Subject: Mbone Apps on Pentiums running Solaris ?

From: [email-masked] (Koodli Rajeev NRC/Boston)
Date: Thu, 30 Oct 1997 17:03:00 -0500

Hi,

I am trying to figure out what's the best choice for running mbone applications from among the following.

1. Solaris 2.6 on a Pentium 266. Pardon me, is there a Solaris 2.6 for PCs ?

2. Linux on a similar Pentium

3. Windows95/NT on a Pentium.

I don't like the 3rd option considering how scarce it is to find well tested mbone applications for the windows95/nt platforms.

Thanks much.

 -Rajeev

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From: "Forrest W. Christian" <[email-masked]>
Date: Thu, 30 Oct 1997 20:34:18 -0700 (MST)

> 1. Solaris 2.6 on a Pentium 266. Pardon me, is there a Solaris 2.6 for PCs ?

No experience.  However, I do know that I tried to get the multicast tools
running on a sparc running 2.5.1 or 2.6 (not sure which one) and ran into
some problems.  Can't remember what they were though...

> 2. Linux on a similar Pentium

Not recommended.  I spent much time with mrouted.  Couldn't get it to
prune.  I also am aware that mrouted and apps cannot work on the same
linux box.  Possibly ok for just running the apps, though if you don't
need mrouted.

> I don't like the 3rd option considering how scarce it is to find well
> tested mbone applications for the windows95/nt platforms.

Agreed.  The main problem I've ran into is the lack of apps that work
well.  Trying to get an audio tool to run on my windows 95 box was real
fun, even though it still doesn't work right.

How about option 4:

4.  FreeBSD on similar box.

This is what I'm using.  Works great, although I have a flaky sound card
which I need to replace.   Recommend a PAS 16 or GUS MAX/ New GUS PnP
pro? for audio.  I've been running vic and wb on it along with mrouted
without a hitch.  I also have vat/rat running on an Win 95 box attached to
it's ethernet port.  The mrouting works well, Win95 doesn't.

The only problems I'm having is due to the sound card I have in the
machine.  It's an old SB 16 value card and this card and FreeBSD doesn't
get along very well.  I fully expect the problem to go away as soon as I
can find a suitable replacement.

Freebsd can be installed over the net from http://www.freebsd.org  (I
highly recommend the net installation, especially if you have sufficient
bandwidth for an MBONE feed.)  Basically you create a boot disk, boot it
with it and answer a few questions and walk away for an hour and come back
and your done.

IT even installs most of the mbone apps by default with certain packages.

If you need more info, just drop me a note.

[email-masked]

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From: "Heiko W. Rupp" <[email-masked]>
Date: Fri, 31 Oct 1997 09:30:14 +0100

> linux box.  Possibly ok for just running the apps, though if you don't

I am no Linux fan at all, but this is not entirely true. I ran apps
(mcntp) on linux with and without mrouted. Both without problems.

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From: Carsten Bormann <[email-masked]>
Date: Fri, 31 Oct 1997 10:17:10 +0100 (MET)

> (mcntp) on linux with and without mrouted. Both without problems.

Sure, *you* won't have problems with a badly pruning Linux mrouted,
just the rest of the world around you will.

Gruesse, Carsten

(PS.: It strangely occurs to me this statement would apply to mcntp
itself, too...)

---

From: Malcolm Beattie <[email-masked]>
Date: Fri, 31 Oct 1997 10:16:53 +0000 (GMT)

> just the rest of the world around you will.

The original message which suggested that Linux wasn't suitable
(from [email-masked]) brought up two claims to justify that
conclusion:
  (1) Linux is less secure than FreeBSD.
        That's wrong. Look at CERT announcements and postings to the
        bugtraq mailing list, comp.security newsgroups and similar
        places. Leaving aside the security holes in userland
        applications which apply to FreeBSD, Linux and usually many
        other O/Ses (and don't affect the relative security between
        FreeBSD and Linux), that leaves kernel security holes and
        systems-level security holes (e.g. daemons, suid utilities
        and such like). There have been roughly the same number of
        security holes for daemons reported against both Linux and
        FreeBSD. On the kernel side, FreeBSD is losing: the two most
        recent kernel security holes both affect BSDs (FreeBSD, in
        particular, for this discussion) but not Linux. Those are the
        open() bug (which lets anyone open raw device files) and the
        rfork() bug (letting people manipulate file descriptors of
        suid executables to gain access to protected files).
  (2) you can find MBone apps already compiled.

[email-masked] said:
> Compiling the popular MBone apps is a bitch (get the source code, find
> the matching and right combination of tcl/tk, compile tcl, compile tk,
> compile the MBone app, etc...) and you want to avoid it.

     If you do have to compile anything yourself, the RPM package
     system used by the RedHat Linux distribution (or the dpkg system
     used by Debian) both let you install/de-install installations of
     version of packages like Tcl and Tk very easily.

Another message, from "Forrest W. Christian" <[email-masked]>,

> linux box.  Possibly ok for just running the apps, though if you don't

That's also wrong. I've been running mrouted and multi-cast applications
(e.g. from nv, sd, vat, wb to vic, sdr) on and off on the same Linux box
for well over a year. There have been kernel bugs fixed in the multicast
routing in that time but "cannot work" is absolutely wrong.

Finally, as to Linux mrouted not pruning properly, I suspect that that
was one of the kernel bugs now fixed. I've tried both mrouted 3.81 and
mrouted 3.9beta2 (I'm currrently using the latter) with Linux 2.0.31 and
it appears to be working fine. I've noticed before on this mailing list
some odd dubious claims about Linux problems with multicasting. Some
document true bugs which are tracked down and fixed. Some, however, seem
to be third-hand rumours which the senders never bother to check.

I'd therefore like to ask those on the list with first-hand experience
of mrouted and kernel multicast routing the two questions about
Linux/multicast which I haven't found good answers to yet:

(1) Is the claim about pruning made above true for current kernels
(2.0.31) or was it a bug which (if it existed) has now been fixed?

(2) Another rumour on this list is that mrouted under Linux has
problems tunnelling out to other hosts. Is that true? I currently have
Linux mrouted running as a leaf node but I'll be setting up tunnels to
others soon. As far as I'm aware, no outstanding Linux kernel multicast
bugs have shown up in the developers mailing list for a long time.
Possibly that's because there really aren't any, because the main
developers haven't mentioned them to the list or because nobody has
given any bug reports. If it's either of the latter two cases, I'd like
to see detailed bug reports here and I'll either forward them to the
relevant lists/people and/or try to fix them myself.

--Malcolm

-- 
Malcolm Beattie <[email-masked]>
Unix Systems Programmer
Oxford University Computing Services

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From: "Forrest W. Christian" <[email-masked]>
Date: Fri, 31 Oct 1997 13:26:36 -0700 (MST)

Ok, I'd like to clarify a couple of things I said:

1) (paraphrasing): Couldn't get linux to prune.

This was under 2.0.29 and 2.0.30, which were the latest kernels available.
2.0.29 was on my machine.  I upgraded to 2.0.30 to try to fix the problem.
Also tried to recompile mrouted 3.8 or whatever the latest was.  I just
couldn't get it to prune.   As far as if it is fixed in 2.0.31, I'm not
sure and I haven't had time to get 2.0.31 on there.

2.  Linux apps/mrouted on the same box

I haven't had any personal experience with this actually.  What I do know
is the following:

    1.   mrouted with a tunnel to a cisco router and "forwarding"
         the multicast packets to an attached ethernet on linux
         works fairly well, except with a non-pruned feed (see-above)
         this had some quality problems.  I was using the apps on a
         computer on the ethernet and they seemed to work, although
         I was mostly trying to get pruning to work at the time.

    2.   There were some discussions here and other places (from the 
         archives) that if you were tunneling to an linux
         box AND running apps on that same linux box that the multicast
         packets wouldn't make it to the apps.  I have no way to verify
         this as I'm not running X on the linux box, so I'm not sure
         how true this is.

[email-masked]

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From: Brad Parker <[email-masked]>
Date: Fri, 31 Oct 1997 21:53:55 -0500

I've had to much candy corn, but here goes:

>sure and I haven't had time to get 2.0.31 on there.

There were linux kernel bugs in pre 2.0.32 which would cause

1) cache misses to be lost (if the socket queue overflowed)
2) outbound tunnels to send packets into space

I think that inbound tunnels worked ok but (1) above could cause
some prunes to not be sent.  Much worse (IMHO) was the poor pre-3.9
mrouted behavior regarding prunes.  On lossy networks, when the upstream
router was loosing 20-50% of the traffic, the prunes would be sent
but then dropped.  Not resending them aggressively would caused my poor
little T1 to get swamped.  Sending them very aggressively fixed the
problem in a hacked 3.8.  Looks like 3.9 fixes this correctly (thanks Bill!)

also the out of the box mrouted 3.8 would not work on linux because
not all linux sockets allow ip ioctl's (don't blame me).  this is
also fixed in mrouted 3.9 (again - thanks to Bill for adding the fixes)

so, mrouted 3.9 might be the best cure for pre 2.0.32 linux kernels...

>         this as I'm not running X on the linux box, so I'm not sure

I have not seen this.  I have heard that apps running on the router
can't source multicast traffic.  I've been meaning to track this down
but have not...  Certainly inbound traffic works fine and gets routed
correctly.  I've watched a lot of video and heard a lot of audio using
linux to a sound blaster - it's not fancy but it does allow me to
stay home.

-brad