mtu

mtu

[Igor Gueths]

Hi. Has anyone successfully changed their mtu value on their network interface? I am unable to do this via /etc/network/interfaces. I put mtu 1000 after the line where it says iface eth0 inet dhcp. I restarted inetd and init, and the value hasn't changed. Does anyone know how to go about doing this? Thanks! 


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Re: mtu

[Johan Bergström]

On Mon, 25 Mar 2002, Igor Gueths wrote:

> Hi. Has anyone successfully changed their mtu value on their network
>interface? I am unable to do this via /etc/network/interfaces. I put mtu
>1000 after the line where it says iface eth0 inet dhcp. I restarted inetd
>and init, and the value hasn't changed. Does anyone know how to go about
>doing this? Thanks!
>

Why would you want to change your mtu? The standards say mtu 1500 for
ethernet. Anyway, I did do some tests a couple of years ago, and changing
mtu values on a network card almost never give better results than the
standard ones. It might happen in extreme cases but not one that I found
out about.

Johbe

--
  "I'm gonna go build my own theme park... with blackjack and hookers! In
fact, forget the park!" -Bender

Re: mtu

[Kerry Hoath]

I can't see why you'd want to do this on an ethernet
interface anyway since ethernet is tuned to handle mtu of 1500 and reducing it
is just going to increase wire overhead and do nothing more.
MTU discovery means that if something else has a lower mtu this will be communicated back
to the kernel and th e networking stack will take care of it.
Well just because I don't know why you want to do this doesn't mean it can't be done.
Once the route to the interface is in place you need to del the route and re-add it
with the mtu value so for example:
route del 192.168.1.0
route add -net 192.168.1.0 dev eth0 mtu 768
and I think the ip tools can do this too
try ip route help 
and
ip nei help

Regards, Kerry.
On Mon, Mar 25, 2002 at 08:19:13PM -0500, Igor Gueths wrote:
> Hi. Has anyone successfully changed their mtu value on their network interface? I am unable to do this via /etc/network/interfaces. I put mtu 1000 after the line where it says iface eth0 inet dhcp. I restarted inetd and init, and the value hasn't changed. Does anyone know how to go about doing this? Thanks! 
> 
> 
> _________________________________________________________
> Do You Yahoo!?
> Get your free @yahoo.com address at http://mail.yahoo.com
> 
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
> 
> 

-- 
Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au

Re: mtu

[Igor Gueths]

Hi Johan. Did you raise the mtu? Because this is what I'm trying to do to try and improve transfer rates. The mtu used to increase the performance of my card when I used to use winblows. I already notice a speed difference under Linux, I just want to try and max it out that's all. 
----- Original Message ----- 
From: Johan Bergström <johbe@linux.se>
To: <speakup@braille.uwo.ca>
Sent: Tuesday, March 26, 2002 2:34 AM
Subject: Re: mtu


> On Mon, 25 Mar 2002, Igor Gueths wrote:
> 
> > Hi. Has anyone successfully changed their mtu value on their network
> >interface? I am unable to do this via /etc/network/interfaces. I put mtu
> >1000 after the line where it says iface eth0 inet dhcp. I restarted inetd
> >and init, and the value hasn't changed. Does anyone know how to go about
> >doing this? Thanks!
> >
> 
> Why would you want to change your mtu? The standards say mtu 1500 for
> ethernet. Anyway, I did do some tests a couple of years ago, and changing
> mtu values on a network card almost never give better results than the
> standard ones. It might happen in extreme cases but not one that I found
> out about.
> 
> Johbe
> 
> --
>   "I'm gonna go build my own theme park... with blackjack and hookers! In
> fact, forget the park!" -Bender
> 
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup


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Re: mtu

[Igor Gueths]

Hi Kerry. Wouldn't increasing the mtu value decrease over head? Because I am trying to raise the value to 10000 or something, not lower it. 
----- Original Message ----- 
From: Kerry Hoath <kerry@gotss.net>
To: <speakup@braille.uwo.ca>
Sent: Tuesday, March 26, 2002 6:46 AM
Subject: Re: mtu


> I can't see why you'd want to do this on an ethernet
> interface anyway since ethernet is tuned to handle mtu of 1500 and reducing it
> is just going to increase wire overhead and do nothing more.
> MTU discovery means that if something else has a lower mtu this will be communicated back
> to the kernel and th e networking stack will take care of it.
> Well just because I don't know why you want to do this doesn't mean it can't be done.
> Once the route to the interface is in place you need to del the route and re-add it
> with the mtu value so for example:
> route del 192.168.1.0
> route add -net 192.168.1.0 dev eth0 mtu 768
> and I think the ip tools can do this too
> try ip route help 
> and
> ip nei help
> 
> Regards, Kerry.
> On Mon, Mar 25, 2002 at 08:19:13PM -0500, Igor Gueths wrote:
> > Hi. Has anyone successfully changed their mtu value on their network interface? I am unable to do this via /etc/network/interfaces. I put mtu 1000 after the line where it says iface eth0 inet dhcp. I restarted inetd and init, and the value hasn't changed. Does anyone know how to go about doing this? Thanks! 
> > 
> > 
> > _________________________________________________________
> > Do You Yahoo!?
> > Get your free @yahoo.com address at http://mail.yahoo.com
> > 
> > 
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > 
> > 
> 
> -- 
> Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup


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Re: mtu

[Igor Gueths]

What I was trying to do was use ifconfig to change the mtu to 10000.
----- Original Message ----- 
From: Kerry Hoath <kerry@gotss.net>
To: <speakup@braille.uwo.ca>
Sent: Tuesday, March 26, 2002 6:46 AM
Subject: Re: mtu


> I can't see why you'd want to do this on an ethernet
> interface anyway since ethernet is tuned to handle mtu of 1500 and reducing it
> is just going to increase wire overhead and do nothing more.
> MTU discovery means that if something else has a lower mtu this will be communicated back
> to the kernel and th e networking stack will take care of it.
> Well just because I don't know why you want to do this doesn't mean it can't be done.
> Once the route to the interface is in place you need to del the route and re-add it
> with the mtu value so for example:
> route del 192.168.1.0
> route add -net 192.168.1.0 dev eth0 mtu 768
> and I think the ip tools can do this too
> try ip route help 
> and
> ip nei help
> 
> Regards, Kerry.
> On Mon, Mar 25, 2002 at 08:19:13PM -0500, Igor Gueths wrote:
> > Hi. Has anyone successfully changed their mtu value on their network interface? I am unable to do this via /etc/network/interfaces. I put mtu 1000 after the line where it says iface eth0 inet dhcp. I restarted inetd and init, and the value hasn't changed. Does anyone know how to go about doing this? Thanks! 
> > 
> > 
> > _________________________________________________________
> > Do You Yahoo!?
> > Get your free @yahoo.com address at http://mail.yahoo.com
> > 
> > 
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > 
> > 
> 
> -- 
> Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup


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Re: mtu

[Kerry Hoath]

What sort of card is it and what sort of transferrs
are you trying to increase t he speed of?
Remember ssh requires cpu for encryptian and
samba has other options you set to increase speed.

Regards, Kerry.
On Tue, Mar 26, 2002 at 02:26:25PM -0500, Igor Gueths wrote:
> Hi Johan. Did you raise the mtu? Because this is what I'm trying to do to try and improve transfer rates. The mtu used to increase the performance of my card when I used to use winblows. I already notice a speed difference under Linux, I just want to try and max it out that's all. 
> ----- Original Message ----- 
> From: Johan Bergström <johbe@linux.se>
> To: <speakup@braille.uwo.ca>
> Sent: Tuesday, March 26, 2002 2:34 AM
> Subject: Re: mtu
> 
> 
> > On Mon, 25 Mar 2002, Igor Gueths wrote:
> > 
> > > Hi. Has anyone successfully changed their mtu value on their network
> > >interface? I am unable to do this via /etc/network/interfaces. I put mtu
> > >1000 after the line where it says iface eth0 inet dhcp. I restarted inetd
> > >and init, and the value hasn't changed. Does anyone know how to go about
> > >doing this? Thanks!
> > >
> > 
> > Why would you want to change your mtu? The standards say mtu 1500 for
> > ethernet. Anyway, I did do some tests a couple of years ago, and changing
> > mtu values on a network card almost never give better results than the
> > standard ones. It might happen in extreme cases but not one that I found
> > out about.
> > 
> > Johbe
> > 
> > --
> >   "I'm gonna go build my own theme park... with blackjack and hookers! In
> > fact, forget the park!" -Bender
> > 
> > 
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> 
> 
> _________________________________________________________
> Do You Yahoo!?
> Get your free @yahoo.com address at http://mail.yahoo.com
> 
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
> 

-- 
Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au

Re: mtu

[Kerry Hoath]

The ethernet frame size is 1524 bytes. You can't
raise the mtu higher than that you just end up with a pile of back to back
full-sized ethernet frames and loose performance due to the
fragmentation.
What transferrs are you trying to speed up and what sort of card is this? There may
be other options you can tweak that don't involve fooling with the 
framesize on ethernet.
Increasing mtu can also cause problems with cards that are not capable of
receiving giant frames. You're also violating
the ethernet standards if you exceed the maximum framesize.
I doubt you will gain any performance by reducing wire overhead, your
need for speed can be solved in other ways. How fast is this machine and is the
card isa/pci?
If it isn't a pci busmaster and is an rtl8029, it's a cheap
card and is a connectivity solution. Snap it in half and go buy a real card
if speed and system performance is important to you or tolerate
the slower speeds to save money.
3com 905 cards cost a lot of money for a good reason, they are fast
efficient and easy on cpu.
The rtl8029 and rtl8139 are mass market pci ethernet chips that aren't known
for speed. Linux usually drives them as best it can but
there are all sorts of hardware limitations to work around and
bugs that bite.

Regards, Kerry.
On Tue, Mar 26, 2002 at 02:28:26PM -0500, Igor Gueths wrote:
> Hi Kerry. Wouldn't increasing the mtu value decrease over head? Because I am trying to raise the value to 10000 or something, not lower it. 
> ----- Original Message ----- 
> From: Kerry Hoath <kerry@gotss.net>
> To: <speakup@braille.uwo.ca>
> Sent: Tuesday, March 26, 2002 6:46 AM
> Subject: Re: mtu
> 
> 
> > I can't see why you'd want to do this on an ethernet
> > interface anyway since ethernet is tuned to handle mtu of 1500 and reducing it
> > is just going to increase wire overhead and do nothing more.
> > MTU discovery means that if something else has a lower mtu this will be communicated back
> > to the kernel and th e networking stack will take care of it.
> > Well just because I don't know why you want to do this doesn't mean it can't be done.
> > Once the route to the interface is in place you need to del the route and re-add it
> > with the mtu value so for example:
> > route del 192.168.1.0
> > route add -net 192.168.1.0 dev eth0 mtu 768
> > and I think the ip tools can do this too
> > try ip route help 
> > and
> > ip nei help
> > 
> > Regards, Kerry.
> > On Mon, Mar 25, 2002 at 08:19:13PM -0500, Igor Gueths wrote:
> > > Hi. Has anyone successfully changed their mtu value on their network interface? I am unable to do this via /etc/network/interfaces. I put mtu 1000 after the line where it says iface eth0 inet dhcp. I restarted inetd and init, and the value hasn't changed. Does anyone know how to go about doing this? Thanks! 
> > > 
> > > 
> > > _________________________________________________________
> > > Do You Yahoo!?
> > > Get your free @yahoo.com address at http://mail.yahoo.com
> > > 
> > > 
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > 
> > > 
> > 
> > -- 
> > Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> > ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> > 
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> 
> 
> _________________________________________________________
> Do You Yahoo!?
> Get your free @yahoo.com address at http://mail.yahoo.com
> 
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
> 

-- 
Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au

Re: mtu

[Igor Gueths]

Actually, now that I think about it, ifconfig doesn't mention receive mtu. Up to now, I have been talking about receive mtu. 
----- Original Message ----- 
From: Kerry Hoath <kerry@gotss.net>
To: <speakup@braille.uwo.ca>
Sent: Tuesday, March 26, 2002 3:16 PM
Subject: Re: mtu


> What sort of card is it and what sort of transferrs
> are you trying to increase t he speed of?
> Remember ssh requires cpu for encryptian and
> samba has other options you set to increase speed.
> 
> Regards, Kerry.
> On Tue, Mar 26, 2002 at 02:26:25PM -0500, Igor Gueths wrote:
> > Hi Johan. Did you raise the mtu? Because this is what I'm trying to do to try and improve transfer rates. The mtu used to increase the performance of my card when I used to use winblows. I already notice a speed difference under Linux, I just want to try and max it out that's all. 
> > ----- Original Message ----- 
> > From: Johan Bergström <johbe@linux.se>
> > To: <speakup@braille.uwo.ca>
> > Sent: Tuesday, March 26, 2002 2:34 AM
> > Subject: Re: mtu
> > 
> > 
> > > On Mon, 25 Mar 2002, Igor Gueths wrote:
> > > 
> > > > Hi. Has anyone successfully changed their mtu value on their network
> > > >interface? I am unable to do this via /etc/network/interfaces. I put mtu
> > > >1000 after the line where it says iface eth0 inet dhcp. I restarted inetd
> > > >and init, and the value hasn't changed. Does anyone know how to go about
> > > >doing this? Thanks!
> > > >
> > > 
> > > Why would you want to change your mtu? The standards say mtu 1500 for
> > > ethernet. Anyway, I did do some tests a couple of years ago, and changing
> > > mtu values on a network card almost never give better results than the
> > > standard ones. It might happen in extreme cases but not one that I found
> > > out about.
> > > 
> > > Johbe
> > > 
> > > --
> > >   "I'm gonna go build my own theme park... with blackjack and hookers! In
> > > fact, forget the park!" -Bender
> > > 
> > > 
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > 
> > 
> > _________________________________________________________
> > Do You Yahoo!?
> > Get your free @yahoo.com address at http://mail.yahoo.com
> > 
> > 
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > 
> 
> -- 
> Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup


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Re: mtu

[Igor Gueths]

Hi Kerry. I actually have an lne100TX, and I think it does pretty good for speed. What other options could I tweak for speed improvements could I manipulate? 
----- Original Message ----- 
From: Kerry Hoath <kerry@gotss.net>
To: <speakup@braille.uwo.ca>
Sent: Tuesday, March 26, 2002 3:23 PM
Subject: Re: mtu


> The ethernet frame size is 1524 bytes. You can't
> raise the mtu higher than that you just end up with a pile of back to back
> full-sized ethernet frames and loose performance due to the
> fragmentation.
> What transferrs are you trying to speed up and what sort of card is this? There may
> be other options you can tweak that don't involve fooling with the 
> framesize on ethernet.
> Increasing mtu can also cause problems with cards that are not capable of
> receiving giant frames. You're also violating
> the ethernet standards if you exceed the maximum framesize.
> I doubt you will gain any performance by reducing wire overhead, your
> need for speed can be solved in other ways. How fast is this machine and is the
> card isa/pci?
> If it isn't a pci busmaster and is an rtl8029, it's a cheap
> card and is a connectivity solution. Snap it in half and go buy a real card
> if speed and system performance is important to you or tolerate
> the slower speeds to save money.
> 3com 905 cards cost a lot of money for a good reason, they are fast
> efficient and easy on cpu.
> The rtl8029 and rtl8139 are mass market pci ethernet chips that aren't known
> for speed. Linux usually drives them as best it can but
> there are all sorts of hardware limitations to work around and
> bugs that bite.
> 
> Regards, Kerry.
> On Tue, Mar 26, 2002 at 02:28:26PM -0500, Igor Gueths wrote:
> > Hi Kerry. Wouldn't increasing the mtu value decrease over head? Because I am trying to raise the value to 10000 or something, not lower it. 
> > ----- Original Message ----- 
> > From: Kerry Hoath <kerry@gotss.net>
> > To: <speakup@braille.uwo.ca>
> > Sent: Tuesday, March 26, 2002 6:46 AM
> > Subject: Re: mtu
> > 
> > 
> > > I can't see why you'd want to do this on an ethernet
> > > interface anyway since ethernet is tuned to handle mtu of 1500 and reducing it
> > > is just going to increase wire overhead and do nothing more.
> > > MTU discovery means that if something else has a lower mtu this will be communicated back
> > > to the kernel and th e networking stack will take care of it.
> > > Well just because I don't know why you want to do this doesn't mean it can't be done.
> > > Once the route to the interface is in place you need to del the route and re-add it
> > > with the mtu value so for example:
> > > route del 192.168.1.0
> > > route add -net 192.168.1.0 dev eth0 mtu 768
> > > and I think the ip tools can do this too
> > > try ip route help 
> > > and
> > > ip nei help
> > > 
> > > Regards, Kerry.
> > > On Mon, Mar 25, 2002 at 08:19:13PM -0500, Igor Gueths wrote:
> > > > Hi. Has anyone successfully changed their mtu value on their network interface? I am unable to do this via /etc/network/interfaces. I put mtu 1000 after the line where it says iface eth0 inet dhcp. I restarted inetd and init, and the value hasn't changed. Does anyone know how to go about doing this? Thanks! 
> > > > 
> > > > 
> > > > _________________________________________________________
> > > > Do You Yahoo!?
> > > > Get your free @yahoo.com address at http://mail.yahoo.com
> > > > 
> > > > 
> > > > _______________________________________________
> > > > Speakup mailing list
> > > > Speakup@braille.uwo.ca
> > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > > 
> > > > 
> > > 
> > > -- 
> > > Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> > > ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> > > 
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > 
> > 
> > _________________________________________________________
> > Do You Yahoo!?
> > Get your free @yahoo.com address at http://mail.yahoo.com
> > 
> > 
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > 
> 
> -- 
> Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup


_________________________________________________________
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Getting Ready to Take the Plunge

[Liz Hare]

Hi,

I'm finally getting to take the plunge and install Redhat.  (I've chosen 
Redhat because it apparently works well with some of the applications that 
woule be useful in my research.)

My problem is that I only have a modem, and apparently the download will 
take *days*.  My ISP cuts me off too frequently .  Is there any other way 
to get the Speakup-Redhat install CD's?

Thanks,


Liz Hare, Ph.D.
Research Associate
Animal Breeding and Genetics Group
B47 Morrison Hall
Cornell University
Ithaca, NY 14853
(607) 255 2380
eh51@cornell.edu

Re: mtu

[Brian Borowski]

You should not increase the MTU above 1500, you are just causing other
devices further upstream to have to segment your packets, to say nothing of
the fact, that you can't send out a packet with more than 1500 bytes inside
an ethernet frame; 1500 is the maximum you can put into an ethernet packet;
though, as Kerry said 1524 is the ethernet frame size, and it can hole 1500
bytes of whatever you put into it.  If you increase the MTU you will
actually slow things down.  If you want to play with other parameters that
could effect transfer efficiency depending upon the speed of your link,
propagation-delay ETC, then fiddle with things like TCP winow-size, MSS,
(though, I don't know why you'd want to play with that either), and other
things like that.

You'd only ever want to change MTU if you're on a link using PPPOE (which I
use), and then the MTU is 1456 bytes or something like that; that's a bit
more overhead per packet, but that's the price you pay.  If you're on a
slow modem link, MTU might be set lower, to speed up response when you're
doing other things on the link, but those are some of the reasons you'd
want to adjust MTU.

Brian Borowski


On Wed, 27 Mar 2002, Kerry Hoath wrote:

> The ethernet frame size is 1524 bytes. You can't
> raise the mtu higher than that you just end up with a pile of back to back
> full-sized ethernet frames and loose performance due to the
> fragmentation.
> What transferrs are you trying to speed up and what sort of card is this? There may
> be other options you can tweak that don't involve fooling with the
> framesize on ethernet.
> Increasing mtu can also cause problems with cards that are not capable of
> receiving giant frames. You're also violating
> the ethernet standards if you exceed the maximum framesize.
> I doubt you will gain any performance by reducing wire overhead, your
> need for speed can be solved in other ways. How fast is this machine and is the
> card isa/pci?
> If it isn't a pci busmaster and is an rtl8029, it's a cheap
> card and is a connectivity solution. Snap it in half and go buy a real card
> if speed and system performance is important to you or tolerate
> the slower speeds to save money.
> 3com 905 cards cost a lot of money for a good reason, they are fast
> efficient and easy on cpu.
> The rtl8029 and rtl8139 are mass market pci ethernet chips that aren't known
> for speed. Linux usually drives them as best it can but
> there are all sorts of hardware limitations to work around and
> bugs that bite.
>
> Regards, Kerry.
> On Tue, Mar 26, 2002 at 02:28:26PM -0500, Igor Gueths wrote:
> > Hi Kerry. Wouldn't increasing the mtu value decrease over head? Because I am trying to raise the value to 10000 or something, not lower it.
> > ----- Original Message -----
> > From: Kerry Hoath <kerry@gotss.net>
> > To: <speakup@braille.uwo.ca>
> > Sent: Tuesday, March 26, 2002 6:46 AM
> > Subject: Re: mtu
> >
> >
> > > I can't see why you'd want to do this on an ethernet
> > > interface anyway since ethernet is tuned to handle mtu of 1500 and reducing it
> > > is just going to increase wire overhead and do nothing more.
> > > MTU discovery means that if something else has a lower mtu this will be communicated back
> > > to the kernel and th e networking stack will take care of it.
> > > Well just because I don't know why you want to do this doesn't mean it can't be done.
> > > Once the route to the interface is in place you need to del the route and re-add it
> > > with the mtu value so for example:
> > > route del 192.168.1.0
> > > route add -net 192.168.1.0 dev eth0 mtu 768
> > > and I think the ip tools can do this too
> > > try ip route help
> > > and
> > > ip nei help
> > >
> > > Regards, Kerry.
> > > On Mon, Mar 25, 2002 at 08:19:13PM -0500, Igor Gueths wrote:
> > > > Hi. Has anyone successfully changed their mtu value on their network interface? I am unable to do this via /etc/network/interfaces. I put mtu 1000 after the line where it says iface eth0 inet dhcp. I restarted inetd and init, and the value hasn't changed. Does anyone know how to go about doing this? Thanks!
> > > >
> > > >
> > > > _________________________________________________________
> > > > Do You Yahoo!?
> > > > Get your free @yahoo.com address at http://mail.yahoo.com
> > > >
> > > >
> > > > _______________________________________________
> > > > Speakup mailing list
> > > > Speakup@braille.uwo.ca
> > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > >
> > > >
> > >
> > > --
> > > Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> > > ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> > >
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> >
> >
> > _________________________________________________________
> > Do You Yahoo!?
> > Get your free @yahoo.com address at http://mail.yahoo.com
> >
> >
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> >
>
> --
> Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
>
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
>
>

Re: mtu

[Kerry Hoath]

What sort of network card are you talking about?
And mtu stands for Maximum transmition unit so it referrs to the bigest packet
the kernel will *send*.
mru is maximum receive u nit but that is a ppp parameter not an ethernet one.
On Tue, Mar 26, 2002 at 05:00:01PM -0500, Igor Gueths wrote:
> Actually, now that I think about it, ifconfig doesn't mention receive mtu. Up to now, I have been talking about receive mtu. 
> ----- Original Message ----- 
> From: Kerry Hoath <kerry@gotss.net>
> To: <speakup@braille.uwo.ca>
> Sent: Tuesday, March 26, 2002 3:16 PM
> Subject: Re: mtu
> 
> 
> > What sort of card is it and what sort of transferrs
> > are you trying to increase t he speed of?
> > Remember ssh requires cpu for encryptian and
> > samba has other options you set to increase speed.
> > 
> > Regards, Kerry.
> > On Tue, Mar 26, 2002 at 02:26:25PM -0500, Igor Gueths wrote:
> > > Hi Johan. Did you raise the mtu? Because this is what I'm trying to do to try and improve transfer rates. The mtu used to increase the performance of my card when I used to use winblows. I already notice a speed difference under Linux, I just want to try and max it out that's all. 
> > > ----- Original Message ----- 
> > > From: Johan Bergström <johbe@linux.se>
> > > To: <speakup@braille.uwo.ca>
> > > Sent: Tuesday, March 26, 2002 2:34 AM
> > > Subject: Re: mtu
> > > 
> > > 
> > > > On Mon, 25 Mar 2002, Igor Gueths wrote:
> > > > 
> > > > > Hi. Has anyone successfully changed their mtu value on their network
> > > > >interface? I am unable to do this via /etc/network/interfaces. I put mtu
> > > > >1000 after the line where it says iface eth0 inet dhcp. I restarted inetd
> > > > >and init, and the value hasn't changed. Does anyone know how to go about
> > > > >doing this? Thanks!
> > > > >
> > > > 
> > > > Why would you want to change your mtu? The standards say mtu 1500 for
> > > > ethernet. Anyway, I did do some tests a couple of years ago, and changing
> > > > mtu values on a network card almost never give better results than the
> > > > standard ones. It might happen in extreme cases but not one that I found
> > > > out about.
> > > > 
> > > > Johbe
> > > > 
> > > > --
> > > >   "I'm gonna go build my own theme park... with blackjack and hookers! In
> > > > fact, forget the park!" -Bender
> > > > 
> > > > 
> > > > _______________________________________________
> > > > Speakup mailing list
> > > > Speakup@braille.uwo.ca
> > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > 
> > > 
> > > _________________________________________________________
> > > Do You Yahoo!?
> > > Get your free @yahoo.com address at http://mail.yahoo.com
> > > 
> > > 
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > 
> > 
> > -- 
> > Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> > ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> > 
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> 
> 
> _________________________________________________________
> Do You Yahoo!?
> Get your free @yahoo.com address at http://mail.yahoo.com
> 
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
> 

-- 
Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au

Re: mtu

[Kerry Hoath]

lnp100tx, what driver do you load for this card?
I need to know so I know what sort of chip is on the card.
Is it the tulip driver?

Regards, Kerry.
On Tue, Mar 26, 2002 at 05:05:45PM -0500, Igor Gueths wrote:
> Hi Kerry. I actually have an lne100TX, and I think it does pretty good for speed. What other options could I tweak for speed improvements could I manipulate? 
> ----- Original Message ----- 
> From: Kerry Hoath <kerry@gotss.net>
> To: <speakup@braille.uwo.ca>
> Sent: Tuesday, March 26, 2002 3:23 PM
> Subject: Re: mtu
> 
> 
> > The ethernet frame size is 1524 bytes. You can't
> > raise the mtu higher than that you just end up with a pile of back to back
> > full-sized ethernet frames and loose performance due to the
> > fragmentation.
> > What transferrs are you trying to speed up and what sort of card is this? There may
> > be other options you can tweak that don't involve fooling with the 
> > framesize on ethernet.
> > Increasing mtu can also cause problems with cards that are not capable of
> > receiving giant frames. You're also violating
> > the ethernet standards if you exceed the maximum framesize.
> > I doubt you will gain any performance by reducing wire overhead, your
> > need for speed can be solved in other ways. How fast is this machine and is the
> > card isa/pci?
> > If it isn't a pci busmaster and is an rtl8029, it's a cheap
> > card and is a connectivity solution. Snap it in half and go buy a real card
> > if speed and system performance is important to you or tolerate
> > the slower speeds to save money.
> > 3com 905 cards cost a lot of money for a good reason, they are fast
> > efficient and easy on cpu.
> > The rtl8029 and rtl8139 are mass market pci ethernet chips that aren't known
> > for speed. Linux usually drives them as best it can but
> > there are all sorts of hardware limitations to work around and
> > bugs that bite.
> > 
> > Regards, Kerry.
> > On Tue, Mar 26, 2002 at 02:28:26PM -0500, Igor Gueths wrote:
> > > Hi Kerry. Wouldn't increasing the mtu value decrease over head? Because I am trying to raise the value to 10000 or something, not lower it. 
> > > ----- Original Message ----- 
> > > From: Kerry Hoath <kerry@gotss.net>
> > > To: <speakup@braille.uwo.ca>
> > > Sent: Tuesday, March 26, 2002 6:46 AM
> > > Subject: Re: mtu
> > > 
> > > 
> > > > I can't see why you'd want to do this on an ethernet
> > > > interface anyway since ethernet is tuned to handle mtu of 1500 and reducing it
> > > > is just going to increase wire overhead and do nothing more.
> > > > MTU discovery means that if something else has a lower mtu this will be communicated back
> > > > to the kernel and th e networking stack will take care of it.
> > > > Well just because I don't know why you want to do this doesn't mean it can't be done.
> > > > Once the route to the interface is in place you need to del the route and re-add it
> > > > with the mtu value so for example:
> > > > route del 192.168.1.0
> > > > route add -net 192.168.1.0 dev eth0 mtu 768
> > > > and I think the ip tools can do this too
> > > > try ip route help 
> > > > and
> > > > ip nei help
> > > > 
> > > > Regards, Kerry.
> > > > On Mon, Mar 25, 2002 at 08:19:13PM -0500, Igor Gueths wrote:
> > > > > Hi. Has anyone successfully changed their mtu value on their network interface? I am unable to do this via /etc/network/interfaces. I put mtu 1000 after the line where it says iface eth0 inet dhcp. I restarted inetd and init, and the value hasn't changed. Does anyone know how to go about doing this? Thanks! 
> > > > > 
> > > > > 
> > > > > _________________________________________________________
> > > > > Do You Yahoo!?
> > > > > Get your free @yahoo.com address at http://mail.yahoo.com
> > > > > 
> > > > > 
> > > > > _______________________________________________
> > > > > Speakup mailing list
> > > > > Speakup@braille.uwo.ca
> > > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > > > 
> > > > > 
> > > > 
> > > > -- 
> > > > Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> > > > ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> > > > 
> > > > _______________________________________________
> > > > Speakup mailing list
> > > > Speakup@braille.uwo.ca
> > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > 
> > > 
> > > _________________________________________________________
> > > Do You Yahoo!?
> > > Get your free @yahoo.com address at http://mail.yahoo.com
> > > 
> > > 
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > 
> > 
> > -- 
> > Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> > ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> > 
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> 
> 
> _________________________________________________________
> Do You Yahoo!?
> Get your free @yahoo.com address at http://mail.yahoo.com
> 
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
> 

-- 
Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au

Re: Getting Ready to Take the Plunge

[Kirk Reiser]

Hi Liz:  I suspect either Bill Acker or Janina would be willing to
send you some CD's.  Bill's address is wacker@octothorp.org and
Janina's escapes me currently.

  Kirk

-- 

Kirk Reiser				The Computer Braille Facility
e-mail: kirk@braille.uwo.ca		University of Western Ontario
phone: (519) 661-3061

Re: mtu

[Johan Bergström]

Yes I tried some diffrent values, but didnt notice anything but worse
performance. You can use ifconfig to set mtu on your network cards. Just
by typing ifconfig eth0 mtu 826 for example. You need to be root ofcourse.
Someone mentioned earlier about changing mtu on your routes aswell, this
might be necessary aswell. Take a look at the ip tool.

Johan


On Tue, 26 Mar 2002, Igor Gueths wrote:

> Hi Johan. Did you raise the mtu? Because this is what I'm trying to do
>to try and improve transfer rates. The mtu used to increase the
>performance of my card when I used to use winblows. I already notice a
>speed difference under Linux, I just want to try and max it out that's
>all.

--
 Fry: "They're great! They're like sex except I'm having them."

Re: mtu

[Igor Gueths]

Hi Kerry. My particular Linksys card uses the tulip driver. 
----- Original Message ----- 
From: Kerry Hoath <kerry@gotss.net>
To: <speakup@braille.uwo.ca>
Sent: Tuesday, March 26, 2002 8:51 PM
Subject: Re: mtu


> What sort of network card are you talking about?
> And mtu stands for Maximum transmition unit so it referrs to the bigest packet
> the kernel will *send*.
> mru is maximum receive u nit but that is a ppp parameter not an ethernet one.
> On Tue, Mar 26, 2002 at 05:00:01PM -0500, Igor Gueths wrote:
> > Actually, now that I think about it, ifconfig doesn't mention receive mtu. Up to now, I have been talking about receive mtu. 
> > ----- Original Message ----- 
> > From: Kerry Hoath <kerry@gotss.net>
> > To: <speakup@braille.uwo.ca>
> > Sent: Tuesday, March 26, 2002 3:16 PM
> > Subject: Re: mtu
> > 
> > 
> > > What sort of card is it and what sort of transferrs
> > > are you trying to increase t he speed of?
> > > Remember ssh requires cpu for encryptian and
> > > samba has other options you set to increase speed.
> > > 
> > > Regards, Kerry.
> > > On Tue, Mar 26, 2002 at 02:26:25PM -0500, Igor Gueths wrote:
> > > > Hi Johan. Did you raise the mtu? Because this is what I'm trying to do to try and improve transfer rates. The mtu used to increase the performance of my card when I used to use winblows. I already notice a speed difference under Linux, I just want to try and max it out that's all. 
> > > > ----- Original Message ----- 
> > > > From: Johan Bergström <johbe@linux.se>
> > > > To: <speakup@braille.uwo.ca>
> > > > Sent: Tuesday, March 26, 2002 2:34 AM
> > > > Subject: Re: mtu
> > > > 
> > > > 
> > > > > On Mon, 25 Mar 2002, Igor Gueths wrote:
> > > > > 
> > > > > > Hi. Has anyone successfully changed their mtu value on their network
> > > > > >interface? I am unable to do this via /etc/network/interfaces. I put mtu
> > > > > >1000 after the line where it says iface eth0 inet dhcp. I restarted inetd
> > > > > >and init, and the value hasn't changed. Does anyone know how to go about
> > > > > >doing this? Thanks!
> > > > > >
> > > > > 
> > > > > Why would you want to change your mtu? The standards say mtu 1500 for
> > > > > ethernet. Anyway, I did do some tests a couple of years ago, and changing
> > > > > mtu values on a network card almost never give better results than the
> > > > > standard ones. It might happen in extreme cases but not one that I found
> > > > > out about.
> > > > > 
> > > > > Johbe
> > > > > 
> > > > > --
> > > > >   "I'm gonna go build my own theme park... with blackjack and hookers! In
> > > > > fact, forget the park!" -Bender
> > > > > 
> > > > > 
> > > > > _______________________________________________
> > > > > Speakup mailing list
> > > > > Speakup@braille.uwo.ca
> > > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > > 
> > > > 
> > > > _________________________________________________________
> > > > Do You Yahoo!?
> > > > Get your free @yahoo.com address at http://mail.yahoo.com
> > > > 
> > > > 
> > > > _______________________________________________
> > > > Speakup mailing list
> > > > Speakup@braille.uwo.ca
> > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > > 
> > > 
> > > -- 
> > > Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> > > ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> > > 
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > 
> > 
> > _________________________________________________________
> > Do You Yahoo!?
> > Get your free @yahoo.com address at http://mail.yahoo.com
> > 
> > 
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > 
> 
> -- 
> Kerry Hoath:  kerry@gotss.net kerry@gotss.eu.org or  kerry@gotss.spice.net.au
> ICQ: 8226547 msn: kerry@gotss.net Yahoo: kerryhoath@yahoo.com.au
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup


_________________________________________________________
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