
Understanding Classical IP over ATM Concepts
114056 Rev. A 3-3
Figure 3-2. IP Logical IP Subnet
ATM Address Resolution
An address resolution protocol defines a mechanism that enables an IP router to
use the IP address of a network device to learn the physical address of that device.
An Ethernet LAN uses ARP as its address resolution scheme. A LIS uses an
address resolution scheme called ATMARP as defined by RFC 1577.
On a LAN, defined as a broadcast medium, a router obtains the physical address
of a network device by broadcasting an ARP request. In a LIS, which uses a
nonbroadcast ATM medium, a router sends an ATMARP request to an ATMARP
server.
Each IP interface on the LIS opens a VC to the ATMARP server and registers its
IP address and ATM address (Figure 3-2). Using this information, the server
builds and maintains a table that maps LIS IP addresses to ATM addresses.
Router A
Host
C
Host
A
Host
B
ATM0037A
ATM network
ATMARP client
Router A
ATMARP server
Key
SVC supporting ATM LIS
Comentários a estes Manuais