Asante Technologies 3624/48 user manual Establish Address Resolution

/19	32 Class C		8,192 Hosts
/18	64 Class C		16,384 Hosts
/17	128	Class C	32,768 Hosts
/16	256	Class C OR 1 Class B	65,536 Hosts
/13	2,048 Class C		524,288 Hosts

6.1 Establish Address Resolution

A device in the IP can have both a local address (which uniquely identifies the device on its local segment or LAN) and a network address (which identifies the network to which the device belongs). The local address is more properly known as a data link address because it is contained in the data link layer (Layer 2 of the OSI model) part of the packet header and is read by data link devices (bridges and all device interfaces, for example). The more technically inclined will refer to local addresses as MAC addresses, because the Media Access Control (MAC) sub-layer within the data link layer processes addresses for the layer.

To communicate with a device on Ethernet, you first must determine the 48-bit MAC or local data link address of that device. The process of determining the local data link address from an IP address is called address resolution. The IntraCore 3624/48 software uses the Address Resolution Protocol (ARP) for address resolution. ARP is used to associate IP addresses with media or MAC addresses. Taking an IP address as input, ARP determines the associated media address.

Once a media or MAC address is determined, the IP address/media address association is stored in an ARP cache for rapid retrieval. Then the IP datagram is encapsulated in a link-layer frame and sent over the network.

47 Asante IntraCore IC3624/48 User’s Manual