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This chapter describes how to configure IP over ATM on the 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 ATM switch to allow a classical IP-over-ATM connection to the ATM switch's processor.
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 12-1 describes the steps needed to set up a classical IP-over-ATM connection between 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 atm0 | Select the interface to be configured. |
| 2 | atm nsap-address nsap-address | Specify the NSAP ATM address of the interface. |
| 3 | ip address ip-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 ATM switch to the processor interface. See the following note. |
| 1First 19 bytes of the NSAP address. |
The following example shows how to configure the processor interface atm0 of client A, in Figure 12-1, using the NSAP address:
Client A(config)# interface atm0 Client A(config-if)# atm nsap-address 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)# atm arp-server nsap 47.0091.8100.0000.1111.1111.1111.2222.2222.2222.00 Client A(config-if)# exit Client A(config)# atm route 47.0091.8100.0000.1111.1111.1111.1111.1111.1111 atm0 internal
The following example shows how to configure processor interface atm0 of client A (Figure 12-1), using the ESI:
Client A(config)# interface atm0 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)# atm arp-server nsap 47.0091.8100.0000.1111.1111.1111.2222.2222.2222.00 Client A(config-if)# exit
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 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 atm0[.subinterface#] | Select the interface to be configured. |
| 2 | atm nsap-address nsap-address | Specify the NSAP ATM address of the interface. |
| 4 | ip address ip-address mask | Specify the IP address of the interface. |
| 5 | atm arp-server time-out minutes1 | Configure the ATM ARP server optional idle timer. |
| 6 | Configure a static route through the ATM switch to the processor interface. See the following note. |
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 processor interface atm0 as an ARP server (shown in Figure 12-1):
ARP_Server(config)# interface atm0 ARP_Server(config-if)# atm esi-address 0041.0b0a.1081.00 ARP_Server(config-if)# atm arp-server self ARP_Server(config-if)# ip address 123.233.45.2 255.255.255.0
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-server command displays the configuration of the interface atm0:
Switch# show atm arp-server
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 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 s 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 atm0 | Select the interface to be configured. |
| 2 | ip address ip-address mask | Specify the IP address of the interface. |
| 3 | atm pvc vpi1 vci encap aal5snap [inarp minutes] |
| 1The VPI value on interface atm0 must always be 0. |
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 on interface atm0, using a PVC with AAL5SNAP encapsulation, inverse ARP set to ten minutes, VPI = 0, and VCI = 100:
Switch(config)# interface atm0 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
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 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 ATM 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. Perform the following tasks, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | Enable IP host based routing. | |
| 2 | interface atm card/subcard/port[.subinterface] | Specify an ATM interface and enter interface configuration mode. |
| 3 | ip ip-address 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-a vci-a [encap aal-encap] [upc upc] [pd pd] [rx-cttr index] [tx-cttr index] interface atm card/subcard/port[.vpt#] vpi-b vci-b [upc upc] | Configure the PVC. |
| 6 | exit | Exit interface configuration mode. |
| 7 | ip route ip-address mask | 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 ip-address 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 12-2 illustrates a connection configured with a PVC map list.
The following shows the commands used to configure the connection in Figure 12-2.
Switch(config)# ip host-routing Switch(config)# interface atm0 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
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 at interface atm0:
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, beginning in global configuration mode:
| Step | Command | Task |
|---|---|---|
| 1 | Enable IP host-based routing. | |
| 2 | interface atm card/subcard/port [.subinterface] | Specify an ATM interface and enter interface configuration mode. |
| 3 | ip ip-address mask | Enter the IP address and subnet mask associated with this interface. |
| 4 | atm nsap-address nsap-address | Configure the interface NSAP address. |
| 5 | map-group name | Enter the map-group name associated with this PVC. |
| 6 | exit | Exit interface configuration mode. |
| 7 | map-list name | Create a map list by naming it, and enter map-list configuration mode. |
| 8 | ip ip-address 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 12-3 illustrates an SVC connection configured with a map list.
The following example shows the commands used to configure the connection in Figure 12-3:
Switch(config)# ip host-routing Switch(config)# interface atm0 Switch(config-if)# ip address 1.1.1.1 255.0.0.0 Switch(config-if)# atm nsap-address 47.0091.1111.1111.1111.1111.1111.1111.1111.1111.00 Switch(config-if)# map-group zzz Switch(config-if)# exit Switch(config)# map-list zzz Switch(config-map-list)# ip 1.1.1.2 atm-nsap 39.1533.2222.2222.2222.2222.2222.2222.2222.2222.00
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 at interface atm0:
Switch# show atm map Map list zzz : PERMANENT ip 1.1.1.2 maps to NSAP AC.153322222222222222222222.222222222222.00
Posted: Fri Apr 9 10:03:31 PDT 1999
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