Yeah, You are right. But I would like to use my nexus 5000 10GE/FCoE ports just for access servers, maximizing it's use... The uplinks from Nexus 2000 could easially go directly to my distribution/core. Unfortunally, nexus 2000 is just an fabric extender and can ONLY be attached to Nexus 5000... Maybe CISCO changes it's later...
Let's think: 10 nexus 2000 using all uplink ports = 40 ports. Yes, 40 ports that I must use at my nexus 5000. That's more than 1 entirelly switch (1RU) and almost 1 switch (2RU). I haven't figure out yet what's the advantage of having this design (nexus 2000 -> nexus 5000) other than the "old" one (catalyst 4948 -> nexus 7000/cisco 6500). That's what I'm talking about. The only REAL advantage so far is the vPC... 2010/2/2 Brad Hedlund <brhed...@cisco.com> > > True, the Nexus 2000 does not locally switch, but lets explore that for a > second... > > 1) a typical enterprise Data Center is running applications that are not > latency sensitive, where latencies in the 10s of microseconds are perfectly > OK and nobody is really counting anyway. Only in the small minority of Data > Centers running high frequency trading, grid computing, or some other ultra > low latency application, every *nanosecond* matters and local switching with > fewer hops is of paramount importance. Furthermore, these applications are > quickly migrating away from 1GE to 10GE attached servers for the obvious low > latency advantages. > > 2) the Nexus 2000 has 4x10GE uplink bandwidth versus the 2x10GE uplink for > 4948. This results in a possible 1:1.2 oversubscription ratio for Nexus > 2000 to handle the additional uplink load that may otherwise not be present > on a 4948. > > 3) The upstream Nexus 5000 implements cut-through switching, and the Nexus > 2000 itself also uses cut-through for frames entering on 1GE and egressing > on 10GE. The two combined often results in port-to-port latencies similar > to a Catalyst 6500, even without the "local switching". If you are > comfortable with your Catalyst 6500 local switching latencies, you can > expect similar performance from a Nexus 2000/5000 combination. > > > -- > Brad Hedlund, CCIE #5530 > Consulting Systems Engineer, Data Center > bhedl...@cisco.com > http://www.internetworkexpert.org > > > > On Jan 31, 2010, at 5:25 PM, David Hughes wrote: > > > > > On 29/01/2010, at 6:54 AM, Livio Zanol Puppim wrote: > > > >> Can anyone please tell me the advantages of using Nexus 2000 over > Catalyst > >> 4948 as access layers switches? > >> Using Nexus 2000, I have to use at least 2 ports at my Nexus 5000, that > >> could be used by servers with 10GbE/FCoE servers. > > > > The N2K does no local switching so if you have any east-west traffic > between ports on the same switch you'll be better served by a more > "traditional" access switch. Naturally the N2K offers centralised > management etc etc but that may or may not be of interest depending on the > size of your deployment. > > > > > > > > David > > ... > > _______________________________________________ > > cisco-nsp mailing list cisco-nsp@puck.nether.net > > https://puck.nether.net/mailman/listinfo/cisco-nsp > > archive at http://puck.nether.net/pipermail/cisco-nsp/ > > -- []'s LĂvio Zanol Puppim _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/