How do you get a IP Address through DHCP when you dont have an IP adress to begin with?But yet you need a?

Question

IP address to being with!

I was told it like a chicken and an egg type of thing which came first!

Answer 1

You have a MAC address which asks the router for access and an IP address. If the MAC address is blocked it will never get an IP address.

Answer 2

The underlying protocol does not need an address, it broadcasts it's MAC address. The DHCP server simply listens for these broadcasts, and replies to the MAC with an offer of an IP address, if the machine acknowledges this it notes the address assignment. The reason we need IP is that there is no way to directly route a MAC beyond the local network.

Answer 3

no it's nothing like the chicken and the egg.

the Media Access Layer is communicating with the DHCP server. All network cards have a unique MAC Address

the whole process on power on or activation of the network card is

the card sends out a DHCP request with a broadcast packet containing its source MAC address.

All DHCP or bootp (for the fossils) will answer up with a DHCP offer. the client will take the first received and issue a DHCP ACK (acknoledgement) or a DHCP NACK(negative acknowledgement)

if no offer is recieved in a certain amount of time the process is repeated.





You can read up on the OSI model if you are interested in learning more.

Answer 4

Likely, no. Internet service providers assign IP (Internet Protocol, for clarification) addresses when you connect to their server. Since they never have enough IPs for every customer, the IP is "dynamic", meaning that it can and will change. You usually have to pay extra for a "static" IP, which does not change. Even my cable connection, which is always on, changes about every 6 months. A dialup connection, which is not online until you dial in, may change every time you dial in. They have to let someone else use that number when you are not using it. IP addresses are assigned automatically by the Internet Service Provider's (ISP) DHCP server.