On Wed, Mar 05, 2003 at 01:34:20PM -0500, Alan Altmark wrote:
> On Wednesday, 03/05/2003 at 07:54 ZE2, Sergey Korzhevsky
> <[EMAIL PROTECTED]> wrote:
> > What is the difference between this commands?
> >
> > My linux has OSA (eth) and hsi interfaces. And OSA isn't primary router.
> > So, what should i do, to connect Hipersocket's network with outside LAN
> > through my Linux eth interface?
>
> 3 possibilities:
> - Make your OSA connection the primary router.  (That is what primary
> router is designed for.  Why do people resist this?)

I have a little rant about this.  I'll postpone that until the end of
the message, because I'm going to say it with *feeling*, and I'd prefer
that people read my other points before deleting the message in disgust.

People resist this because, at this stage in the game, your mainframe
is, very probably, mostly used for z/OS.  Linux is a pilot project, with
a minimal budget if you're lucky.  The z/OS guys are at the top of
the food chain, and they got their LPAR to be the one with the PRIROUTER
OSA port.  Of course, primary_router is a dumb idea for any case except
that of "I have several z/OS LPARs, and I want one of them to do the
routing for everyone."  But I'll get to that rant, as promised, later.

It doesn't help that the z/OS guys are, more than likely, also all, "AND
THIS IP STUFF IS NEW AND WEIRD AND SCARY.  WHY, IT TOOK ME 8 YEARS TO
GET ANY CONNECTIVITY AT ALL RUNNING AND NO ONE, BUT NO ONE, IS GOING TO
TOUCH IT NOW THAT I FINALLY HAVE PACKETS FLOWING.  BACK OFF, I SAY!
BACK OFF!"

> - Change your OSA to OSE (LCS) and use OSA/SF to add all of your
> HiperSocket IP addresses to the OAT

Wait, wait, wait.  Is this the same Alan Altmark who just a few days ago
was saying that Proxy ARP was a bad workaround that would at best just
delay your pain?  Because this solution is basically Proxy ARP, just
done at the IP rather than the MAC layer.  Not to mention, of course,
that you probably bought your OSA because it was fast, which LCS,
whatever its virtues, generally isn't.

> - Don't create the dummy device when using add_vipa4.  If you create the
> dummy device, Linux thinks the packet is local and won't route it.  But
> don't try to use OSPF or RIP because it won't see the interface.

And, of course, if you *don't* use a routing protocol, then you have the
problem of "how do I advertise my virtual address"?  And then you're
back to some hastily glued-together solution that involves a bunch of
tossing gratuitous ARPs around, and a whole sackful of similar ick.
This, when, clearly the *easy* way to do it (albeit more
resource-intensive) is to define a VIPA address, bound to dummy0, and
advertise it as a host route via OSPF.  This doesn't solve your "Can't
route through the OSA unless it's PRIROUTER" problem though.

So, here's the rant.

WHY, oh WHY can we not have something that's a *DUMB* OSA?  I don't
*want* a card that refuses packets that aren't for itself, that tries to
figure out if anyone else has the same IP address set, that tries to be
cleverer than I am and consistently fails.  I want a network device,
into which I can plug a piece of fiber (yes, I want this at GbE speed)
that behaves LIKE EVERY OTHER PIECE OF ETHERNET KIT ON THE PLANET.  I
want it to do broadcast, deliver packets, and GET OUT OF MY WAY.  I
don't want to have to fight with portnames and primary_router settings.
All I want--and I don't see what would make it hard--is a network device
that plugged into the QDIO infrastructure and let me put packets on, and
take packets off, the wire (or more likely, glass).  Let *ME* worry
about whether someone else already has my IP address, and don't try to
be clever about "Hey, not my packet--I'm GOING TO THROW IT AWAY!  Sure,
it could be for someone behind me, but, you know what, I'm NOT PRIROUTER
SO IT'S NOT MY JOB!  HA HA HA!  PACKET, MEET FLOOR!  FLOOR, PACKET!"[*]
If I'd wanted an OSA card in the Teamsters' Union I'd have specified
one.  All I ask for is a device, that, when I tell Linux it's eth0,
requires neither more nor less attention than, oh, the $8 RTL8139 in
this box I'm typing this from here.  From the Linux perspective, it
would look just like a HiperSockets interface, except that it could
attach to a real network (if it were a real device) and it *was able to
do broadcast*.

Yes, I'm sure that the OSA, as designed, works really really well for
shops sharing a single OSA across six MVS, er, OS/390, er z/OS LPARs.
But since it's also the preferred solution for getting traffic into a
penguin farm, could we have something a bit more suited to that task?
Please?

Adam

[*] Related to this:
"Hey, look, a DEVICE DRIVER!  Hey, buddy, what do you THINK my PORTNAME
is?  Hunh?  WRONG!  HAW!  I AIN'T GONNA TALK TO YOU NO MORE!  GUESS
AGAIN!  HAW!  HAW!"

I admit that my anthropomorphization of the OSA is, perhaps, just a wee
bit unfair.

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