Reply #24: DHCP Server

[tinfoil_beret]

Assuming the computer did not have a physical or wireless connection to a network, the computer has a DHCP server, which assigns IP addresses to clients dynamically. Futhermore, the message in the original posts shows that the DHCP server responded to a request for a lease for 192.168.2.4 for the device with the MAC address 0001A8C00100502C070C07. If the computer did not have a connection to another computer, we could assume that the MAC represents a LAN adapter on the computer.

For those unfamiliar with dynamic and static IP addresses, a DHCP server relieves a system administrator from manually assigning static IP addresses by dynamically assigning IP addresses from a range of addresses. When the administrator physically (or wirelessly) connects a new computer to the network and sets it to request an IP address dynamically, the DHCP server will automatically assign an unused IP address to the computer.

As I recall, a Windows computer would not have a DHCP server runniing automatically. Just imagine if every Windows installation automatically started a DHCP server. In such a case, anyone setting up a home network would need to disable all but one DHCP server, because multiple DHCP servers would clash trying to manage their pools of available IP address.

However, as I recall, a Windows computer with networking enabled will default to dynamic-IP addressing, ie. it will by default expect to retrieve an IP address from a DHCP server when the user connects it to a network, eg. with an ethernet cable.

Assuming that the computer mentioned in the original post did not have a physical (or wireless) connection to a network, the computer has a DHCP server running on it. I can see no reason for running a DHCP server on this computer.

Note: Most routers I have used, by default use the class C network 192.168.0.0 or 192.168.1.0 with DHCP enabled. The only router I have seen using the class C network 192.168.2.0 by default was a wireless router, which used DHCP by default. Curious. How do we know that this computer did not have an 802.11b (WiFi) adapter?

Of course, the computer might communicate with the "digiboard" over TCP/IP, but without knowing anything about this digiboard I can't come to any conclusions about it.