Scotty - Tcl Extensions for Network Management Applications

Jürgen Schönwälder, Simple Group, University of Twente

Overview

Scotty is the name of a software package which allows to implement site specific network management software using high-level, string-based APIs. The software is based on the Tool Command Language which simplifies the development of portable network management scripts. The scotty source distribution includes two major components. The first one is the Tnm Tcl Extension which provides access to network management information sources. The second component is the Tkined network editor which provides a framework for an extensible network management system.

Tnm Tcl Extension

The Tnm Tcl extension allows to access network management information sources from within Tcl. The Tnm extension supports the following protocols:

SNMP (SNMPv1, SNMPv2c, SNMPv2u including access to MIB definitions)
ICMP (echo, mask, timestamp and udp/icmp traceroute requests)
DNS (a, ptr, hinfo, mx and soa record lookups)
HTTP (server and client side)
SUN RPC (portmapper, mount, rstat, etherstat, pcnfs services)
NTP (version 3 mode 6 request)
UDP (send and receive UDP datagrams - no channels yet)

Additional commands are provided to simplify the implementation of network management applications:

The netdb command allows to access local network databases (host names and IP addresses, service names and number, network names, protocol names, Sun RPC service names).
The syslog command allows to send messages to the local system logging facility.
The job command simplifies the implementation of monitoring or control procedures that need to be scheduled at regular intervals.

The Scotty distribution includes a couple of example scripts that show how you can write scripts to automate your site or network specific management tasks.

A slightly more complex graphical SNMP MIB browser example allows you to explore MIB data. This browser is useful as an ad hoc management tool as well as a utility while developing management applications.

The Tnm Tcl extension is used by vendors of SNMP based management software to implement regression test suites for their products. Tests for management applications are straight forward to implement since the Tnm extension can run as a dual role entity allowing you to prototype SNMP agents by writing Tcl scripts.

Tkined

The Tkined network editor provides a framework for an extensible network management platform. Extensions are usually written in Tcl based on the Tnm extension. This allows to integrate site or network specific management tools at very low costs. The Tcl API allows to control every aspect of the editor which makes it possible to even automate standard user interactions with Tcl scripts.

Network maps can be maintained by using the editing features provided by Tkined or using automated tools. The source distribution contains applications to discover IP networks, to support the network layout process, to troubleshoot IP networks using SNMP in combination with other standard tools (e.g. traceroute) and to monitor network status using SNMP or selected SUN RPCs.

There are also some vendor specific applications that take advantage of the enterprise specific management capabilities of their products.

Getting Scotty

The Scotty package is freely available as a source code release. It compiles on all major UNIX platforms. You need a C compiler, Tcl/Tk and the usual utilities (e.g. make, sed) to compile and install Scotty. Scotty comes with a GNU autoconf configure script to simplify the compilation and installation process.

The latest version of the Scotty source code (1.4 MB compressed tar archive) is available from several FTP servers:

ftp.ibr.cs.tu-bs.de (Germany - primary server)
ftp.cs.utwente.nl (The Netherlands)
sunsite.doc.ic.ac.uk (Great Britain)
netlab-c.mscs.mu.edu (USA)
ftp.ibp.fr (France)
ftp.sunet.se (Sweden)
ftp.inf.utfsm.cl (Chile)
NCTUCCCA.edu.tw (Taiwan)

Documentation

The primary source are the manual pages that are distributed with Scotty package. An HTML version of the current manual pages is also available online:

Scotty(1) A Tcl shell including the Tnm extensions.
Tkined(1) An Interactive Network Editor based on Tk.
Tnm(n) Tcl extensions for network management applications.
dns(n) Query the Domain Name System of the Internet.
http(n) Send and process HTTP requests.
icmp(n) Send ICMP messages to hosts on the Internet.
ined(n) Access and manipulate tkined objects.
job(n) Invoke Tcl procedures at regular intervals.
mib(n) Load and query SNMP MIB definitions.
netdb(n) Access the local network databases.
ntp(n) Retrieve control variables from NTP peers.
snmp(n) Send SNMP messages to devices on the Internet.
sunrpc(n) Call and probe selected Sun RPC services.
syslog(n) Write messages to the system logger.
udp(n) Send and receive UDP datagrams.

Additional information about selected topics is available online:

Mark Newnham:
Getting started with Tkined
January 1997.
J. Schönwälder, H. Langendörfer:
Tcl Extensions for Network Management Applications
Proc. 3rd Tcl/Tk Workshop
Toronto (Canada), July 1995.
J. Schönwälder, H. Langendörfer:
Eine Netzwerkmanagement-Plattform basierend auf der Tool Command Language (Tcl)
GUUG Frühjahrsfachgespräche
Köln, March 1995. (in german)
J. Schönwälder, H. Langendörfer:
How To Keep Track of Your Network Configuration
Proc. 7th Conference on Large Installation System Administration (LISA VII)
Monterey (California), November 1993.

Help and Assistance

We receive several questions per day about the Scotty package which we answer as good as we can. We collect frequently asked questions into a Scotty Frequently Asked Questions document in order to reduce the number of questions we have to answer. Please check this document before sending us a question.

If you have problems to install scotty on your UNIX system, please consult the file unix/porting.notes. An up-to-date version of the porting.notes file is available via this WWW page.

There is a mailing list where scotty users can get help or exchange tips and tricks. New releases and bug fixes are also announced on this list. You can send a message to all subscribers of the mailing list by using the email address

tkined@ibr.cs.tu-bs.de.

For subscribing to this mailing list, or for information how to use the list, send email to

tkined-request@ibr.cs.tu-bs.de.

A sorted archive of this mailing list is available for the years 1994, 1995, 1996, 1997. A full text indexed searchable archive is also available (starting October 1995).

Contributed Software

Several people have written software based on the scotty package. Some of them make their scripts freely available. The list below lists user contributed software that is not part of the scotty distribution:

Several small and useful scripts written by Jarle Fredrik Greipsland.
A scotty script written by Ethan Gold that keeps track of network nodes and notifies people when something is amiss.
hphubwatch is a Tkined tool written by Doug Hughes to look at HP hubs.
hphubtools is another Tkined tool written by Ethan Gold to look at HP hubs.
George Eddy has written a visual front end to Internet Routing Registry (IRR) analysis tools.
Robert Premuz has written a UNIX SNMPv2c agent based on the Tnm extension. The agent can be used for monitoring some states of a UNIX system (users, user groups, process, memory, and file systems).
Internet network connectivity monitoring graphs generated from the Scotty package using the map-generator script.