Preparing for IP Communications over an ATM Interface

Configuration Overview

Configuring the Switch

Configuring the Router

Preparing for IP Communications over an ATM Interface

This chapter describes how to prepare your network to support IP-based network management over an ATM interface. This feature allows you manage MGX 8850 switches from remote locations using ATM connections instead of additional LAN or dial-up connections.

This chapter presents an overview of IP connectivity over the ATM interface and describes how to configure switches and routers to support this feature.

Configuration Overview

Figure B-1 shows an example topology that supports IP connectivity over ATM.

Figure B-1: IP Connectivity over ATM

The workstation in Figure B-1 uses a LAN to connect to a router that supports both LAN and ATM interfaces. An IP address is assigned to an ATM interface in each Cisco MGX 8850. To manage an MGX 8850, the workstation operator configures a network management program to communicate with the IP address assigned to the ATM interface. Network managers can use the following tools to manage the switch:

Command Line Interface (CLI) using a Telnet session
Cisco WAN Manager (CWM)
Third-party Simple Network Management Protocol (SNMP) manager

To support the ATM SVCs over which the IP traffic travels, both the router and switch are configured to map the respective IP addresses to ATM End Station Addresses (AESAs). When a management session is initiated, the IP workstation directs all communications to the IP address assigned to the ATM interface on the switch. The router encapsulates this IP traffic in ATM cells and forwards it over SVCs to the switch. The destination switch retrieves the IP messages from the ATM cells and forwards them to the internal IP management tools. Replies to the workstation follow the same path in reverse.

This feature provides maximum flexibility for switch management. Any workstation with a connection to a properly-configured ATM router can manage any switch in the network. Furthermore, additional routers connected to other switches can be configured to support this feature, enabling switch configuration from multiple locations throughout an ATM network.

Configuring the Switch

To support IP connectivity over the ATM interface, you need to do the following:

Assign an IP address to the ATM interface
Assign an AESA to the ATM interface
Define an AESA for every adjacent router that supports IP communications to the ATM interface
Configure ATM communications between the switch and the router

To configure the switch to support IP connectivity to the ATM interface, use the following procedure.

Step 1 Establish a CLI management session with the switch as described in "Establishing and Ending a CLI Management Session," which is in "Configuring General Switch Features."

Step 2 Verify that the IP address for the ATM interface is not already configured by entering the following command:

mgx8850a.7.PXM.a> dspipif atm0

Note If you omit the atm0 option, the switch displays the configuration for all switch IP interfaces: the ATM interface (atm0), the PXM45 LAN port interface (lnPci0), and the PXM45 maintenance port interface (sl0).

In the IP Interface Configuration Table, look for an Internet address entry under the atm entry. If an IP address is configured, you can use that address. However, if the address has not been entered or is incompatible with your network, you must configure a valid IP address as described in the next step.

Step 3 To set the switch IP address for the ATM interface, enter the ipifconfig command using the following format:

mgx8850a.7.PXM.a> ipifconfig atm0 <IP_Addr> <netmask Mask>

Replace IP_Addr with the IP address you want this port to use, and replace Mask with the network mask used on this network.

Tips Cisco recommends that you use the same subnet for all IP addresses defined on all MGX 8850s. This simplifies router configuration.

Note There are other options for the ipifconfig command, and you can set one or more options simultaneously. Any options you don't define in a command remain unchanged. For more information on this command, refer to Cisco MGX 8850 Command Reference, Release 2.0.

Step 4 To verify the IP address you configured, enter the following command:

mgx8850a.7.PXM.a> dspipif atm0

Step 5 Make a note of the IP address defined for the atm0 interface. This is the IP address switch administrators must use to manage the switch.

Step 6 Configure the switch AESA for IP connectivity by entering the following command:

mgx8850a.7.PXM.a> svcifconfig atm0 local <ATM_Addr>

Replace ATM_Addr with the AESA for the interface. This address must conform to the address plan for the switch.

Step 7 Define the AESA for the ATM router by entering the following command:

mgx8850a.7.PXM.a> svcifconfig atm0 router <ATM_Addr>

Replace ATM_Addr with the AESA for the interface. This address must conform to the address plan for the switch.

Step 8 To verify the ATM addresses you configured, enter the following command:

mgx8850a.7.PXM.a> dspsvcif

Step 9 If you have not already done so, configure the PNNI controller as described in "Configuring the PNNI Controller," which is in "Configuring General Switch Features."

Step 10 Configure the ATM line to the ATM router as described in "Configuring ATM Lines and Trunks."

The line configuration should specify a UNI port, SCT 6, and a partition that supports at least 20 connections.

Step 11 To verify connectivity to directly-attached ATM routers, enter the dsppnsysaddr command.

The ATM addresses of directly-attached ATM routers should appear in the list the switch displays. To display an ATM address for a remote router, you need to establish a CLI session on the remote switch and enter the dsppnsysaddr command.

Step 12 To check the status of ports leading to directly-attached ATM routers, enter the dsppnports command.

The following example shows commands that you can use to configure an MGX 8850 for IP communications over ATM.

Example B-1: Switch Commands for IP Communications over ATM

mgx8850a.7.PXM.a> ipifconfig atm0 A.B.E.F    # Replace A.B.E.F with IP Address
mgmgx8850a.7.PXM.a> svcifconfig atm0 local 47.0091.8100.0000.0010.7b65.f258.0010.7b65.1111.01
mgx8850a.7.PXM.a> svcifconfig atm0 router 47.0091.8100.0000.0010.7b65.f258.0010.7b65.ffff.f1
mgx8850a.7.PXM.a> addcontroller 2 i 2 7 #if controller does not already exist
mgx8850a.10.AXSM.a > cnfcdsct 6
mgx8850a.10.AXSM.a > upln 1.1
mgx8850a.10.AXSM.a > addport 1 1.1 96000 96000 6 1
mgx8850a.10.AXSM.a > addpart 1 1 2 500000 500000 500000 500000 1 20 32 52 1 20
mgx8850a.10.AXSM.a > upport 1
mgx8850a.7.PXM.a> dsppnsysaddr
 
(example output)
47.0091.8100.0000.0010.7b65.f258.0010.7b65.ffff/152
Type:      uni     Port id:   17111041
 
mgx8850a.7.PXM.a> dsppnports
 
(example output)
Per-port status summary
 
PortId         IF status         Admin status       ILMI state       Total Activeconns
 
10:1.1:1        up                up                 Undefined        3

Configuring the Router

To support IP over ATM communications on the ATM router, you need to configure the following interfaces:

ATM interface to switch
Interface to the LAN that hosts the management workstation

To configure the ATM interface to the switch, you need to do the following:

Create an ATM interface
Assign an IP address to the ATM interface
Assign an AESA to the ATM interface
Configure the ATM interface to be the ATMARP server for the switch

To configure the IP interface to the LAN, you need to do the following:

If the router's IP address for the ATM interface is on the same subnet as the IP address on the switch ATM interface, no additional configuration is required for the router's IP LAN interface.
If the router's IP address for the ATM interface is not on the same subnet as the IP address on the switch ATM interface, you must manually configure on IP host-route for each MGX 8850 to which the interface will connect.
Configure a routing protocol to broadcast the switch IP addresses to the LAN or create default routes to the switch on the management workstation.

The procedure you use to configure the ATM router will depend on the router you are using. The following example lists commands you can use on a Cisco router to support IP over ATM communications with the MGX 8850.

Example B-2: Router Configuration Commands for IP Communications over ATM

config term
ip routing
ip route 0.0.0.0 0.0.0.0 W.X.Y.Z 1 (set default route)
interface atm 0
ip address A.B.C.D G.H.I.J   # G.H.I.J = netmask
atm nsap-address 47.0091.8100.0000.0010.7b65.f258.0010.7b65.ffff.f1
atm uni-version 3.1
atm pvc 1 0 5 qsaal
atm arp-server self
no shut
^Z
 
write memory

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