Re: [tlug] network diagrams, spreadsheet, or database

[Alain Hoang <hoanga@example.com>]

Micheal E Cooper wrote:

> Our network documentation is way out of date, so I was about to use Dia to
> make new network diagrams. I found this link, which though out of date
> compares different network diagram tools:
> http://www.linuxdevcenter.com/pub/a/linux/2001/02/15/LinuxAdmin.html
>
> Since none of these seems ideal, I was wondering what other people use. I
> have also talked to folks who dismiss network diagrams in favor of
> spreadsheets/ databases.
>
> I would just like to make some up-to-date documentation of the network so
> that someone can come in and fix things if something happens when I am
> away. I will be going back to the US for the first time in 9 years, and I
> want to make sure that there are no catastrophies while I am gone.
>
> Any software recommendations or alternatives?
>
>  
   Thanks for the link.  I think your answer would partially depend on 
the size of your network.  For small to medium sized networks I think 
you can get away with using Dia just fine.  For larger networks the 
hierarchical views that the other tools seem to offer would be quite 
beneficial.  I have used Tkined myself but I found its UI a little too 
quirky for me and I ended up doing many undesired actions (such as 
deleting gateways I didn't want deleted) when trying to build a useful 
network map with it.  I have tended to use Dia most of the time since I 
found it simple enough to use and it exported into enough different 
formats that I was satisfied with.  One thing I would think about when 
choosing a tool is how easy would it be for others in the company to be 
able to access the diagram.  If you use hierarchical views heavily you 
can either export everything to a bunch of image files or make sure 
someone else has access to program <blah> so they can easily view the 
network diagram.
   When it comes to network documentation, my personal thoughts are you 
can NEVER have enough and I always seem to have the wrong set of docs 
for the problem at hand (necessitating the need to update the outdated 
docs).  If you can manage, I would have both a network diagram and a 
database/spreadsheet listing all the important information for your 
network so anyone can locate this information quickly without having to 
crawl under Yamada-san's desk to find workstation A actually has an IP 
address of 192.168.0.35 rather than .34.  And of course the underside of 
Yamada-san's desk hasn't been dusted in eons making the job just that 
much enjoyable. :-)
  I would never discount a network diagram since it can give someone 
who is unfamiliar with a network a very good birds-eye view of the 
network in a very short amount of time.  I'm not sure what to think of 
people who eschew network diagrams.  They're probably too elite for me  
:-).  However, diagrams can become burdensome if you want to include 
every single stinking workstation in the diagram in a network with 
hundreds of workstation.  At that point you might be adding too much 
visual noise to make out much of anything.  Creating a good set of 
network diagrams that are useful in times of crisis is a decent balance 
of enough detail without dropping out critical information.
   Spreadsheets/databases are very good tools for keeping track of IP 
addresses, MAC addresses and all those other types of network 
information that are not easily captured in a visual form.  I presume 
with some fancy structuring of your data you could probably 
auto-generate a nice logical diagram of your network given the 
information in your spreadsheet but then that requires another tool.  
Personally, I'm wary of such tools since I'm not thinking of neat-o 
tools when firefighting, just the set of tools for getting the job 
done.  If you have a nice reliable database lying around, then it would 
make sense to dump all these tabular types of information into that 
database.  Otherwise, a set of spreedsheet documents or text files in 
tabular form would be sufficient.
Cheers,
Alain