Brocade “compatible” SFP’s will disrupt your fabric.

As with all good stuff there are always people and companies that try to jump on the bandwagon and make some dollars by using cheap kit and sell it as “Original” or “Compatible” or “Vendor equivalent”. Don’t fall for this trap and simply buy Original Vendor Branded & Supported equipment. One example is FiberStore.

Recently I ran into a case where a customer had purchased a batch of long wave 8G SFP’s  in order to “upgrade” from 4G and tried to move a heavy replication load over it. When looking at the error counters on 4G speed with original Brocade SFP’s there was no problem at all. As soon as the 8G SFP’s were used the encoding and crc errors were ramping up significantly. This isn’t the first time I see this happening and most often it is the lack of cable quality that is detrimental to the link power-budget and causes these issues. The cable was tested and the OTDR trace did not indicate any issue end-to-end on that speed. This led me to check the values on the SFP’s and to my astonishment I saw that these were non-brocade branded ones. As you may know Brocade disables any SFP unless it is not “Brocade branded”. This is simply done by looking at the OUI that is burned into the ROM of the SFP. It looks like this:

SW01:FID128:admin> sfpshow 2/1
Identifier:  3    SFP
Connector:   7    LC
Transceiver: 700c406000000000 4,8,16_Gbps M5,M6 sw Inter,Short_dist
Encoding:    6    64B66B
Baud Rate:   140  (units 100 megabaud)
Length 9u:   0    (units km)
Length 9u:   0    (units 100 meters)
Length 50u (OM2):  4    (units 10 meters)
Length 50u (OM3):  0    (units 10 meters)
Length 62.5u:2    (units 10 meters)
Length Cu:   0    (units 1 meter)
Vendor Name: BROCADE
Vendor OUI:  00:05:1e
Vendor PN:   57-0000088-01
Vendor Rev:  A

It turns out that FOS just checks on the Vendor OUI part for deciding to turn it on or not. The SFP’s the customer bought showed this:

=============
Port 23:
=============
Identifier:  3    SFP
Connector:   7    LC
Transceiver: 5401001200000000 2,4,8_Gbps SM lw Long_dist
Encoding:    1    8B10B
Baud Rate:   85   (units 100 megabaud)
Length 9u:   10   (units km)
Length 9u:   100  (units 100 meters)
Length 50u (OM2):  0    (units 10 meters)
Length 50u (OM3):  0    (units 10 meters)
Length 62.5u:0    (units 10 meters)
Length Cu:   0    (units 1 meter)
Vendor Name: FIBERSTORE
Vendor OUI:  00:05:1e
Vendor PN:   CSFP+-8G51-10-BR
Vendor Rev:  A
Wavelength:  1510 (units nm)

You can see the OUI is the same but it is officially registered to Brocade and not FiberStore. This show a serious lack of ethics and is plain theft as far as I’m concerned. It is like having a “Rolex” watch showing “Made in China” and a $20.00 price-tag. As always, if it looks to good to be true it often is.

As FOS will simply check on the OUI the SFP is not disabled as it would do with other OUI’s.

Both Brocade and Cisco maintain a rigorous qualification matrix when it comes to SFP’s. As they are such an integral part of the entire physical infrastructure do NOT try to bypass these matrices as sooner or later it will come back to you big time. Do not expect any support from either Brocade, Cisco or one of their OEM’s when these kind of non-qualified SFP’s are seen in the switches.

I wouldn’t be surprised if Brocade and Cisco sooner or later will put some more checks in their firmware in order to prevent this from becoming a massive problem. Some sort of other certificate verification based on the combination of attributes in those SFP’s would seen logical. As long as the complexity is 100% hidden from an administrator I wouldn’t mind. Another problem less to worry about.

Hope this helps,

Kind regards,

Erwin

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About Erwin van Londen

Master Technical Analyst at Hitachi Data Systems
Brocade, Config Guide, Troubleshooting , , , , ,