Budget 10G link on Intel X520-DA2: recoding a DAC for Intel on one end and HP on the other
2
The poster wanted a cheap 10G link between servers with Intel X520-DA2 NICs and an HP switch and worried that a direct-attach cable is coded either for Intel or for HP but not both. A respondent shared that two X520-DA2 cards would not link directly over a DAC in their case, but a Dell DAC reprogrammed with Intel coding on one end and Brocade coding on the other came up immediately between an Intel NIC and a Brocade card. The poster then asked how to flash the cable, where to get images and which programmer supports SFP+. A side discussion covered a Brocade SFP+ with RX power around 340 uW that only linked when the LC connector was pulled slightly out, suspected to be an overly strong signal or a bad connector.
- Hardware: Intel X520-DA2, Brocade 10G NIC, HP switch, Brocade switch
- Transceivers: Dell SFP+ DAC, SNR-SFP+DA, Brocade 57-0000075-01 10G SR
- Form factor: SFP+, DAC
Symptoms / messages:
DAC coded for one vendor only
no link between two X520-DA2 direct
link only with LC connector partially unplugged
RX power too high
Comments 2
Flash one end of the DAC with Intel coding and the other with the switch vendor coding; the respondent used a Triton programmer with home-made SFP sockets. Alternatively buy a cable from a supplier that will recode it for you.
For the too-strong-signal case, add attenuation (wrapping the fibre a few turns around a pencil was suggested) or check the DDM power readings and replace the patch cord; with a 170 m multimode run the more likely cause was a bad connector.