Re: network problem w/ ioc

["Dale L. Brewe" <brewe@pnc.aps.anl.gov>]

It seems the routing is in fact getting screwed up in some way. What seems 
to work is to add "routeAdd" lines to the ioc startup w/ the most necessary 
workstations. This has been working for an hour or so thus far. Thanks for 
everyone's help.
Dale
At 01:14 PM 8/25/99 , Maren Purves wrote:
> Dale,
>
> yes, the routers could act differently depending on how they are/were
> programmed. We don't use "routeAdd" as long as we stay on the same
> subnet. I just looked up an old startup file where the ioc (temporarily,
> we were still testing then) was on a different subnet than the devices
> it was connected to, and in that case we used a routeAdd that had the
> router's address and the subnet specified.
> My understanding is that a routeAdd "0" , "x.x.x.x" tells the router
> that all traffic is going "out" (and the programming of the router
> decides whether "out" really means "out" or not).
>
> Maren Purves
>
>
> Dale L. Brewe wrote:
> >
> > Chip
> > Well, something along these lines seems plausible, I guess, altho the
> > gateway has not changed, nor have the ioc parameters. However, these
> > problems surfaced a few days after a new main switch/router was installed.
> > Clearly the problem seems to be at a pretty basic level, as I have troubles
> > pinging the ioc with no CA clients running. I haven't found anything that
> > looks bad in either hardware or software. In the  ioc startup, I have
> > routeAdd "0", "x.x.x.x"  for our subnet gateway. Is this correct? It worked
> > before, but could the routers be acting differently for some reason?
> > Dale
> > At 08:08 AM 8/25/99 , Chip Watson wrote:
> > >Dale,
> > >
> > >Your problem is similar to one I tracked down at PSI. If you
> > >have a gateway (default routing node) improperly set in the
> > >boot parameters of the IOC, then the following scenario can
> > >happen:
> > >
> > >(1) the first client connects, but the ioc sends all traffic for
> > >that client through the gateway
> > >
> > >(2) the gateway eventually sends a message to the ioc telling it
> > >what the correct ethernet address for that host is (it doesn't want
> > >to carry traffic unnecessarily)
> > >
> > >(3) the ioc mistakenly updates the gateway address instead of
> > >installing an explicit host entry
> > >
> > >(4) the second client connects, and the ioc attempts to route
> > >all traffic through the gateway again, but now it uses the
> > >"updated" address for the gateway, which is client one
> > >
> > >(5) client one refuses to forward the packets (lazy, huh?), so
> > >the ioc appears to drop off the net for everyone except the
> > >first client to have connected
> > >
> > >Log into the ioc via the console if you can, and you can watch
> > >this scenario play out.  Then, check your boot parameters and
> > >either fix or remove the gateway entry.
> > >
> > >Chip

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Dale L. Brewe     PNC-CAT/U. of Washington
 ph: 630 252 0582         fax: 630 252 0580
 Mail:
 Argonne National Laboratory/APS
 Bldg 435E sector 20
 9700 S. Cass Ave.
 Argonne, IL 60439
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