On 26 May 2014 19:24, James Harper <james@ejbdigital.com.au> wrote:
On 26 May 2014 18:07, Russell Coker <russell@coker.com.au> wrote:
On Mon, 26 May 2014 17:47:06 Toby Corkindale wrote:
I don't understand why you're worried about enabling the jumbo frames though. It doesn't break backwards compatibility. Your 100baseT stuff will continue to function fine.
Except that a switch will drop a jumbo packet destined for a non-jumbo port. So you can have situations where things work at low speed but break as soon as you send lots of data and get a larger TCP segment size.
I've never seen that in practice, and I've been running gigabit networks for a while. Rather than totally dropping the packet if the destination port doesn't support it, the switch should alert the sender that they must fragment their packets. Path MTU discovery. Although actually I think some (most?) switches instead just do the fragmentation themselves.
This almost certainly isn't possible unless it's an L3 managed switch, and even then I've never heard of such a thing. IP is Layer 3 while Ethernet is Layer 2, which is all most switches do.
Ah OK. I stand corrected. There's definitely some mechanism that lets a jumbo-frame client talk to a non-jumbo-frame client via a switch though. I swear I do this and it Just Works(tm). Perhaps MSS at the IP layer then?
I'm confused. Russell asked about jumbo packets, but Toby's been talking about jumbo frames. https://en.wikipedia.org/wiki/Jumbo_frame "jumbo frames are Ethernet frames with more than 1500 bytes of payload." They're at L2 and routers have nothing to do with them. I've never heard of a "jumbo packet". The closest I can find is https://en.wikipedia.org/wiki/Jumbogram Which is it?
On 27/05/2014 5:19 AM, Jeremy Visser wrote:
On 27/05/14 11:54, Trent W. Buck wrote:
Russell asked about jumbo packets, but Toby's been talking about jumbo frames.
That's an unnecessary nitpick. You can assume they are the same thing for all intensive purposes.
Another unnecessary nitpick: *intensive* purposes?
On 27 May 2014 17:29, Anders Holmström <anders.sputnik@gmail.com> wrote:
That's an unnecessary nitpick. You can assume they are the same thing for all intensive purposes.
Another unnecessary nitpick: *intensive* purposes?
Another unnecessary nitpick: Are you sure that was a mistake? :-) -- Brian May <brian@microcomaustralia.com.au>
Way to go with worsening the signal to noise ratio, guys. By the way, out of everyone offering advice, I'm curious to know how many of you actually have relatively modern, non-esoteric, hardware that is a mixture of ethernet specifications and is using jumbo frames, and whether or not you've actually experienced any problems or not? I poll on the side of using jumbo frames at home, and it Just Working with my menagerie of hardware. I suspect almost all the traffic on my LAN is TCP though. On 28 May 2014 10:26, Brian May <brian@microcomaustralia.com.au> wrote:
On 27 May 2014 17:29, Anders Holmström <anders.sputnik@gmail.com> wrote:
That's an unnecessary nitpick. You can assume they are the same thing for all intensive purposes. Another unnecessary nitpick: *intensive* purposes? Another unnecessary nitpick: Are you sure that was a mistake?
On 28 May 2014, at 11:10 am, Toby Corkindale <toby@dryft.net> wrote:
I poll on the side of using jumbo frames at home, and it Just Working with my menagerie of hardware. I suspect almost all the traffic on my LAN is TCP though.
I have jumbo frames enabled on my QNAP NAS which uses a LACP/802.3ad bond to a managed NetGear switch. My wired main devices are my iMac desktop and various Linux-based servers. Some have jumbo frames enabled, some don’t. Also running dual-stack IPv4/v6 across most devices, with 100/40 FTTH routed via an Apple Airport Time Capsule. Everything Just Works(tm) and my read/write speed to the NFS mounts on the QNAP is ~110MB/s or so, with Internet speeds hitting the practical maximum of ~11MB/s. YMMV.
Toby Corkindale <toby@dryft.net> writes:
I'm curious to know how many of you actually have relatively modern, non-esoteric, hardware that is a mixture of ethernet specifications and is using jumbo frames, and whether or not you've actually experienced any problems or not?
I have one managed HP switch with six boards of about 24 ports each; all banks are gigE. I turned on jumbo frames once my main router[0] got gigE NICs. It hasn't caused problems, but I don't remember if I ever bothered to benchmark it afterward. By now the all the managed hosts are gigE, too, though there are certainly some 100mbps hosts around -- if only the TP-Link 1043ND's that provide wifi... no wait, those are gigE too. I didn't bother to mention it before because it is such a boring setup, not much *can* go wrong. [0] I have separate LANs for managed hosts, user BYOD, and the test lab.
participants (6)
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Anders Holmström -
Avi Miller -
Brian May -
Jeremy Visser -
Toby Corkindale -
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