Slow network with F13 [SOLVED]

Bill Davidsen davidsen at
Sat Aug 28 21:10:49 UTC 2010

Roberto Ragusa wrote:
> Bill Davidsen wrote:
>> Roberto Ragusa wrote:
>>> john wendel wrote:
>>>> Looks like I'll spend a little time poking at F13 scp and see if I can 
>>>> improve the transfer speed.
>>> Maybe you are using compression? Compression is a disadvantage when
>>> the network is fast (gigabit); you just spend CPU time.
>>> Then there is encryption. That can't be turned off. I would love
>>> an option --no-crypto for scp or rsync+ssh on local networks, but
>>> there is none: you are forced to turn to rcp or rsh or nc tricks.
>> There actually is a patch to provide encryption "none" to improve speed and 
>> reduce CPU for trusted connections.
>> HINT: sure would be a nice addition to Fedora FC14!!
>> It's really desirable for doing scp or ssh to/from a VM from the host. Why spend 
>> CPU encrypting a connection which is as trusted as possible? Note that for just 
>> file transfer netcat can be useful if you have the firewall set to allow it.
> I didn't know about this patch. There is also a bug on Ubuntu (54180), but it
> looks like nothing has moved.
> So let's hope we will have it someday.
> BTW, about compression, we just have gzip. Where is LZMA? It would be useful
> on slow links (e.g., all ADSL uplinks) :-)
> Maybe extra ciphers and compressions could be handled as plugins.
Well good idea, but the patch I mentioned is out for inclusion now, and so 
represents a minimal effort. I agree that plug-ins would be nice, but they must 
not replace existing code or compression, for security reasons. If a plugin 
could be compromised... better to compile stuff in, what's there is adequate, 
the "none" crypto is a special case.

Bill Davidsen <davidsen at>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot

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