Found the same question at linuxquestions.org. So maybe that could help.
Excerpts from the link:
Question: Does anyone know of any network mapping tools for Linux (Ubuntu 8.04) similar to The Dude?
Answers:
1. There are several things that might do what you want (I have no
knowledge of 'The Dude' apart from the link that you posted, so I've
assumed anything that does network mapping might be what you want and
posted a few from the first few pages on sourceforge):
Nagios/Nagvis
Mila_Ajax_Map
Safe Mapping and Reporting Tool (SMART)
Network Scaner
NMap Console
Oggle Network Mapping and Display Tool
Prime
CartoReso
OpenMapper
OSPF network visualizer
netfuse
Ajax Network Map
Network Administration Visualized
Advanced Network Topology and Inventory (?) ...
If, however, you want an easy life, you should probably check out the
packages that your distro offers. Depending on the repos that you have
enabled, you should get a list something like this:
lanmap
netdude
netmrg (?)
zabbix (?)
Looking at the names, netdude seems an attractive prospect, as the
possibility is strong that one of these dudes was inspired by the
other, in some way.
2. Lanmap is similar to The Dude; it creates a graphical layout of
your network.
Also after a little bit of Googling found that lanmap has been abandoned but there is a lanmap2.
