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This chapter describes how to configure IP over Asynchronous Transfer Mode (ATM) on the LightStream 1010 ATM switch. The IP-over-ATM connection can only be used to manage the ATM switch.
This chapter includes the following sections:
This section describes configuring a port on a switch to allow a classical IP-over-ATM connection to the switch CPU.
The following sections describe configuring the ATM switch in either a switched virtual circuit (SVC) or permanent virtual circuit (PVC) environment:
This section describes classical IP over ATM in an SVC environment. It requires a network administrator to configure only the device's own ATM address and that of a single ATM Address Resolution Protocol (ARP) server into each client device.
Figure 13-1 describes the steps needed to set up a classical IP-over-ATM connection between LightStream 1010 ATM switch client A and client B.

Step 1 The initial IP packet sent by client A triggers a request to the ARP server to look up the IP address and the corresponding ATM address of client B in the ARP server ARP table.
Step 2 The ARP server sends back a response to client A with the matching ATM address.
Step 3 Client A uses the ATM address it just obtained from the ARP server to set up an SVC directly to client B.
Step 4 When client B replies with an IP packet to client A, it also triggers a query to the ARP server.
Step 5 Once the connection is known to both clients, they communicate directly over the SVC.
In Cisco's implementation, the ATM ARP client tries to maintain a connection to the ATM ARP server. The ATM ARP server can tear down the connection, but the client attempts once each minute to bring the connection back up. No error messages are generated for a failed connection, but the client will not route packets until the ATM ARP server is connected and translates IP network addresses.
For each packet with an unknown IP address, the client sends an ATM ARP request to the ARP server. Until that address is resolved, any IP packet routed to the ATM interface causes the client to send another ATM ARP request.
The ATM switch can be configured as an ATM ARP client to work with any ATM ARP server conforming to RFC 1577. Alternatively, one of the ATM switches in a logical IP subnet (LIS) may be configured to act as the ATM ARP server itself. In that case, it automatically acts as a client as well. To configure classical IP and ARP in an SVC environment, perform one of the following tasks:
In an SVC environment, configure the ATM ARP mechanism on the interface by performing the following tasks, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | interface atm 2/0/0[.sub_inter #] | Select the interface to be configured. |
| 2 | atm nsap-address nsap-address | Specify the NSAP ATM address of the interface. |
| 3 | ip address address mask | Specify the IP address of the interface. |
| 4 | atm arp-server nsap nsap-address | |
| 5 | exit | Exit interface configuration mode. |
| 6 | Configure a static route through the switch to the CPU interface. See the following note. |
| 1First 19 bytes of the NSAP address. |
The following example shows how to configure CPU interface 2/0/0 of client A, in Figure 13-1, using the NSAP address:
Client A(config)# interface atm 2/0/0 Client A(config-if)# $dress 47.0091.8100.0000.1111.1111.1111.1111.1111.1111.00 Client A(config-if)# ip address 123.233.45.1 255.255.255.0 Client A(config-if)# $dress 47.0091.8100.0000.1111.1111.1111.2222.2222.2222.00 Client A(config-if)# exit Client A(config)# $0.0000.1111.1111.1111.1111.1111.1111 atm 2/0/0 internal
In order these commands:
1. Identify CPU interface 2/0/0 for configuration.
2. Configure the interface as an ATM ARP client with NSAP address 47.0091.8100.0000.1111.1111.1111.1111.1111.1111.00.
3. Configure the IP address as 123.322.45.1 with a subnet mask of 255.255.255.0.
4. Configure the ARP server NSAP address as 47.0091.8100.0000.1111.1111.1111.2222.2222.2222.00.
5. Exit interface configuration mode.
6. Configure an internal static route with an NSAP address of 47.0091.8100.0000.1111.1111.1111.1111.1111.1111.00 to ATM interface 2/0/0.
The following example shows how to configure CPU interface 2/0/0 of client A (Figure 13-1), using the ESI:
Client A(config)# interface atm 2/0/0 Client A(config-if)# atm esi-address 0041.0b0a.1081.40 Client A(config-if)# ip address 123.233.45.1 255.255.255.0 Client A(config-if)# $7.0091.8100.0000.1111.1111.1111.2222.2222.2222.00 Client A(config-if)# exit
In order, these commands:
1. Identify CPU interface 2/0/0 for configuration.
2. Configure the interface as an ATM ARP client with end-system identifier 0041.0b0a.1081.40.
3. Configure the interface IP address as 123.233.45.1 with a subnet mask of 255.255.255.0.
4. Specify the ARP server NSAP address as 47.0091.8100.0000.1111.1111.1111.2222.2222.2222.00
Cisco's implementation of the ATM ARP server supports a single, nonredundant server per LIS and one ATM ARP server per subinterface. Thus, a single LightStream 1010 ATM switch can support multiple ARP servers by using multiple interfaces.
To configure the ATM ARP server, complete the following tasks, beginning in global configuration mode
| Step | Command | Task |
|---|---|---|
| 1 | interface atm 2/0/0[.sub_inter #] | Select the interface to be configured. |
| 2 | atm nsap-address nsap-address | Specify the NSAP ATM address of the interface. |
| 3 | atm arp-server self | |
| 4 | ip address address mask | Specify the IP address of the interface. |
| 5 | atm arp-server time-out minutes1 | Configure the ATM ARP server optional idle timer. |
You can designate the current LightStream 1010 ATM switch as the ATM ARP server by adding the keyword self.
The idle timer interval is the number of minutes a destination entry listed in the ATM ARP server's ARP table can be idle before the server takes any action to timeout the entry.
The following example configures the CPU interface 2/0/0 as an ARP server (shown in Figure 13-1):
ARP_Server(config)# interface atm 2/0/0 ARP_Server(config-if)# atm esi-address 0041.0b0a.1081.40 ARP_Server(config-if)# atm arp-server self ARP_Server(config-if)# ip address 123.233.45.2 255.255.255.0
In order, these commands:
1. Identify CPU interface 2/0/0 for configuration.
2. Configure the interface as an ATM ARP server with ESI 0041.0b0a.1081.40.
3. Configure the IP address as 123.233.45.2 and subnet mask 255.255.255.0.
To show the IP over ATM interface configuration, use the following commands:
| Command | Task |
|---|---|
Show the ATM interface ARP configuration. | |
Show the ATM map list configuration. |
In the following example, the show atm arp command displays the configuration of the switch interface 2/0/0:
Switch# show atm arp
Note that a '*' next to an IP address indicates an active call
IP Address TTL ATM Address
ATM2/0/0:
* 10.0.0.5 19:21 4700918100567000000000112200410b0a108140
The following example displays the map-list configuration of the switch static map and IP-over-ATM interfaces:
Switch# show atm map
Map list ATM2/0/0_ATM_ARP : DYNAMIC
arp maps to NSAP 36.0091810000000003D5607900.0003D5607900.00
, connection up, VPI=0 VCI=73, ATM2/0/0
ip 5.1.1.98 maps to NSAP 36.0091810000000003D5607900.0003D5607900.00
, broadcast, connection up, VPI=0 VCI=77, ATM2/0/0
Map list ip : PERMANENT
ip 5.1.1.99 maps to VPI=0 VCI=200
This section describes how you configure classical IP over ATM in a PVC environment. The ATM Inverse ARP mechanism is applicable to networks that use PVCs, where connections are established but the network addresses of the remote ends are not known. A server function is not used in this mode of operation.
In a PVC environment, configure the ATM Inverse ARP mechanism by performing the following tasks:
| Step | Command | Task |
|---|---|---|
| 1 | interface atm 2/0/0 | Select the interface to be configured. |
| 2 | ip address address mask | Specify the IP address of the interface. |
| 3 | atm pvc vpi vci encap aal5snap [inarp minutes] |
Repeat these tasks for each PVC you want to create.
The inarp minutes interval specifies how often Inverse ARP datagrams are sent on this virtual circuit. The default value is 15 minutes.
The following example shows how to configure an IP-over-ATM interface in a PVC environment:
Switch(config)# interface atm 2/0/0 Switch(config)# ip address 11.11.11.11 Switch(config-if)# atm pvc 0 100 encap aal5snap inarp 10 interface atm 0/0/0 50 100
In order, these commands:
1. Identify CPU interface 2/0/0 for configuration.
2. Configure the IP address on the interface as 11.11.11.11.
3. Create an ATM PVC with AAL5SNAP encapsulation, inverse ARP set to ten minutes, on ATM interface 0/0/0 VPI = 50 VCI = 100.
To show the IP-over-ATM interface configuration, use the following command:
| Command | Task |
|---|---|
Show the ATM interface ARP configuration. |
The following example displays the map-list configuration of the switch static map and IP over ATM interfaces:
Switch# show atm map
Map list yyy : PERMANENT
ip 1.1.1.2 maps to VPI=0 VCI=200
Map list zzz : PERMANENT
Map list a : PERMANENT
Map list 1 : PERMANENT
Map list ATM2/0/0_ATM_ARP : DYNAMIC
arp maps to NSAP 47.009181005670000000001122.00410B0A1081.40
, connection up, VPI=0 VCI=85, ATM2/0/0
ip 10.0.0.5 maps to NSAP 47.009181005670000000001122.00410B0A1081.40
, broadcast, ATM2/0/0
The ATM interface supports a static mapping scheme that identifies the ATM address of remote hosts or switches. This IP address is specified as a PVC or as an NSAP address for SVC operation. Configuration for both PVC and SVC map lists are described in the following sections:
This section describes how to map a PVC to an address, which is a required task if you are configuring a PVC.
You enter mapping commands as groups. You first create a map list and then associate it with an interface. Begin with the following tasks:
| Step | Command | Task |
|---|---|---|
| 1 | ip host-routing | Enable IP host based routing. |
| 2 | interface atm card/subcard/port[.sub_inter #] | Specify an ATM interface and enter interface configuration mode. |
| 3 | ip A.B.C.D mask | Enter the IP address and subnet mask associated with this interface. |
| 4 | map-group name | Enter the map group name associated with this PVC. |
| 5 | atm pvc vpi vci [encap aal5lane aal5mux aal5snap] [upc upc] [pd pd] [rx-cttr index] [tx-cttr index] interface atm card/subcard/port[.sub_inter #] vpi vci [upc upc] | Configure the PVC. |
| 6 | exit | Exit interface configuration mode. |
| 7 | ip route A.B.C.D mask [A.B.C.D | atm | ethernet | null] | Configure an IP route to the router. |
| 8 | map-list name | Create a map list by naming it, and enter map-list configuration mode. |
| 9 | ip A.B.C.D atm-nsap address | atm-vc vci {aal5mux encapsulation | broadcast pseudo-broadcast | class class-name} | Associate a protocol and address to a specific virtual circuit. |
You can create multiple map lists, but only one map list can be associated with an interface. Different map lists can be associated with different interfaces.
Figure 13-2 illustrates a connection configured with a PVC map list.

The following shows the commands used to configure the connection in Figure 13-2.
Switch(config)# ip host-routing Switch(config)# interface atm 2/0/0 Switch(config-if)# ip address 1.1.1.1 255.0.0.0 Switch(config-if)# map-group yyy Switch(config-if)# atm pvc 0 200 encap aal5snap interface atm 3/0/0 100 300 Switch(config-if)# exit Switch(config)# ip route 1.1.1.1 255.0.0.0 1.1.1.2 Switch(config)# map-list yyy Switch(config-map-list)# ip 1.1.1.2 atm-vc 200 Switch(config-map-list)# end
In order, these commands:
1. Enable IP host-based routing.
2. Change to interface configuration mode on ATM CPU interface 2/0/0.
3. Configure the interface with map group name "yyy."
4. Configure an internal cross-connect PVC from the CPU interface to ATM interface 3/0/0 VPI 100 and VCI 300.
5. Exit interface configuration mode.
6. Configure a static IP route between the switch and the router.
7. Change to map list configuration mode and create a map group with the name "yyy."
8. Associate the map list to the IP network connection 1.1.1.2 and ATM VC 200 configured on ATM interface 3/0/0.
To show the map-list interface configuration, use the following command:
| Command | Task |
|---|---|
Show the ATM interface map-list configuration. |
The following example displays the map-list configuration of the LightStream 1010 ATM switch at interface 2/0/0:
Switch# show atm map Map list yyy : PERMANENT ip 1.1.1.2 maps to VPI=0 VCI=200
This section describes how to map an SVC to an NSAP address. This is a required task if you are configuring an SVC.
You enter mapping commands as groups. You first create a map list and then associate it with an interface. Perform the following tasks:
| Step | Command | Task |
|---|---|---|
| 2 | ip host-routing | Enable IP host-based routing. |
| 3 | interface atm card/subcard/port [.sub_inter #] | Specify an ATM interface and enter interface configuration mode. |
| 4 | ip A.B.C.D mask | Enter the IP address and subnet mask associated with this interface. |
| 5 | atm nsap-address 20-octet NSAP address | Configure the interface NSAP address. |
| 6 | map-group name | Enter the map-group name associated with this PVC. |
| 7 | exit | Exit interface configuration mode. |
| 8 | map-list name | Create a map list by naming it, and enter map-list configuration mode. |
| 9 | ip A.B.C.D atm-nsap address | atm-vc vci {aal5mux encapsulation | broadcast pseudo-broadcast | class class-name} | Associate a protocol and address to a specific virtual circuit. |
You can create multiple map lists, but only one map list can be associated with an interface. Different map lists can be associated with different interfaces.
Figure 13-3 illustrates an SVC connection configured with a map list.

The following example shows the commands used to configure the connection in Figure 13-3:
Switch(config)# ip host-routing Switch(config)# interface atm 2/0/0 Switch(config-if)# ip address 1.1.1.1 255.0.0.0 Switch(config-if)# map-group zzz Switch(config-if)# atm nsap-address 47.0091.1111.1111.1111.1111.1111.1111.1111.1111.00 Switch(config-if)# exit Switch(config)# ip route 1.1.1.1 255.0.0.0 1.1.1.2 Switch(config)# map-list zzz Switch(config-map-list)# ip 1.1.1.2 atm-nsap ac.1533.2222.2222.2222.2222.2222.2222.2222.2222.00 Switch(config-map-list)# end
In order, these commands:
1. Enable IP host-based routing.
2. Change to interface configuration mode on ATM CPU interface 2/0/0.
3. Configure the interface with map group name "zzz."
4. Configure the interface with IP address 1.1.1.1 and a subnet mask.
5. Configure the interface with NSAP address 47.0091.1111.1111.1111.1111.1111.1111.1111.1111.00.
6. Exit interface configuration mode.
7. Configure a static IP route between interface 1.1.1.1 and 1.1.1.2.
8. Switch to map-list configuration mode to map group name "zzz."
9. Associate the IP interface 1.1.1.2 with NSAP address ac.1533.2222.2222.2222.2222.2222.2222.2222.2222.2222.00.
To show the map-list interface configuration, use the following command:
| Command | Task |
|---|---|
Show the ATM interface map-list configuration. |
The following example displays the map-list configuration of the LightStream 1010 ATM switch at interface 2/0/0:
Switch# show atm map Map list yyy : PERMANENT ip 1.1.1.1 maps to VPI=0 VCI=200 ip 1.1.1.2 maps to VPI=0 VCI=200 Map list zzz : PERMANENT
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