topic Re: --REGARDING NCL--- in Operating System - OpenVMS

--REGARDING NCL---

Mrityunjoy Kundu — Wed, 28 Feb 2007 00:26:19 GMT

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.

Re: --REGARDING NCL---

Steven Schweda — Wed, 28 Feb 2007 00:43:37 GMT

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

Re: --REGARDING NCL---

Colin Butcher — Thu, 01 Mar 2007 06:58:07 GMT

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).

Re: --REGARDING NCL---

atul sardana — Thu, 01 Mar 2007 16:48:21 GMT

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.

Re: --REGARDING NCL---

Hoff — Thu, 01 Mar 2007 17:27:47 GMT

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.

Re: --REGARDING NCL---

Steven Schweda — Thu, 01 Mar 2007 17:38:58 GMT

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.

Re: --REGARDING NCL---

Wim Van den Wyngaert — Fri, 02 Mar 2007 08:14:15 GMT

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

Re: --REGARDING NCL---

Mrityunjoy Kundu — Mon, 05 Mar 2007 04:43:54 GMT

Thanks...for help me...