DHCP on wireless network

[rairai]

Hi,

When a DHCP server assigns an IPAQ an IP address over a wireless network, how does the IP addresses get stored, is it in a database?
And how can we identify which IPAQs have which IP address?
And it seems anyone can go on to the network if they come within the signal range? Can we have the user enter a name and password to identify the rightful user on the network?

Thanks...

[stevemw]

I don't know if this will answer all of your problems but consider the following in a wireless network:

1. your AP should have a unique and distinct SSID (create it using upper, lower and number characters).

2. you should use some level of Wireless Encryption Protocol so that device can only connect to the AP after supplying the shared password.

3. you should configure the dhcp server to provided ip addresses outside of the default range; if items 1 and 2 are satisfied then this item does not matter so much.

4. to enable network authorization you must have a domain controller present on the network and the iPAQ has to be configured in a way where it can join the domain. "Join" is used rather loosely here because you will be presented with a username/password prompt when you attempt to access the network and connection will be allowed if you use an existing domain account; the name of the ipaq should be added as a computer in the domain.

Generally if you can configure the properties of your network adapter to match those of the other machines on your network (IP address and network mask in the same name network, same default gateway), you should be able to communicate with all machines in the network and surf the web; if you do not configure a default gateway, then the iPAQ will not be able to surf the internet.

[rairai]

Thank you, you have given me something to think about.

For point number 3: Since DHCP provides a default range, how do we come up with our own range of ip addresses. Is there anything to consider?

[stevemw]

The following is a crude and simple description of defining an internal network.

First decide how many network addresses you need (multiples of 8 minus 2).

Then decide which range. there are 3 private network ranges 10.0.0.0, 172.16.0.0, and
192.168.0.0. These addresses are never assigned to Internet hosts and
are usually unroutable unless specific routing information is defined in the
local routing tables.

Then determine the network starting address.

For example, to define a network with 32 (30 addressable) hosts that
includes the address 10.2.16.84:
a. network mask 255.255.255.224 defines 32 hosts
b. using a caculator, find 84 AND 216: this gives you your base address of 64
c. assign addresses 10.2.16.65 thru 10.2.16.94 to the DHCP server with a network
mask of 255.255.255.216 (or configure these addresses statically.

[rairai]

Thank you for that.

[Mark D. Rejhon]

Might be a nitpick, but :)

WEP means "Wired Equivalent Privacy" .... but is commonly called "Wireless Encryption Protocol" It's proven to certainly not be the former as it is supposed to be called, but the latter is more accurate.

Also, most routers (Common DSL/cable sharing boxes and access points, are typically routers of sorts too) have a starting address that ends in .1 and you are using a private network....

If you are network-challenged, concentrate on the encryption -- that would be the most important privacy concern for you. Then follow simple rules for people who don't know what they are doing: Use a private network starting address ending in a ".1" (A popular one is 192.168.0.1, so you can use that.). A netmask of 255.255.255.0 is a catch-all that's easy to setup even if you do not need over 250 Internet devices. Then you never have to worry about IP addresses or math calculations. Let DHCP do the rest - i.e. never have to worry about IP addresses again, it will be in a range of up to approximately 250 addresses, though most home routers can only automatically manage 32 at a time. Most home people don't have 32 Internet devices anyway. On those routers they will only use 192.168.0.1 through 192.168.0.32 even when using a netmask 255.255.255.0 netmask (if you're clueless or lazy about doing netmask calculations). Then simply use the router's statistics/logging facility to determine who has connections. Though most Net-sharing router devices will only give you a barebones list of who's connected to the router.

If you are a network administrator you will be picky over the details and should follow stevemw's recommendations.

[rairai]

How do we know if the IPAQ or a device is DHCP enabled?
And is the DHCP server needed to be installed to have this dynamic addressing?

Thanks...

[stevemw]

One of the steps involved in configuring the wireless adapter is specifying whether it has it's own unique IP addess or must request an IP from the network.