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--REGARDING NCL---

 
Mrityunjoy Kundu
Frequent Advisor

--REGARDING NCL---

please help how can i detect remote decnet nodes are alive or not from my servers .Is there any ncl commands??
On our servers OpenVMS 7.3-2 is running and decnet phase V is installed.

7 REPLIES
Steven Schweda
Honored Contributor

Re: --REGARDING NCL---

The NCL help suggests something like this:

ALP $ mcr ncl loop loopback application name LOCAL:.alp2

Node 0 Loopback Application
at 2007-02-27-23:39:32.272-06:00I3.316


Start Time = 2007-02-27-23:39:32.247-06:00I3.316


But you'd better not be in a hurry if the
fellow at the other end is dead:

ALP $ pipe show time ; mcr ncl loop loopback application name LOCAL:.alpx ; show time
27-FEB-2007 23:39:56


Node 0 Loopback Application
at 2007-02-27-23:42:40.193-06:00I3.335

command failed due to:
process failure

The Connection to the remote mirror failed
Start Time = 2007-02-27-23:39:56.662-06:00I3.318
Reason = 32869556
27-FEB-2007 23:42:40
Colin Butcher
Esteemed Contributor

Re: --REGARDING NCL---

Hello,

DECnet will let you look at the adjacencies on the circuits. Do you have any DECnet routing nodes? If so then they will have a list of the adjacencies that they can see too.

Are you using "DECnet over IP" - if so then use TCPIP PING to probe the TCP/IP transpot layers.

Useful NCL commands are:

NCL> SHOW ROUTING CIRCUIT *

NCL> SHOW ROUTING CIRCUIT ADJACENCY * ALL

Also to do the same thing for a remote node (typically a router such as a DECnis) use the form:

NCL> SHOW NODE ROUTING CIRCUIT ADJACENY * ALL

Another easy way is to hook up a LAN analyser to the local ethernet network and capture packets for a while (longer than HELLO TIMER, which by default in Phase V is 5 minutes [I think] - I usually bring it down to say 30 seconds or less). Assuming that you're using Phase IV compatible addressing then you'll see packets with source addresses of the form AA-00-04-00-xx-yy where xx-yy will give you the DECnet Phase IV address (byte reverse, then convert to decimal, then modulo 1024 gives you the area and the remainder modulo 1024 gives you the number within the area). SCSNODE = * 1024 +

This might help with some of the background:
http://www.downloads.xdelta.co.uk/vmstjv5%20feb2005/decnet%20article%20vms%20tj%20v5%20feb2005.pdf

Cheers, Colin (www.xdelta.co.uk).
Entia non sunt multiplicanda praeter necessitatem (Occam's razor).
atul sardana
Frequent Advisor

Re: --REGARDING NCL---

Hi kundu,

you can check it very easily if you know decnet address of remote server and you can check decnet address of any system, give command in system prompt
$>>show net
Product: DECNET Node: horse Address(es): 12.23
Product: TCP/IP Node: horse Address(es): 10.192.0.23

As per your question now you can check it from another remote server by command
$>>set host 12.23
and remote node will connect definately if alive.

Atul Sardana.
I love VMS
Hoff
Honored Contributor

Re: --REGARDING NCL---

I understand the immediate question (and others have provided entirely valid suggestions), but I might ask your intended purpose here, and whether or not this is a cluster, and if it is feasible to hold open network connections to other nodes. With some added information around the problem, we might be able to provide a more targeted solution than simply polling a node for reachability. Polling certainly works, of course.
Steven Schweda
Honored Contributor

Re: --REGARDING NCL---

And with all questions like this, "alive"
can mean many things. Whether DECnet or IP,
being able to "ping" a node tells you that it
can do something, but that's not the same as
telling you that it can do what you want it
to do.

For example, if you need to know if the Web
server is operating properly, then try to
download a Web page. While some failures
can stop both from working, "ping" and an
HTTP download can generally succeed or fail
independently. On the DECnet side, SET HOST
tells you one thing, but not everything.
Wim Van den Wyngaert
Honored Contributor

Re: --REGARDING NCL---

You can check if the node is reachable by doing something like :
$ if f$sea("node::login.com") .nes. "" then ...

Of course your proxy must be well defined then.

Wim
Wim
Mrityunjoy Kundu
Frequent Advisor

Re: --REGARDING NCL---

Thanks...for help me...