| RE: Note 778.0 "Ethernet AM multiple addresses"
> Is there any way to get the Ethernet AM to use two addresses when it
> attempts to communicate with a station? ...
The whole purpose of providing the ALTERNATE ADDRESS was to allow
for support of DECnet Phase IV stations (which is basically what
you're asking for).
Can I assume that you have Registered the Station as:
REGISTER STATION name ADDRESS hdwe-address,
ALTERNATE ADDRESS decnet-physical-address,
FUNCTIONS SUPPORTED DEC_ENETV2
> I tried using the Alternate Address but the AM only uses this new
> address, not the physical address.
If you specify the Station's NAME in a request, the Ethernet AM will
first try using ALTERNATE ADDRESS (if there is one), then try using
ADDRESS (it's actually a little more complicated than that given retries
and multiple ethernet ports...).
If you specify ALTERNATE ADDRESS in a request, that's all that the
Ethernet AM attempts to use. The reason for this: ALTERNATE ADDRESS is
not a key into the namespace (it isn't necessarily unique, and thus is
not an "IDENTIFIER" in the EMA sense), so the AM can't get the other
address (it can't get the NAME either). If you're interested (few
people are :-), I can give you the details on WHY this is the case.
I'm not sure what happens when ADDRESS is specified as the instance
in a request (I don't have the docs handy), but suspect that we will
acquire the NAME/ALTERNATE ADDRESS and try both addresses on a SHOW
(but only the specified address on a TEST...).
Hope this answers your question...
Chris Brienen
|
| I tried a few more experiments and it all depends on the Functions
Supported.
If it is DEC_ENETV2 or DEC_IEEE802, it uses both addresses but if it
id ENETV2_Only or IEEE802_Only it only uses one and never does any
retries.
I'll use the DEC_* ones instead, they give me more information anyway.
Alistair Roxburgh
|