http://www.cisco.com/en/US/docs/switches/lan/catalyst3750e_3560e/software/release/12.2_55_se/configuration/guide/swadmin.html#wp1195372
Managing the ARP Table
To communicate with a device (over Ethernet, for example), the software
first must learn the 48-bit MAC address or the local data link address
of that device. The process of learning the local data link address from
an IP address is called address resolution.
The Address Resolution Protocol (ARP) associates a host IP address with
the corresponding media or MAC addresses and the VLAN ID. Using an IP
address, ARP finds the associated MAC address. When a MAC address is
found, the IP-MAC 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. Encapsulation of IP datagrams and ARP
requests and replies on IEEE 802 networks other than Ethernet is
specified by the Subnetwork Access Protocol (SNAP). By default, standard
Ethernet-style ARP encapsulation (represented by the arpa keyword) is enabled on the IP interface.
No comments:
Post a Comment