Brandeis University IOS TFTP Server
Copyright 2008 Brandeis University

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

== How it works ==

Cisco routers provide a rich SNMP API, but much of their functionality is
accessible only through the interactive command line. It may be convenient
to automate tasks that require CLI functionality, but it's a pain to use
expect-style automation.

Fortunately, many Cisco routers support the hostConfigSet OID in the
OLD-CISCO-SYS-MIB. This OID allows you to cause the router to configure
itself using a file fetched from a TFTP server.

This package contains a "fake" TFTP server meant to be used with
hostConfigSet. It doesn't serve real files from a filesystem - instead it
uses the requested filename to determine the IOS commands to return.

Currently only "block-<IP address>" and "unblock-<IP address>" are
implemented. They add and remove null routes to the specified IP, using the
following IOS commands:

ip route <IP address> 255.255.255.255 null0
no ip route <IP address> 255.255.255.255 null0

== Requirements ==

* UNIX-like system (developed on RedHat Linux)
* Perl with IO::Socket and Sys::Syslog
* Border router that supports OLD-CISCO-SYS-MIB

== Setup ==

1. Copy ios-tftpd.pl somewhere, like /usr/local/sbin.

2. Optionally copy ios-tftpd.init into your SysV init directory:

# cp ios-tftpd.init /etc/init.d/ios-tftpd

On systems with chkconfig, you can then enable the service with:

# chkconfig --add ios-tftpd
# chkconfig ios-tftpd on