[YLUG] user mode linux and slirp

[Gaffer]

Hi Liam,

On Wednesday 24 January 2007 13:37, Liam Wilson inscribed thus:
> If only it were that simple! The version of slirp I
> have does not allow me to set the baudrate as it is
> supposed to run at the maximum possible rate.
>
> Could this be something to do with incorrect
> configuration of the network on the virtual machine?
> If run ifconfig I get:
> eth0      Link encap:Serial Line IP
>           inet addr:10.0.2.15  Mask:255.0.0.0
>           UP RUNNING NOARP  MTU:1500  Metric:1
>           RX packets:27 errors:0 dropped:0 overruns:0
> frame:0
>           TX packets:26 errors:0 dropped:0 overruns:0
> carrier:0
>           collisions:0 txqueuelen:256
>           RX bytes:3176 (3.1 Kb)  TX bytes:3601
> (3.5Kb)
>           Interrupt:5
>
> lo        Link encap:Local Loopback
>           inet addr:127.0.0.1  Mask:255.0.0.0
>           UP LOOPBACK RUNNING  MTU:16436  Metric:1
>           RX packets:4 errors:0 dropped:0 overruns:0
> frame:0
>           TX packets:4 errors:0 dropped:0 overruns:0
> carrier:0
>           collisions:0 txqueuelen:0
>           RX bytes:336 (336.0 b)  TX bytes:336 (336.0
> b)
> If that sheds any light?
>
> Liam
>
> --- Paul Gibbs <paul-listmonkey at pacem.plus.com> wrote:
> > I can tell you why it's slow (IIRC), but not how to
> > fix it...
> >
> > slirp recognises the importance of lo latency, it
> > also knows that many
> > serial interfaces have large buffers and so does its
> > own rate limiting.
> >
> > I'm surprised that you get 64KB/s I'd expect it to
> > limit by default to
> > 64Kb/s.
> >
> > Anyway you just need to find the correct
> > parameter....
> > ...and a quick Google says, (from
>
> http://www.cs.ualberta.ca/doc/Software_manuals/slirp.doc.txt)
>
> > to call
> > slirp with -b big-number-in-bits/s
> > Go to '8. Setting the "baudrate" Option' within that
> > document for more
> > details.
> >
> > Paul.<><
> >
> > Liam Wilson wrote:
> > > Hi
> > >
> > > I've just been playing around with user mode
> >
> > linux.
> >
> > > I've got myself a slackware 10.2 virtual machine
> >
> > which
> >
> > > I'm trying to use with slirp networking. I start
> >
> > the
> >
> > > machine with:
> > >
> > > vmlinux ubd0=root_fs eth0=slirp,,path/to/slirp
> > >
> > > One booted I bring up the network with:
> > >
> > > ifconfig eth0 10.0.2.15 up
> > > route add default dev eth0
> > >
> > > In my .slirprc file I have the line:
> > > redir tcp 5555 22 ie to allow me to ssh into the
> > > virtual machine.
> > > The problem is that data transfer from the machine
> >
> > is
> >
> > > very slow (about 64KB/s). I have the fullbolt
> >
> > version
> >
> > > of slirp from slirp_1.0.17-1_i386.deb which should
> > > work at full speed. This only affects data
> >
> > transfer
> >
> > > from the machine, when transfering data to the
> >
> > machine
> >
> > > I get about 2MB/s. Does anyone know a fix for
> >
> > this? I
> >
> > > was trying to run X applications on the machine so
> >
> > I
> >
> > > need as much bandwith as possible.
> > >
> > > Thanks
> > > Liam

Just guessing.  Anything to do with MTU ?  1460 maybe !

-- 
Best Regards:
             Derrick.