Wide-Area Networks - CCIE Routing and Switching Exam Certification Guide - page 240

When the device wants to send an IP packet to another device, it sends an ARP request to the
ATM ARP server. If the destination device is already registered with the ATM ARP server, the
server sends an ARP response to the client. After the originating device has the ATM address of
the destination device, it can establish an SVC to the destination using UNI signaling.
If the ATM ARP server does not have an entry for the requested destination device, it sends a
negative response to the ARP client.
RFC 2225 uses LLC/Subnetwork Access Protocol (SNAP), as defined in RFC 2684, for
encapsulation of IP packets. LLC/SNAP encapsulation allows sharing of VCs. RFC 2225
specifies the use of AAL5 for transport of IP packets.
IP to VC Mapping
The following sections describe configuring an ATM switch router for CIA in an SVC
environment using NSAP addressing.
The ATM switch router can be configured as an ATM ARP client to work with an RFC 2225
ATM ARP server. Also, an ATM switch router can be configured to be the ATM ARP server and
act as a client.
To configure an ATM switch router as an ATM ARP client, enter the commands in Example 5-12.
Example 5-12 ATM ARP Client Configuration
router(config)# interface atm 0
router(config-if)# atm nsap-address
47.0091.8100.0000.1122.1123.1111.1111.1111.1111.00
router(config-if)# ip address 123.233.45.1 255.255.255.0
router(config-if)# atm arp-server nsap
47.0091.8100.0000.1122.1123.1111.2222.2222.2222.00
router(config-if)# exit
router(config)# atm route
47.0091.8100.0000.1111.1111.1111.1111.1111.1111 atm 0 internal
To configure an ATM switch router as an ATM ARP server, enter the commands in Example 5-13.
Example 5-13 ATM ARP Server Configuration
router(config)# interface atm 0
router(config-if)# atm nsap-address
47.0091.8100.0000. 1122.1123.1111.1111.1111.1111.00
router(config-if)# atm arp-server self
router(config-if)# ip address 123.233.45.2 255.255.255.0
To verify the configuration of the ATM0 interface, use the show atm arp-server command.
To verify the mapping of IP addresses to NSAP addresses, use the show atm map command.