Network utility for sending messages just to users on a switch

[mike13]

Hello,

Does anyone know of a network utility that will allow sending a text message to users on a switch?

Background: Various Microsoft OS's on workstations (95 through XP) running Novell Clients. Connected to Cisco 4006 switches. We're updating the switches software and want to notify clients before rebooting the switches.

I would like to know if there is a third party software or a Cisco feature I am unaware of that will notify just the workstations connected locally to the switch that it is going to go down and that they need to reboot.

Thanks for any help you can provide.
Mike13

 

[jneiberger]

I've never heard of anything like this. In order to do this, a tool would have to do the following:

1. Download the MAC address table from the switch
2. Download the ARP table from the router
3. Cross-reference the two tables to get the IP addresses of the users on a specific switch
4. Send messages using some sort of as-yet-unknown application to those IP addresses

A good programmer could come up with something in a day or so. However, I'm unaware of a tool already in existence that can do this for you automatically.

 

[PalmTest]

It is all being done already!!

Remember Tobias Oetiker with his wel known MRTG?
This same guy wrote a Perl script which handles the steps 1. 2. and 3. as suggested by jneiberger.

Take a look at

http://people.ee.ethz.ch/~oetiker/webtools/mrtg/pub/contrib/

and look for the script Cammer.
Read the cammer.readme.txt, install Perl, run the script and be surprised !!
(this guy Tobias is good!!)

Filter out the uplink (and/or Downlink) ports, and you know which MAC and IP address reside on which Switchport.
Now you have some scripting to do for yourself.
E.g. by using nbtstat -a <Ip Address> you can determine if a user is logged on at a certain IP Host, assuming they use Windows on their workstation.
Using the net send <logon name> command you can send a text message on the users desktop.