how can i use labview to monitor ethernet LAN devices

[48000]

hi all gurus

                     i am developing a LAN monitoring software . the network is ethernet and devices connected to it are SNMP compatible. i want to use labview to do this for me.  i want to know how cum this is possible . what support will labview give me in this context.  ur response will be highly appreciated

                                         thankyou

[altenbach]

SNMP queries involve simple UDP exchanges, you simply need to get the syntax right :o. rfc1157 could be used as a start.

Much easier would be the use of an SNMP toolkit such as http://sine.ni.com/nilex/DisplayLinkAction.do?id=2788EXT 🙂

[48000]

dear altenbach

                             is there some example already written in labview to monitor the health of LAN networks using ethernet.......or any other SNMP example available......because i havent work on SNMP before .....this looks like a monster to me........how ever i am very thankfull for ur cooperation

[Travis_M.]

Hello all,

It looks like its up to you to implement this protocol -- though it is possible with the TCP/IP VIs.  The only additonal resource I can add comes from this Knowledge Base entry: http://digital.ni.com/public.nsf/websearch/4CD3625A939A77DE852564050047D3BD?OpenDocument.

Hope it helps, and best of luck!

Message Edited by Travis M. on 01-30-2006 11:46 AM

[unclebump]

What specific info do you want to monitor on the LAN??

[Ben]

Last I heard, "ethereal" is the way to go. It is an open source version of "sniffer" (That Robert J. Schmalstieg of HP Support and I wrote back in 1988).

http://www.ethereal.com/download.html

Ben

[altenbach]

Well Ben, ethereal is quite a different kind of animal. It is a plain packet sniffer. It lets you monitor the raw packets as they arrive at your interface. While it is promiscuous (it sees packets with any destination ethernet address) it won't seem much more than broadcasts and multicasts in addition to it's own traffic in a typical switched network. Only on older networks that uses hubs instead of switches the traffic is not segmented and you see all packets on that particular network branch. This is rare today. (Of course there are ways around this, but it requires some work. Some high end managed switches allow monitoring on certain ports. Some cheap switches can be thrown into "hub mode" by flooding their ARP table with too many different (=thousands) entries ).

In contrast, a SNMP network monitor would (1) send queries at regular intervals to SNMP aware devices, parse the replies, and thus maintain a status of the network. For example, it could query adjacent routers for traffic statistics and graph them similar to MRTG . It could also (2) listen for SNMP traps. These are messages that SNMP devices send on their own if something important happens to them.

A full featured general SNMP monitor would require quite a bit of work. OTOH, implementing something simple like a MRTG clone in LabVIEW is probably not very hard. 🙂

[Ben]

Good points Christian!

It has been so many years since I worried about the low level stuff that I forgot that hubs have been replaced with switches.

So I guess we need to wait for an reply to Uncle's question "What specific info do you want to monitor on the LAN?? ".

Ben

I must be getting old! If the Open source version of code that replaced the code I wrote to run on an obsolete machine (VAX-11) is now obsolete... I guess that makes me obsolete ^2.

[altenbach]

Well, ethereal is by no means obsolete. 🙂

There are lots of interesting packets that are broad- or multicasts or directly targeted to your PC. Even more interesting are the packets that leave your PC. An analysis could be instrumental to discover a virus or trojan or identify the presence of spyware. 😉

[48000]

hay what i need exactly is.......

                                                i wana use SNMP.........2ndly i want to use labview interface for front end ..............i am using all this to just to monitor the health different nodes on LAN. like CPU load.....MEMORY status.....bandwidthUsage.........incoming outgoing trfic....nom of error messages. stuff like that...........also the functionality MRTG provides for network.......is this is possible.......if yes ......then any example of SNMP with labview is available........looking forward 🙂