Can I connect server to CX-4 on back of D-Link DGS-3420 switch?

Discussion in 'Networking' started by AveryFreeman, Jul 2, 2018.

  1. AveryFreeman

    AveryFreeman ESXi + ( BSD / ZFS ) = HAPPY

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    Hi,

    I was just wondering if it's possible to connect a server directly to the back of a DGS-3420 switch, it has two CX-4 connectors on the back that I know can be used for stacking switches together, but I wasn't sure if it could also be used for server connectivity.

    If anyone has any experience with these switches and doing this sort of thing I'd appreciate their feedback. I have absolutely 0% experience with any 10G+ networks.

    Thanks!
     
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  2. Zuhkov

    Zuhkov New Member

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    Not familiar with that particular switch, but I did exactly this with an LB4 switch that has 4 CX-4 ports. Used Myricom 10G cards and DACs to connect them to the switch. Eventually moved to a newer switch with SFP+ due to the noise, but it worked quite well for several years. Critical question is whether the DGS-3420 supports the use of those ports for that purpose.

    Edit: if this describes the module you have, it would appear the answer is yes, you can connect servers to the switch via these ports: ftp://ftp.dlinkla.com/pub/DEM-420CX/DATASHEET-DEM-410420CX_02.pdf
     
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    Last edited: Jul 2, 2018
  3. fohdeesha

    fohdeesha Active Member

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  4. AveryFreeman

    AveryFreeman ESXi + ( BSD / ZFS ) = HAPPY

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    Hmmm... cool. But then, I want to go from Firewall/Gateway w/ Chelsio S310E-CXA --->> DGS-3427 10GbE Uplink #1 --->> DGS-3427 10GbE Uplink #2 --->> CX-4 to SFP+ cable --->> ProSafe XS708E 10GbE SFP+ Uplink --->> 10GBase-T Clients

    Does that setup make sense?
     
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  5. fohdeesha

    fohdeesha Active Member

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    If you can find a cx4 to SFP+ cable for not a bajillion dollars, sure. They tend to be a little costly though as they're "specialty items" in my experience
     
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  6. AveryFreeman

    AveryFreeman ESXi + ( BSD / ZFS ) = HAPPY

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    I found one for $50 here:

    CX4 with Ejectors to SFP+ | DataStorageCables

    But I have no idea if it's electrically compatible. For all I know it just has the right ends.

    After seeing all these specialty 'media converter' devices that sell for hundreds of dollars, I'm experiencing a little PTSD.

    I'll email them and see what they say...

    The other option is CX-4 to 10Gbase-T (RJ45) ... but must chain using ASIC devices.

    The internets tell me my original idea of having a gateway server bridging both SFP+ and CX-4 would be slow AF.
     
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  7. fohdeesha

    fohdeesha Active Member

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    CX4 electrically is 4x serial lanes of 2.5gbps each, and SFP+ is electrically 1 serial lane @ 10gbps. They would need some type of SERDES chip in there I would imagine to serialize and de-serialize the 1 giant lane from the SFP+ connection into 4x separate serial streams

    but who knows I've been wrong before
     
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  8. AveryFreeman

    AveryFreeman ESXi + ( BSD / ZFS ) = HAPPY

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    That's very interesting, I had no idea. I've never worked with any 10GbE equipment before. Do you think going from 10GBase-T to CX-4 would be cheaper/easier?
     
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