Sun Microsystems 3U - Manual (Page 89)

Chapter 7 Classical IP and LAN Emulation Protocols 67
ATM Address Registration Daemon ( ilmid )
Address registration with a switch is controlled by ilmid . When an ATM interface
is brought up at boot time, ilmid is also started. ilmid then begins an exchange of
messages with the switch: relaying local address information (the seven-octet ESI
and selector) to the switch and receiving the 13-octet network prefix information
from the switch.
The default local address that is registered with the switch at boot time consists of
the network prefix provided by the switch, the MAC address assigned to the local
interface, and the default selector for that interface (usually 0). Additional addresses
are registered in two different ways.
aarsetup(1M) and lanesetup(1M) register
additional local addresses that may appear in aarconfig(4) and laneconfig(4) ,
respectively. You can also use atmreg(1M) to register addresses, unregister
addresses, and check the status of any address.
Classical Internet Protocol
For ATM to work transparently under IP, an IP address must be resolved to an ATM
address and a connection to that destination must be established. Classical IP does
this via a database of IP/ATM address pairs that is either provided by an ATM ARP
server that is accessible to all hosts on the subnet, or is maintained locally in each
host.
ATM Address Resolution
Traditional TCP/IP and UDP/IP applications use IP addresses for communicating to
a destination. For these applications to run like traditional applications, IP addresses
need to be resolved into ATM addresses. The ATM address then signals to establish
an ATM connection to the destination. An ATM connection in turn is represented by
a VPI/VCI. The host must use this returned VPI/VCI to send packets to the
destination that represents the ATM connection.
ATM address resolution, also called ATM ARP, follows RFC 1577, the classic draft
that describes the ATM ARP process.
RFC 1577 assumes the existence of an ATM ARP server on every subnet. Every client
on the subnet communicates with the ATM ARP server to derive the destination’s
ATM address from its IP address. The ATM ARP server holds the IP-to-ATM address
information for all hosts in the ATM subnet. It is likely that initial ATM
configurations will not rely on dynamic ATM address resolution because it requires
the presence of an ATM ARP server on every subnet. Also, there are no specified