on ebay and wanted to know if anyone has one of this working with Brocade 10GbE SFP+ transceivers (PN: 57-0000075-01)?
Also can anyone recomend 1M long compatible QSFP+ cables to work with Mellanox MCX354A-FCBT cards?
 

i386

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Mar 18, 2016
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Every transceiver should work after running "touch /mnt/flash/enable3px" in bash.

For the fdr cards I would try to get fdr14 cable (there were a bunch of ibm branded mellanox cables "cheap" on ebay, ~$20 for 1m, $30 3m) in case that you want to try fdr infiniband or 56gbe on a mellanox switch :D.
 

oddball

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May 18, 2018
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The command i386 mentioned will work in EOS 4.14 and earlier.

This switch will run EOS 4.18 without a problem, but that's as far as it goes.

If you want a newer version of EOS you can pick up optics at FS.com reasonably cheap. Arista supports any DAC regardless of EOS version. Our switches are in the same rack as the servers so we just use DAC's, some Arista, some Cisco, no issues with Cisco, or Mellanox cards.
 

Jerry Renwick

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Aug 7, 2014
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Haven't used Brocade but ordered some QSFP+ DAC cables from FS.COM to connect all our switches (Cisco Nexus 9000 N9K-M6PQ-E). We had no hassle in terms of achieving speed and performance for the Mellanox and Net-gear/CISCO 40G Ethernet switches etc.
 

Foray

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May 22, 2016
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We already covered this in a previous thread, there exists a command ("service unsupported-transceiver") to allow unsupported transceivers. It requires a specific input but its not bound to any serial or hardware, just the nonce and code, which should be able to be found with a simple search.
 

im2geek4you

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Feb 27, 2017
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Finally I got the switch and after some time playing with it here are my findings.
It came with EOS version 4.12.7.1 and had no configuration on it. By default it did not detect any transceiver nor DAC cable. After running "touch /mnt/flash/enable3px" in bash it detectec my generic amphenol made DAC cables as well as my Brocade 10GbE SFP+ transceivers (PN: 57-0000075-01). It did not detect some chinese 10Gtek SFP+ that I have, not sure why...

The swicth power consumption at 230V is around 130W with 5 DAC's and 4 SFP+ with just one power supply on (it draws 108W with just one DAC).
The serial console is easy to access (cisco compatible cables seem to work without problems). The switch is fairly easy to configure. There are plenty of documentation online.

The only bad thing I have to say for this switch is the noise. Damm this thing is loud as hell. It's way much louder than my Quanta LB6M! Using the command to spin down the fans seems to help just a bit (but it seems not to change power supply fan). Anyway it's summer time where I live and it's hot. The fans spin at 66% speed and go up to 75% after a few hours. Temperatures in the switch are around 26 to 38ºC. Replacing fans doesn't seem a very viable option to me unless the heatinks inside the switch could be replaced too to help using lower speed/CFM fans. Because the stock fans are very high CFM fans and I don't want to run it at high temperatures.

Still have to test some things, like the hability to run RJ45 1GBE SFP transceiver/adapters. At least acording to some documentation it seems possible.
 

im2geek4you

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Feb 27, 2017
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So I've been playing with the fan settings and this baby handles the fans at 30% without any problem. Temperatures are between 28 and 42ºC idling. And the noise is a LOT less. Wow.. Also the power draw is a bit less.

Anyway, going back to the subject... Bought a few QSFP+ cables and a RJ45 1GBe SFP transceiver from FS.com. The 1GbE SFP transceiver works a treat :)

Unfortunatelly the QSFP+ cables I got from FS didn't work so well. I bought two 1m long FS branded cables and two 0.5m long, also FS branded cables. For some weird reason the 1m long cables work fine, but the 0.5m just don't o_O
Opened a ticket on FS site complaining about it. Using the same exact settings (same switch, same ports , same nic) 1m cable works and 0.5m doesn't. There is nothing on the website stating the cables are different apart from the lenght. Ironically the first response I got was saying that the 1m long cable is 40G to 10G and the 0.5m is 40G to 40G o_O. I have forced all ports to full 40G on the switch. But even if I set them to other configurations, the 0.5m cable just won't get detected at all. So right now I'm waiting for another answer from their technical support, after sending them some pictures and my running config. At least their support seems willing to help. As last resource I might have to buy 1m cables, which will ruin my cable management :D
 

i386

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Mar 18, 2016
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What happens when you run ""touch /mnt/flash/enable3px"" and restart the switch?
 

im2geek4you

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Feb 27, 2017
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When I did it the first time it continued to detect the cables/qsfp. Didn't went back to check if the file remains in the filesystem, but my guess is that it does. Otherwise a write command probably may have had save that along with the running config.
When I bought it it came factory reseted to defaults. Not sure if I just did the touch comand and restarted the switch without writing a running config it would save that. I would have to reset the switch to default to find out.
 

oddball

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May 18, 2018
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Depending on the version it might not work. That "feature" stopped working on EOS 4.14 or so.

Google "site:eos.arista.com service unsupported-transceiver", pick through the config that comes up, that should work.

My guess is this is something different. You are talking QSFP DAC's right? Arista will take ANY DAC, regardless of brand or coding.
 

im2geek4you

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Feb 27, 2017
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Mine came with version 4.12.7.1. So the enable3px file works fine. Just checked and it is always present even after power cycling the switch.

The one thing that does not stays after power cycle is the damn fan speed setting (environment fan-speed override 30). It is stored in the running config, and after power cycling the switch, the fans report the requested percentage with "show environment all" command (30%), but the fans run way faster. I need to configure them again. That is very annoying :mad:

Anyway, when I got the switch the QSFP DACs were detected as unsuported. I remember I got a message on the console stating the cable was unsuported when I pluged one (cant remember the exact message). Only after creating the enable3px file they started working.
But this 0.5m cable does not even get's detected. It's like there is nothing connected (shows as "not present").
But anyway I tried to run the command you recomended, and got the same result. The transceiver is always in "Not present state". This is what I get on the console:

localhost(config)#show interface ethernet 9/1-4 status
Port Name Status Vlan Duplex Speed Type
Et9/1 notconnect 1 full 40G Not Present
Et9/2 notconnect 1 unconf unconf Not Present
Et9/3 notconnect 1 unconf unconf Not Present
Et9/4 notconnect 1 unconf unconf Not Present
localhost(config)#show interface ethernet 9/1-4 transceiver
If device is externally calibrated, only calibrated values are printed.
N/A: not applicable, Tx: transmit, Rx: receive.
mA: milliamperes, dBm: decibels (milliwatts).
Bias Optical Optical
Temp Voltage Current Tx Power Rx Power Last Update
Port (Celsius) (Volts) (mA) (dBm) (dBm) (Date Time)
----- --------- -------- -------- -------- -------- -------------------
Et9/1 N/A N/A N/A N/A N/A N/A
Et9/2 N/A N/A N/A N/A N/A N/A
Et9/3 N/A N/A N/A N/A N/A N/A
Et9/4 N/A N/A N/A N/A N/A N/A
localhost(config)#show interface ethernet 9/1-4 phy
Key:
U = Link up
D = Link down
R = RX Fault
T = TX Fault
B = High BER
L = No Block Lock
A = No XAUI Lane Alignment
0123 = No XAUI lane sync in lane N

State Reset
Port PHY state Changes Count PMA/PMD PCS XAUI
-------------- --------------- -------- -------- ------- ----- --------
Ethernet9/1 detectingXcvr 2 0 D..A0123
Ethernet9/2 linkDown 2 0 DR. D..A0123
Ethernet9/3 linkDown 2 0 DR. D..A0123
Ethernet9/4 linkDown 2 0 DR. D..A0123
localhost(config)#


The only weird thing I see is the "detectingXcvr" state on the physical info. Not sure what it means.
Just for comparison the 1m cable, this is what I get on the 1m QSFP DAC cables:

localhost(config)#show interface ethernet 5/1-4 status
Port Name Status Vlan Duplex Speed Type
Et5/1 connected 1 full 40G 40GBASE-CR4
Et5/2 errdisabled 1 unconf unconf 40GBASE-CR4
Et5/3 errdisabled 1 unconf unconf 40GBASE-CR4
Et5/4 errdisabled 1 unconf unconf 40GBASE-CR4
localhost(config)#show interface ethernet 5/1-4 transceiver
If device is externally calibrated, only calibrated values are printed.
N/A: not applicable, Tx: transmit, Rx: receive.
mA: milliamperes, dBm: decibels (milliwatts).
Bias Optical Optical
Temp Voltage Current Tx Power Rx Power Last Update
Port (Celsius) (Volts) (mA) (dBm) (dBm) (Date Time)
----- --------- -------- -------- -------- -------- -------------------
Et5/1 N/A N/A N/A N/A N/A N/A
Et5/2 N/A N/A N/A N/A N/A N/A
Et5/3 N/A N/A N/A N/A N/A N/A
Et5/4 N/A N/A N/A N/A N/A N/A
localhost(config)#show interface ethernet 5/1-4 phy
Key:
U = Link up
D = Link down
R = RX Fault
T = TX Fault
B = High BER
L = No Block Lock
A = No XAUI Lane Alignment
0123 = No XAUI lane sync in lane N

State Reset
Port PHY state Changes Count PMA/PMD PCS XAUI
-------------- --------------- -------- -------- ------- ----- --------
Ethernet5/1 linkUp 3 0 U.. D..A0123
Ethernet5/2 linkUp 3 0 U.. D..A0123
Ethernet5/3 linkUp 3 0 U.. D..A0123
Ethernet5/4 linkUp 3 0 U.. D..A0123
localhost(config)#

Can't find any explanation for the 0.5m cables not to work :(
 

im2geek4you

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Feb 27, 2017
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Looks like the fan speeds do actually work after power cycling the switch. They just take a minute to slow down.

- EDIT-
Nop.. after leaving the switch off for one day, and them powering it on again, it ignores the fan settings and slows down for a bit, then goes back up to "normal jet speeds". I need to configure it to auto and then back to forced mode... super annoying...:mad:
 
Last edited:

oddball

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May 18, 2018
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I had a few bad DAC's from FS.com. I emailed them and they RMA'ed them right away. They paid shipping as well.

They can send you replacements, or you can get a refund. Very easy process.

I've had no link detected when the port settings weren't the same on either side. What are your port settings for both ports that are connected?

Here's another test. On the switch, on two unconfigured ports if you plug the cable into itself does it light up and bring up a link?
 

im2geek4you

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Feb 27, 2017
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I tried that. Plugged both ends of the cable on the switch. With 1m cable I get link and with "show inventory" command I see this:

...
System has 24 transceiver slots
Port Manufacturer Model Serial Number Rev
---- ---------------- ---------------- ---------------- ----
1 Fiberstore QSFP-40G-DAC G9999999999-2 03
2 Fiberstore QSFP-40G-DAC G9999999999-1 03
...

with the 0.5m cable I get this:
...
System has 24 transceiver slots
Port Manufacturer Model Serial Number Rev
---- ---------------- ---------------- ---------------- ----
1 Not Present
2 Not Present
...

PS: edited the output and removed the serial number.

I'm not very pleased so far with their technical support. They don't seem to believe that the cables don't work at all, and keep asking for more information. I already sent them a bunch of configuration logs of this, but this time I asked to ship the cables back and get a refund or a replacement for 1m cables that actually work well.
Should have bought the dam cables on eBay. All my eBay cables work! :D
 

im2geek4you

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Feb 27, 2017
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I shipped the 0.5m cables back to them I received a couple of 1m ones a few days ago. These ones work fine.
 

yk644

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Mar 5, 2020
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im2geek4you

I'm in the same situation where cables purchased from fs.com did not link when used to connect to mellanox NIC and Arista 7050T, and there is no link even when both ends of the cable are inserted to the 40Gbe port of Arista.

Can you tell me the exact cable (model#, url etc) you purchased that worked so that I can give it a try?




I shipped the 0.5m cables back to them I received a couple of 1m ones a few days ago. These ones work fine.
 

Foray

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May 22, 2016
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I had some monoprice 40g to 4x10g DAC squid cables that would do the same thing. No logs, no alerts, no link, just nothing. Never figured out why.
 

i386

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@yk644
Did you check how the qsfp+ port is configured?
And before that did you use the command for enabling third party transceivers?

I had to change the configuration from 4x 10 to 1x 40 on my 7050q-16 in eos to work with the qsfp+ cables I had lying around.