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While looking for a 16- or 24-port gigabit ethernet switch with at least 6 VLANs and port mirroring (packet duplication to a monitoring port), I came up with three candidates (there are more): Cisco SRW2024, Netgear GS724T and HP ProCurve 1810G

I need any VLAN to be capable of at least one full GigE-communication between two ports that is not disturbed by any other traffic.

What I can't figure out is: Are these switches capable of switching multiple full-load GigE-links that sum up to 6xGigE? In the past this was known as the backplane capacity (especially when stacking multiple switches to form a giant broadcast domain) but now some don't give any information (HP in the case of the J9450A) and the others state "Nonblocking, store-and-forward switching mechanism" or even "Bandwidth: 48 Gbps".

Is it common knowledge that GigE switches handle anything you send to them as long as no single-link capacity is overloaded?

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From my past experience, avoid Netgear. –  ITGuy24 Oct 28 '09 at 13:46
    
Agreed, avoid Netgear. Also avoid the Cisco/Linksys Express series. Get a real cisco switch, proper Catalyst series, 2960 series or so. –  Tom O'Connor Jan 6 '10 at 22:55
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All three of the links you provided specify 48Gbps of throughput/bandwidth/switching-capacity if you read their specs. So yes, you'll be fine for full 1/2Gbps-to-1/2Gbps port-to-port linking with any of them.

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The english HP specs actually state 48Gps. Astonished and happy. –  Paul Oct 28 '09 at 13:37
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All of that is typically marketing BS where they take the speed each port can do and double it because it can go full duplex. Having them say they can do 48Gbps doesn't mean they'll handle a loaded backplane –  sparks Oct 28 '09 at 19:16
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Many manufacturers claim 48Gbps capacity for such switches, but there may still be significant differences in performance. You also need to compare packets/sec capacity and switching latency (if you can even find those specs in product literature).

For example, recently I replaced a Netgear JGS524 (24-port gig unmanaged) with a Cisco 2960G-24 in an iSCSI network; and the before-and-after benchmarks (bonnie++ on an iSCSI filesystem) showed 30-40% improvements in throughput and 10-20% improvements in latency.

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To make it short an simple:

  1. Netgear - I had diverse trouble with those, avoid them

  2. Cisco - great gear no question, but higher pricetag

  3. HP - my recommendation, good performance and easy to configure

Best regards...

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I went with the HP switch and it works flawlessly. No fan I could hear, meaningful LEDs, plenty of VLANs. But does it switch 48 GiBit/s? Well I don't know. That is because I had to learn that even the "server style" Intel dual-port GigE-cards seem to allow 1 GiBit/s through any of their ports at any given time - both directions combined! Full duplex sending and receiving with 1 GiBit/s each is not possible.

Since only one cable runs from each PC to the switch and my test had 6 PCs, the best I could see was 3 GiBit/s total through the switch. In fact, I did see 3 GiBit/s so it seems at least the bandwidth is realistic.

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That's weird, I know that all of the servers we buy can flood a 1Gbps NIC from ram-disk to ram-disk quite easily, sounds odd. –  Chopper3 Jan 6 '10 at 22:01
    
Well if that is locally, no NIC will be involved. If it is server to server or even NIC port to (another) NIC port on the same server, it would be compatible with my observation. What I did: Server A sends to server B and B sends to A. Both connected with one port to the switch each. Both try to max out their connection/direction (TCP with sufficiently increased window size). The sum of the transfers was never >1GiBit/s. Do you achieve more in this situation? –  Paul Jan 6 '10 at 22:14
    
Sorry, I meant via GigE from two different servers but using data on ram drives to ensure there's no disk jitter slowing down the NIC testing, sorry I wasn't clear. Oh and we've only ever tried it 'one-way', i.e. not duplex but do get a full 1Gb - might try to test it duplex now actually :) –  Chopper3 Jan 6 '10 at 22:36
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