pc technician who's boss won't explain things to him ..

*edited, i answered some of my own questions*

255.255.255.0 = 254 possible IP's
255.255.255.240 = 254 possible IP's .. *edit* just in 16 different scopes/networks *edit* ??!!?? this one is key for me to understanding how our network is suppose to run *edit* 240 sub = 1111 0000 which gives me 15 IP's to use in each (14 really, because i've got to use 1 for broadcast in each sub network) .. so, sec, gotta read more (note, i kinda have to write down as i go along .. it's that whole male syndrome thing about not being able to do 2 things at once :lol: *edit*

10.168.161.x (where x = our LAN or available IP's to our customers)

is the class A address part of our provider's "forest" and by subnetting it down to 240, they're providing a total of 16 subnetworks to use for us .. each sub will have 14 IP's in it

the provider stated we should have enough IP's to get 254 customers onto our network .. I don't see how that's possible?? if it's subnetted down like that .. we will only be able to support 224 IP's, no?? I'm going to re-read/skim the networking guide again .. see if maybe i missed something ..

I missed the main action on this post (wow where was I, it jumped to two pages before I saw it !! )

But yeah, it sounds like your provider owns a class A, giving him lots of IPs, and he's given you a (rather small) subset of those. I assume out of those you'll be giving a few out to subscribers or something...

Just want to correct one thing, you said :

10.168.161.x (where x = any 16 numbers i choose minus the server IP and the router's LAN IP giving me a possible 14 IP's to use)

You get 14 IP's out of the .240 subnet, because you need to subtract two -
1. The subnet address
2. The subnet broadcast address.

After you have those 14, two will go on your server and router.. leaving you with 12.

The math behind it is fairly simple. The formula is 2 raised to number of host bits -2.
So heres how we work it out :

10.168.161.0
255.255.255.240

240 = four host bits (convert it to binary and count the zeros)
Thus available IPs are

(2 ^ 4) -2 = 14

you get 14 after excluding:
a. 10.168.161.0 - the subnet address
b. 10.168.161.15 - the subnet broadcast address
The valid range is 1-14

Keep in mind I've shown you the calculation only for the first subnet.

Don't confuse valid IP's with valid networks... each SUBNETWORK can have 14 IPs in it.

Read over the section on subnetting specifically. Its given much better there (I can't explain it like Chris does !)

Glad you like the site, and don't sweat it if they don't teach you stuff at work, you can learn SO much from these sites..

and just to let you in on something.. alot of people don't actually understand subnetting -- they know the concept, but just fake knowing why a particular mask is chosen.... perhaps your boss is one of those people.. that might explain his reluctance to show you

The best thing you can do is break your head over IP addressing while you're still learning the basics.. you will never regret it.


Cheers,


[btw if that subnet math is wrong, forgive me, I just spent the last half an hour setting ACLs where they make everything work backward lol]

so basically .. i'll have to setup my DHCP scope exactly like you posted on page one .. since we are forced to use the 240 subnet ..

cool, epiphany! .. assuming my ramblings are correct? .. heh, anyways, back to reading

Got the subnetting figured out ? Cool ! Yknow, you should print out the subnetting pages and keep em around as a reference.. just when you wanna clarify something.

Btw I have this strong urge to change 'pc technician' in your post subject to 'budding network engineer' you deserve it for wanting to learn more.

Hope we've helped you out.

"Don't confuse valid IP's with valid networks... each SUBNETWORK can have 14 IPs in it."

that's where i was getting thrown for a loop .. i was thinking that the 240 sub was limiting us to only being able to use 14 IP's total for our network .. ie, the other 15 scopes were non existant in my head and i was only comprehending the first scope of ip's from 1-14 ..

note, i do alot of writing/editing posts as i read/re-read the material .. i generally do edit post because it cuts down on the spam i create

** new - also, since in my test setup i'm making .. since i'm forced to use a 240 SM breaking my IP's up into 16 subnetworks .. i'll be spending the next few minutes reading sub routing and communications .. i'll be making edits to this post i'm sure, if i don't understand something ..

** ok, 1. how many IP addresses can i bind to 1 NIC ? 2. i am given only 1 router IP number which in turn is my GW .. sec, lemme draw a diagram of what i have .. brb

www.angelfire.com/blues2/raggedy_hobo/im.../network_diagram.jpg

so basically .. in theory, i should be able to create 16 different scopes using the DHCP tool in W2k .. each scope will contain 14 IP's to which will be assigned to the customers ( i will exclude some scopes because of the IP's required to be static)

how do i specify which customers get placed into which scope .. and, how do i use just 1 LAN router IP to talk to all 16 different sub networks? (more reading required :lol: )

*edit* mind you .. i have 0 control over the router provided .. do i need to put another router in between NS1/NS2 and our customer network? granted, our clients don't need to be able to "see" or share files with each other .. but, i do need all of them to be able to see the server/cisco router .. but how do i do that with only 1 gateway (which is the LAN side of the cisco router, correct?) will re-read the subnet routing and communications *edit*

*edit* is NS1 now acting as a gateway then?? and if so .. i suppose i have to set NS1 up to for 16 different gateways?? wait, no, i'll have to have a router connected to a hub .. i'll then have to configure the router to support 16 gateways .. but, if that's the case, shouldn't the main cisco router do that for me?? the providers of the router said they had 100% full control over it and that we had 0 .. so, since they prescribed the 16 subnetworks, they should have configured there router to support 16 different gateways, correct?? in theory right??