# Creating a Basic Configuration

To configure ATM, perform the following tasks. (Figure 3 shows the relationship of Steps 1 through 3.)

1. Configure an ATM physical interface.
   host1(config)#interface atm 0/1
2. Configure an ATM 1483 subinterface.
   host1(config-if)#interface atm 0/1.20
3. Configure a PVC by specifying the VCD, the VPI, the VCI, and the encapsulation type.
   host1(config-subif)#atm pvc 10 15 22 aal5snap
4. Assign an IP address and subnet mask to the PVC.
   host1(config-subif)#ip address 192.32.10.20 255.255.255.0
5. (Optional) Verify your configuration using the appropriate show commands.
   host1#show atm interface atm 0/1 host1#show atm vc atm 0/1 10 host1#show atm subinterface atm 0/1.20

   Figure 3: Configuring an ATM Interface, Subinterface, and PVC

atm pvc

- Use to configure a PVC on an ATM interface.
- Specify one of the following encapsulation types:
  - aal5snap—Specifies an LLC encapsulated circuit; LLC/SNAP header precedes the protocol datagram.
  - aal5mux ip—Specifies a VC-based multiplexed circuit. This option is used for IP only.
  - aal5autoconfig—Enables autodetection of the 1483 encapsulation (LLC/SNAP or VC multiplexed) for dynamic interfaces. See Configuring Dynamic Interfaces, for more explanation.
  - ilmi—Defines the PVC for ILMI keepalive messages. You can set this option only on major interfaces. After the PVC is set up for ILMI, use atm ilmi-keepalive to cause the router to generate ILMI keepalive messages on the interface.
- You can optionally set the peak, average, and burst sizes. To use VBR-RT or VBR-NRT as the service type, you must specify each of these options.
- The default service type is UBR. To set a different service type, specify one of the following keywords:
  - rt—Selects VBR-RT as the service type. You can select rt only if you set the peak, average, and burst parameters.
  - cbr—Selects CBR as the service type. You must set the CBR rate in Kbps.
- To enable VC integrity and generation of OAM F5 loopback cells on this circuit, use the oam keyword.
- Example
  host1(config-if)#atm pvc 6 0 11 aal5snap cbr 10000
- Use the no version to remove the specified PVC.
- See atm pvc.

interface atm

- Use to configure an ATM interface or subinterface type.
- To specify an ATM interface for ERX7xx models, ERX14xx models, and ERX310 router, use the slot/port.[subinterface ] format.
  - slot—Number of the chassis slot
  - port—Port number on the I/O module; on the OC3-2 GE APS I/O module, you can specify ATM interfaces only in ports 0 and 1; port 2 is reserved for a Gigabit Ethernet interface
  - subinterface—Number of the subinterface in the range 1–2147483647
- To specify an ATM interface for the E120 or E320 router, use the slot/adapter/port[.subinterface ] format.
  - slot—Number of the chassis slot
  - adapter—Identifier for the IOA within the E320 chassis, either 0 or 1, where:
    - 0 indicates that the IOA is installed in the right IOA bay (E120 router) or the upper IOA bay (E320 router)
    - 1 indicates that the IOA is installed in the left IOA bay (E120 router) or the lower IOA bay (E320 router).
  - port—Port number on the IOA
  - subinterface—Number of the subinterface in the range 1–2147483647
- Specify the type of interface or subinterface: point-to-point or multipoint. Point-to-point is the default.
- Examples
  host1(config-if)#interface atm 0/1.20 host1(config-if)#interface atm 0/0/4.20
- Use the no version to remove the subinterface or the logical interface.
- See interface atm.