[CLUE-Tech] Easiest DHCP

[Jeremiah Stanley]

> I took a look at that article.  I'm curious, how does the ISP detect
> nat'ing, and how would they determine how large the network behind the
> firewall is?

As root run: nmap -O <yourhosthere>

This will give you OS fingerprinting information. Winders and all its 
flavors seem to have a pretty consistent fingerprint and even the Norton 
and BlackIce firewalls (oh, man are these cheesy) appear to have a 
consistent fingerprint. So I'd assume they could do massive port scans and 
see if you were doing this and just try and match what OS you told them 
you were running. I dunno, seems flaky to me but I've worked for a 
corporate ISP and after that, nothing seems stupid or outlandish that they 
do. It is all just typical. (Man, I sound bitter don't I!)

Someone mentioned a MAC address, MAC's don't get passed outside of the 
physical ethernet layer so this wouldn't do too many ISP's a greasy damn. 
Now dhcpcd does send the MAC out to the ISP but you can set that using the 
-I flag to use your own string (like grab the MAC off the crappy NIC they 
give you, which I didn't get one so did they just collect it when I first 
used it?). 

I personally would call NAT'ing and firewalling your network a service to 
your ISP. It is expensive and takes some wet ware to allocation IP's in a 
sensible manner and by only using one per household they are saving money. 
I'd be willing to venture that most cable companies and ISP's use consumer 
apathy/lack of knowledge to charge close to six bucks for multiple IP's. A 
friend of mine has six computers he does that with and it almost doubles 
the cost of his service. I assume by charging for this extra IP, they 
assume that it is a 'support cost' that they will charge you for needing 
their tech support to get DHCP to work with winders (enabled by default).

There doesn't seem to be a prolific level of hardware NAT devices out 
there. I would think that an 802.11b NAT router for the home would be a 
hot seller. Plug it into the ISP's router and you can take your laptop 
anywhere in the house. But I assume that the ISP wants to support winders 
instead of some other device. They could eliminate their support costs if 
instead of giving out the cheapest possible cable router (if you can call 
it a router) and send out a network NAT device in it's place. Most of 
their customers would be tickled pink to "not mess with the damn 
computer".

But I'll get off my soapbox now... :)

JStanley
-- 
Love is a snowmobile racing across the tundra and then suddenly it flips over, 
pinning you underneath. At night, the ice weasels come.  - Matt Groening