DECSERVERS visible in LATCP

[David B Sneddon · Accepted solution]

Wim,

Although the DECservers are configured to announce
services, if none are configured you won't see them.
$ MCR LATCP SHOW NODE *
will only show nodes that are actually offering
a LAT service. If you are only seeing 2 of your
10 servers, then only those 2 are likely offering
some service.
If the DECservers are used for terminal access to
a VAX or Alpha then they will not have any
services to announce so you won't see them.
$ MCR LATCP SHOW SERVICE
should show what they are offering.

Regards
Dave

[Wim Van den Wyngaert]

David,

You hit the nail on his head.

Antonio was hot too.

show service local showed no service on the ones NOT present in the latcp show node. On the ones that were present, some stupid unused service was present.

Thanks to all.

1 question left. How is a node getting the mac address of a decserver if this decserver is not broadcasting it ?

[David B Sneddon]

Wim,

Since you are using TSM when you see the MAC
address (it's a long time since I used TSM) I
seem to recall that TSM has a database, or uses
the existing one. You are doing

$ TSM SHOW SERVER CTS*

which implies that TSM knows about servers
called CTS* -- in a database somewhere.

Regards
Dave

[Wim Van den Wyngaert]

David,

Indeed TSM has a database. But TSM is only present on some nodes, not all nodes.
How do the ones without TSM get the mac address ?

Wim

[Wim Van den Wyngaert]

To put my problem in other words :

We certainly have decservers that are not in the TSM database. How can I find them without scanning the 2 towers we are in.

E.g. I found an unlabeled one but the mac address is on the back and I can not unplug it from the hub900.

[Anton van Ruitenbeek]

Wim,

The easy way to get the info of a terminalserver is to go with a terminal/notebook to the server, plug a serial connection and do a show server. If not (because all of them are REMOTE) a brute way is to connect in port 1, reboot.
If you have managed servers, you can ask for the mac-addressen on console of these.
(08-00-2B) are also DEC.

If $ SET HOST/LAT doesn't work, try:
$ SET HOST/MOP/CIRCUIT=/ADDRESS=
or
$ MC LANCP CONNECT NODE /device=

eq: CSMACD-1
eq: EID0

AvR

[Wim Van den Wyngaert]

Anton,

Unfortunately a portable (or a vt) is not available. It is easier to get a GS160 than a portable over here.

And I only know 1 location of where to find an unknown one. I need the others too.

Wim

[David B Sneddon]

Wim,

How many nodes (Alphas) are there? Are they
clustered?
I don't quite understand the problem about the
nodes WITHOUT TSM knowing the mac address.
LAT builds an internal database based on what
it sees.

To see LAT traffic you could use a thing called
DBS-LATWATCH available from
www.users.bigpond.com/dbsneddon/software.htm
(shameless plug :-)
You can choose to select different message types
e.g. service anouncements. If you put the mac
addresses of the decservers you do know about
into the NODELIST.DAT file used by LATWATCH then
you can do something like
$ LATWATCH/FROM=UNKNOWN
to get the mac addresses of the others.

Regards
Dave

[Terry Yeomans]

Wim,
you may find Decserver's set up in the following file:
SYS$SYSROOT:[SYSMGR]NET$MOP_CIRCUIT_STARTUP.NCL;
This is where we used to set up the mac addresses for DecServer's in the old days.
The best option for connecting to them via mop is:
SET HOST /MOP /DISCON=D /CIRCUIT=circuit
/ADDRESS=mac_address
Hope this helps.
Terry.

[Wim Van den Wyngaert]

David

About 140 Alphas, of which about 80 stations.

TSM is used to manage the decservers. It is not used by LAT.

So, how does a node translates a name to an address if there are no broadcasts ?

Terry,

What you defined is only used by MOP when it is part of decnet. The alternative is MOP via LANCP setup. But this is not used by LAT for obtaining the address (MOP can be set up on another node than the node using the decserver).

Wim

[David B Sneddon]

Wim,

Can you show me an example of what you mean by
the following, on a node _not_ running TSM?

> So, how does a node translates a name to an
> address if there are no broadcasts ?

When a terminal on a DECserver initiates a connection
to a host, part of the initial communication
involves the DECserver sending its name to the
host. So once a DECserver has connected to a
host, that host stores the information in an
internal database that LAT maintains.
Since the packet also includes tha MAC address
of the DECserver, LAT then has a table of
nodename / MAC address pairs.
I don't have my LAT protocol spec handy, I
observed this using LATWATCH.

Regards
Dave

[Wim Van den Wyngaert]

David,

To avoid confusion, ignore TSM. Consider the question as in a TSM less environment.

Is there any way to probe that LAT cache that contains the address translation ? I thought that "latcp show node" contained that info.

Wim

[Anton van Ruitenbeek]

Wim,

Buy a GS1280, connect the serial port OPA0 or TTAx to the DECserver and do SET HOST/DTE OPA0 or TTAx .
But anyway, if you have an Alpha nearby you can do it with the ports of the Alpha. This was exactly what I did with a costumer. At the computerroom there were no VT's and I didnt had my notebook with me. So I did it with OPA0.

AvR

[David B Sneddon]

Wim,

$ MCR LATCP SHOW NODE */FULL

will show you all that LAT knows about.

Dave

[Wim Van den Wyngaert]

David,

No it doesn't !!!

mc latcp sho conn

ID Type Remote Node (Address) Sessions/Limit
---- -------- ------------------------------------- --------------
0168 Incoming CTS12G (00-00-F8-52-6D-EB) 8/128
02F0 Incoming CTS12I (00-00-F8-52-6D-50) 6/128
032C Incoming CTS12H (00-00-F8-52-6D-EC) 8/128
04BC Incoming WOPER3 (AA-00-04-00-67-28) 3/ 16
059C Incoming WAPP01 (AA-00-04-00-E7-80) 1/ 16

mc latcp show node cts12g
%LAT-W-CMDERROR, error reported by command executor
-LAT-W-NODECNTRSONLY, only counter information is available for this node

[David B Sneddon]

Wim,

Did you want to know where the names came from
in the following?

0168 Incoming CTS12G (00-00-F8-52-6D-EB) 8/128
02F0 Incoming CTS12I (00-00-F8-52-6D-50) 6/128

The association with names and mac addresses is
determined when the connection is established
as I explained before.

Dave

[Terry Yeomans]

Wim,
for more info type
MC LATCP
SHOW CONN
SHOW CONN /FULL connect_id
(ie the first column id number) Does this help ?
Yours Terry.

[Wim Van den Wyngaert]

So the address is show with show conn/fu. Fine. But why isn't it shown when I do show node ? Only the counters are available (what is not true because the address is known too).

Wim

[Antoniov.]

Wim,
you you are very able to write a little DCL script to catch output of command MC LATCP SH CONN and store all MAC address of your Terminal server in a little database.
After this it's very simple connect a console to terminal server, for example using decnet IV:
$ MC NCP VIA PHYSICAL ADDR
or using other commands in previous post.

Antonio Vigliotti

[David B Sneddon]

Wim,

I just set up a DECserver here at home.
It is not advertising any services.
I connect from the DECserver to my Alpha.
LATCP SHOW CONN shows the active connection.
LATCP SHOW NODE name/FULL shows all info.
I logout and disconnect the session.
LATCP SHOW CONN shows no connections.
LATCP SHOW NODE name/FULL still shows all
the info on the DECserver.

Dave

[David B Sneddon]

Wim,

Just did some more testing...
With VMS 7.3-2 I get the results as in my last
response.
On a VMS 7.1 system I get the "only counter
info" message.
On a VMS 7.2-2 system it works as per 7.3-2.
What version of VMS are you using?

Dave

[Wim Van den Wyngaert]

David,

6.2 7.2 : counter msg

I checked on all 100+ systems and all see the same 2 servers (also the 7.3 machines that don't have a connection).

Antonio

I am looking for all servers, not only those with connections.
Btw : I will give you points because I gave to little when you were hot)

Wim

[David B Sneddon]

Wim,

I think I have the answer...
From the point of view of LAT, a "node" is an
entity that offers a service. In this case, LAT
gathers information about the "node". So any
"node" that has at any time offered a service
is kept in the internal database -- even after
it no longer offers any services. This is what
I was seeing last night.
I did some more checking today at work and am
seeing the same thing you are.

Dave

[Wim Van den Wyngaert]

Thus there are 3 things :
. offered services (show servi)
. nodes offering services (show node)
. nodes not offering services (missing show)

So 1 command is missing because LAT received broadcast and has the addresses.

So, there is no way to find all decservers except when using a sniffer.

Case closed. Thanks for your help David.

[Ian Miller.]

and if you want to know more about the LAT protocol then read Davids excellent LATWATCH program (previously mentioned). The LAT protcol is not publicly documented but much can be learned from LATWATCH.