FTP problem
Archetti Luciano
If I make ftp from a PC the serveur UNIX I go to 1000 kb/s.
If I make ftp from PC serveur UNIX I go to 50 kb/s.
What could be?
Thanks Luciano
luc...@provincia.brescia.it
--
Luciano Archetti
Centro Elaborazione Dati
Provincia di Brescia
Via Milano 13 - 25126 BS
Phone: +39-030-3749-505
Fax: +39-030-3749-679
E-Mail: luc...@provincia.brescia.it
http://www.provincia.brescia.it
Bill Vermillion
Archetti Luciano <luc...@provincia.brescia.it> wrote:
>I have UNIX SCO 5,0,5.
>If I make ftp from a PC the serveur UNIX I go to 1000 kb/s.
>If I make ftp from PC serveur UNIX I go to 50 kb/s.
>What could be?
Anyone of a dozen or more things - which could vary from the brand
of NIC being used, settings on the NIC, wiring, hub/switch problem,
and so on.
If your card is set to automatically configure parameters based on
what is sees on the cable, then fix it to the known methods your
system can support. One major problem is the auto-negotiation
which sets the full/half duplex - and while you can get data
flowing between mixed duplex setups at time - it will be slow.
The other is the auto-sense, which tries to determine the speed
of the network whether you are running at 10Mbs or 100Mbs second.
Lock all settings to start with and go from there.
Some NIC cards are really flaky too. And you gave no indication of
what that might be.
For anyone who wants to more than they really need, you can see
that even the major vendors note that there are complex issues.
http://www.cisco.com/warp/public/473/46.html
It has to do with problems you may encounter with the Cicso
switches and has a lot of information.
Tony Lawrence
> In article <a0hc8o$7sd$1...@fe2.cs.interbusiness.it>,
> Archetti Luciano <luc...@provincia.brescia.it> wrote:
>
>>I have UNIX SCO 5,0,5.
>>If I make ftp from a PC the serveur UNIX I go to 1000 kb/s.
>>If I make ftp from PC serveur UNIX I go to 50 kb/s.
>>What could be?
>>
>
> Anyone of a dozen or more things - which could vary from the brand
> of NIC being used, settings on the NIC, wiring, hub/switch problem,
> and so on.
I'm wondering if there is more to this- I get this question a LOT, and I
give the same sort of answer you did, plus advising that any approprate
patches be installed, but maybe there is more .. ?
--
Tony Lawrence
SCO/Linux Support Tips, How-To's, Tests and more: http://pcunix.com
Matt Schalit
>I'm wondering if there is more to this- I get this question a LOT, and I
>give the same sort of answer you did, plus advising that any approprate
>patches be installed, but maybe there is more .. ?
Slow ftp in one direction was the first question
I ever asked here, at least five years ago.
It's not more complex than it has been since
that time.
We're still using the same 10/100 cards,
mixing ISA and pci, mixing duplex and speeds. Most
often it's auto-negotiation related, as we know.
Beware the reset button <-- That's my big discovery.
Power completely off and then on to be sure the
nics autonegotiate the way they were meant to.
Force all variables if necessary. Hubs are half
duplex only. Try matched nics. Use nic based sender-
responder tests. That sort of thing.
Matt
Bill Vermillion
>> In article <a0hc8o$7sd$1...@fe2.cs.interbusiness.it>,
>> Archetti Luciano <luc...@provincia.brescia.it> wrote:
>>>I have UNIX SCO 5,0,5.
>>>If I make ftp from a PC the serveur UNIX I go to 1000 kb/s.
>>>If I make ftp from PC serveur UNIX I go to 50 kb/s.
>>>What could be?
>> Anyone of a dozen or more things - which could vary from the brand
>> of NIC being used, settings on the NIC, wiring, hub/switch problem,
>> and so on.
>I'm wondering if there is more to this- I get this question a LOT,
>and I give the same sort of answer you did, plus advising that any
>approprate patches be installed, but maybe there is more .. ?
A great many times that I see this in another group it boils to one
common denominator - a RealTek NIC card. On an ISP mailing list it
has been noted that the NetGear switches seem to be some of the
best for getting things set properly. The URL I posted for Cicso
notes the problems that can occur and how to set things. You will
also seem some recommending that all network equipment come from
one manufacturer, and I don't recall if it was the Cicso list that
mentioned this or elsewhere, but where that comes into play is that
some manufacturers add extra features so these play together
nicely, but since they are not standard items they can confuse
other devices.
The problem is most often the auto-negotiation of duplex. The
auto-sense of speed seems to be reported to work most of the time
for most cards. I deduce this may be because that at 10Mbit you
have a carrier going on/off, so that you have periods with no
signal on the line, but the modulation scheme in 100Mbit is such
that a carrier is always present.
The 10Mbit is basically a data stream at that rate, while the
100Mbit uses encoding similar to the multi-bit per baud we first
saw in old analog modems. The 100Mbit carried freqency is about
33MHz and we get 3 bits on each change of state. So you can see
that in itself - a on/off carrier or constant carrier makes
auto-sensing easier. It's the auto negotiating that seems to be
the problem. The ISP group seems to fell the iNTEL cards are the
most reliable in virtually all instances.
Bill Vermillion
>
>> In article <a0hc8o$7sd$1...@fe2.cs.interbusiness.it>,
>> Archetti Luciano <luc...@provincia.brescia.it> wrote:
>>>I have UNIX SCO 5,0,5.
>>>If I make ftp from a PC the serveur UNIX I go to 1000 kb/s.
>>>If I make ftp from PC serveur UNIX I go to 50 kb/s.
>>>What could be?
>> Anyone of a dozen or more things - which could vary from the brand
>> of NIC being used, settings on the NIC, wiring, hub/switch problem,
>> and so on.
>I'm wondering if there is more to this- I get this question a LOT,
>and I give the same sort of answer you did, plus advising that any
>approprate patches be installed, but maybe there is more .. ?
I referenced the Cicso page in an earlier reply. I had time to
read through the printout today.
There are explicit references to small files transfering and large
files failing with specific references to NT. There are also
references to some 3C905 cards in specific configurations. Many of
the question here, particulary where I referenced the
auto-negotiation are shown in a chart table showing how different
settings on each piece give different defaults and why they may or
may not work. It's one of the better pieces I've seen on this
subject.