We had a problem with a Dell server with on-board 10GbE SFP+ did not want to negotiate properly with a HP switch over a HP DAC cable. Convincing HP that it wasn't a server-side problem, and Dell that it wasn't a switch/cable problem, was so much work that we just gave up on DAC and switched to fiber or 10GBASE-T.
Skylar On Tue, Dec 8, 2015 at 5:47 AM, Edmund White <[email protected]> wrote: > With SFP+ DAC, you only really need to so with the switch in terms of > compatibility. E.g. Use HP-coded transceivers. > > -- > Edmund White > [email protected] > 847-530-1605 > > From: <[email protected]> on behalf of Skylar Thompson < > [email protected]> > Reply-To: "[email protected]" <[email protected]> > Date: Tuesday, December 8, 2015 at 3:44 AM > To: Doug Hughes <[email protected]> > Cc: Lopsa Discussion <[email protected]> > Subject: Re: [lopsa-discuss] Question on 10GB cabling in a server room > > We've tried using SFP+ DAC cabling, but found managing compatibility to be > pretty challenging. Unlike fiber, you are locked into having the same > transceiver brand at both ends. We have HP switches at the core but mostly > Dell servers, which proved to be problematic. > > Skylar > > On Mon, Dec 7, 2015 at 8:45 PM, Doug Hughes <[email protected]> wrote: > >> We mostly stick with SFP+ based switches and use SFP+ DAC, Active >> Optical, or fiber, depending upon distance. The switches are a bit cheaper, >> use less power, and have more connectivity options. But, if you need to >> leverage your existing copper infrastructure for some reason, then the RJ45 >> connections are probably your best bet. If you are talking about server >> room, I'd stick with SFP+. $.02, YMMV >> >> >> On Tue, Dec 8, 2015 at 1:08 AM, Skylar Thompson < >> [email protected]> wrote: >> >>> The two drawbacks I'm aware of with Cat6a are that it's much heavier >>> than Cat6, and much less flexible. Using twisted-pair has the advantage >>> over fiber of being a bit cheaper (no separate transceivers needed) and a >>> little denser (at least for our switch modules). >>> >>> Skylar >>> >>> On Mon, Dec 7, 2015 at 10:59 AM, John Stoffel <[email protected]> wrote: >>> >>>> >>>>> "Ski" == Ski Kacoroski <[email protected]> writes: >>>> >>>> Ski> We are rewiring our server room to support 10GB. The folks we >>>> Ski> talked to initially said that for the relatively short distances >>>> Ski> in the server room (less that 100ft) we can get by with cat 6 >>>> Ski> cabling for the patch cables from device to patch panel and >>>> Ski> probably even between patch panels because the distance is so >>>> Ski> short. The installer is saying that he will not certify that we >>>> Ski> will get 10GB unless we use cat 6A every where because of its >>>> Ski> shielding that stops alien crosstalk. >>>> >>>> I guess I wonder what the cost difference is between Cat6 and Cat6a >>>> is, and why you're not going with the better cable, just to make sure >>>> you don't have wonky problems down the line? >>>> >>>> I must admit that we've mostly just run fibre for 10g connections. >>>> >>>> John >>>> _______________________________________________ >>>> Discuss mailing list >>>> [email protected] >>>> https://lists.lopsa.org/cgi-bin/mailman/listinfo/discuss >>>> This list provided by the League of Professional System Administrators >>>> http://lopsa.org/ >>>> >>> >>> >>> _______________________________________________ >>> Discuss mailing list >>> [email protected] >>> https://lists.lopsa.org/cgi-bin/mailman/listinfo/discuss >>> This list provided by the League of Professional System Administrators >>> http://lopsa.org/ >>> >>> >> >> _______________________________________________ >> Discuss mailing list >> [email protected] >> https://lists.lopsa.org/cgi-bin/mailman/listinfo/discuss >> This list provided by the League of Professional System Administrators >> http://lopsa.org/ >> >> >
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