Software or PHP/PERL scripts for simple network management?

Tue Jun 19 20:26:08 UTC 2007

Many years ago I worked for a small Mom-and-Pop type ISP in New York  
state (I was the only network / technical person there) -- it was a  
very free wheeling place and I built the network by doing whatever  
made sense at the time.

One of my "favorite" customers (Joe somebody) was somehow related to  
the owner of the ISP and was a gamer. This was back in the day when  
the gaming magazines would give you useful tips like "Type 'tracert  
$gameserver' and make sure that there are less than N hops".  Joe  
would call up tech support, me, the owner, etc and complain that  
there was N+3 hops and most of them were in our network. I spent much  
time explaining things about packet-loss, latency, etc but couldn't  
shake his belief that hop count was the only metric that mattered.

Finally, one night he called me at home well after midnight (no, I  
didn't give him my home phone number, he looked me up in the  
phonebook!) to complain that his gaming was suffering because it was  
"too many hops to get out of your network". I finally snapped and  
built a static GRE tunnel from the RAS box that he connected to all  
over the network -- it was a thing of beauty, it went through almost  
every device that we owned and took the most convoluted path I could  
come up with. "Yay!", I figured, "now I can demonstrate that latency  
is more important than hop count" and I went to bed.

The next morning I get a call from him. He is ecstatic and wildly  
impressed by how well the network is working for him now and how  
great his gaming performance is. "Oh well", I think, "at least he is  
happy and will leave me alone now". I don't document the purpose of  
this GRE anywhere and after some time forget about it.

A few months later I am doing some routine cleanup work and stumble  
across a weird looking tunnel -- its bizarre, it goes all over the  
place and is all kinds of crufty -- there are static routes and  
policy routing and bizarre things being done on the RADIUS server to  
make sure some user always gets a certain IP... I look in my pile of  
notes and old configs and then decide to just yank it out.

That night I get an enraged call (at home again) from Joe *screaming*  
that the network is all broken again because it is now way too many  
hops to get out of the network and that people keep shooting him...

What I learnt from this:
1: Make sure you document everything (and no, the network isn't  
documentation)
2: Gamers are weird.
3: Making changes to your network in anger provides short term  
pleasure but long term pain.

---
Warren Kumari.
http://www.kumari.net

On Jun 19, 2007, at 2:05 PM, Valdis.Kletnieks at vt.edu wrote:

> On Mon, 18 Jun 2007 21:18:06 BST, Leigh Porter said:
>> Just out of interest, why are you looking at routing tables to  
>> find an
>> available subnet?
>
> If your predecessor wasn't quite as careful documenting  
> allocations, it can
> be useful to see if your paperwork says a /28 is dark, but you're  
> in fact
> routing traffic for it down some customer's link.  Then you get to  
> do two
> things:  (a) check if there's any *return* traffic and (b) call the  
> customer
> and ask if *they* think it's dark or not.  Hilarity ensues for some  
> combinations
> of answers...
>
> (And yes, I once had a co-worker looking for a free /24, found one  
> that was
> nice and empty except for smack dab in the middle, a route for a / 
> 28 that for
> no apparent reason pointed at an unused but registered static IP of  
> mine in the
> middle of our modem pool space.  After some digging, we remembered  
> that it was
> a work-around for when I had 2 IBM RTs at home, that did SLIP and  
> static
> addresses, but not NAT or DHCP, so my home net had some routing  
> workarounds
> that never got taken down when I replaced the 2 RTs with one box  
> that was happy
> to accept whatever address PPP handed it)
>

Life is a concentration camp.  You're stuck here and there's no way  
out and you can only rage impotently against your persecutors.
                 -- Woody Allen