What is the major diffrence between RARP and DHCP? (or am I just stupid now) They both assign IP addresses don't they?

Plugged RARP into dogile.com and came up with a bunch of links. Try http://www.cis.ohio-state.edu/cgi-bin/rfc/rfc1931.html

RARP doesn't assign IP addresses, it is used to discover what IP address a machine is using. DHCP is dynamic in that the IP addresses changes as it is assigned, RARP involves a static address that often is not recorded to a node (as in a dumb terminal) but recorded in a RARP server.

A RARP server assigns IP addresses to clients just like a DHCP server however DHCP has the ability to providec extra info such as subnet mask, gateway,nameserver, wins server, just about any network service.

Actually, only one of the two assigns IP addresses and thats DHCP(don't know what went on in the posts above). ARP and RARP operate at the data link layer where as DHCP operates at the IP layer. RARP stands for "Reverse Address Resolution Protocol." Its partner protocol is ARP which stands for, you guessed it, "Address Resolution Protocol." RARP and ARP are used to map hardware addresses (MAC addresses) to network addresses (IP addresses)and vice versa. Normally, you won't encounter ARP unless you wanna know your MAC address (type "arp -a" at the command prompt). This protocol mainly comes in when a machine has multiple NICs like a router.

I'll give you some credit, RARP does work at the Data Link layer, but don't confuse yourself about what they're both designed to do. Just because DHCP is encapsulated in a UDP datagram, and RARP encapsulated directly in a data link frame makes no difference. They are both used to assign an IP address from a server. I think your getting confused because you probably understand the use of ARP (mapping a logical address to a physical address but are not understanding why RARP is needed.(well done RARP is ARP with an R) Whenever a host or router has an IP datagram for the reciever it will know the IP address but may not know the physical MAC which is needed to actaully send the datagram on it's way (ARP to the rescue). This will happen anytime a host/router has an IP datagram for delivery.... however The only time a host/router will need to do the reverse (map a physical address to a logical address) is when it has no knowledge of what its own logical address is meant to be. Such as when a diskless workstation is powered up. RARP Servers provide this information. And no, there is no such thing as an ARP server. (well actually you can have an ARP proxy but that will only confuse you more).