[Info-vax] tcpip gateway question

[Anton Shterenlikht]

On Tue, Sep 15, 2009 at 05:39:17AM -0700, jbriggs444 wrote:
> On Sep 15, 7:56?am, Anton Shterenlikht <me... at bristol.ac.uk> wrote:
> > On Tue, Sep 15, 2009 at 11:26:37AM +0000, Jan-Erik S?derholm wrote:
> > > > In addition to my previous MAC change observation, I discovered
> > > > that all nodes in the cluster have their current MAC addresses
> > > > for the first interface, either EWA0 (alpha) or EIA0 (i64) changed
> > > > to a range of incremental MAC numbers from AA-00-04-00-03-08 to
> > > > -06-08 (4 nodes). However, all MAC addresses for second interfaces,
> > > > EWB0 or EIB0 are left at default settings.
> >
> > > > I'm really puzzled by this. Is this an expected behaviour?
> > > > Is this something to do with VMS cluster or DECnet?
> > > > Can I insist that the current MAC address for a particular
> > > > interface is left as default setting?
> >
> > > DECnet when started change the MAC address. And it's built up
> > > based on the DECnet area.node address in som e way, if I'm not wrong.
> >
> > yes, it is in DECnet-Plus for OpenVMS Network Management, section 9.1,
> > table 9-1:
> >
> > ? ? ? ? "... in the format AA-00-04-00-xx-xx, where
> > ? ? ? ? xx-xx is calculated from Phase IV node address."
> >
> > I guess I have to reregister my ip address to this DECnet modified
> > MAC address. Or maybe better to assign the Uni ip address to the
> > second, unmodified interface, to make it independent of VMS cluster
> > configuration?
> 
> "reregister"?
> 
> In the typical environment there's no such concept.  The NIC is set to
> use the DECnet modified MAC address very early in the boot process.
> The network never sees any other MAC address.  As far as the network
> is concerned, the DECnet MAC address is the machine's true MAC
> address.
> 
> If your network runs on switch gear with port security (*) turned up
> and if you are required to register your MAC address with the network
> management people before connecting to the network then yes you need
> to either re-register the DECnet MAC address or turn off DECnet.

yes, that's exactly what I have - I'm required to register my MAC
to obtain the Uni ip address.

So before, when this box was running FreeBSD, it's default MAC
was registered to some ip address. Now, since DECnet is
installed on this box, I have to send the network people either

	a) the DECnet MAC address of this interface
or
	b) use the second interface, whose MAC is not
	modified by DECnet.

I think I got it now!

Many thanks to all who answered my questions.

anton

-- 
Anton Shterenlikht
Room 2.6, Queen's Building
Mech Eng Dept
Bristol University
University Walk, Bristol BS8 1TR, UK
Tel: +44 (0)117 331 5944
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