Configuring Service Point on the Host and Routers

This appendix provides detailed information about how to configure your VTAM and router definitions to support SNA service point. Two items must be considered when establishing a service point connection from a router to the host:

Connecting to the host. This can be done using a MAC address from either an IBM 3745 front-end processor (FEP) or from a CSNA connection on a CIP card. The example provided in this appendix uses a CSNA on the CIP.
Configuring and enabling routers as switched PUs and with service point definitions.

This appendix contains the following sections:

Configuration Notes for VTAM Definitions

Figure B-1 provides a diagram of a sample VTAM configuration and its corresponding router configuration. If you are using a CIP CSNA connection to the host, then external communication adapter (XCA) definitions are needed (file XCANSP). Use SWNET definitions in VTAM (file CWBTRN001) to define the routers as switched PUs on the host.

Figure B-1: Sample VTAM and Router Configurations for Service Point

Figure B-2 shows the sample network architecture corresponding to the configurations defined in Figure B-1. Figure B-2 shows eight switched PU (SNA service point) routers (IBURMT01-8) that are using the DLSw protocol as the method for establishing an SNA connection to the host.

Figure B-2: Sample Network Configuration

Configuring an XCA Definition

If you are using a CIP CSNA connection to the host, then an external communication adapter (XCA) definition is needed (file XCANSP). The XCA definition in the example in Figure B-1 uses the following arguments:

Command Description

ADAPNO=8

Adapter number that contains the MAC address that is defined on the CIP router.

CUADDR=4C8A

Device or subchannel address that is obtained from the host MVS systems or VTAM programmer.

SAPADDR=04

SAP address that is referred to later as the RSAP address in the switched PU router configurations (you usually use a host SAP address of 04).

Command	Description
ADAPNO=8	Adapter number that contains the MAC address that is defined on the CIP router.
CUADDR=4C8A	Device or subchannel address that is obtained from the host MVS systems or VTAM programmer.
SAPADDR=04	SAP address that is referred to later as the RSAP address in the switched PU router configurations (you usually use a host SAP address of 04).

Configuring an SWNET Definition

Use SWNET definitions (file CWBTRN001) to define the routers as switched PUs on the host. Unlike PUs that are connected by leased line, where you always know what is at the other end of the line, switched PUs can connect to numerous locations of your network. Each router to which you want to establish a service point connection needs to be defined as PU type 2 in a SWNET definition file.

The SWNET definition in Figure B-1 uses the following arguments:

Command Description

IBURMT01

PU type 2 service point name of the router with which you want to establish a switched PU connection.

IDBLK=05D, IDNUM=88801

Both arguments make up the XID number that is used in the switched PU router configuration. The XID number must be unique across your network and it identifies the PU no matter where it connects to your network.

Command	Description
IBURMT01	PU type 2 service point name of the router with which you want to establish a switched PU connection.
IDBLK=05D, IDNUM=88801	Both arguments make up the XID number that is used in the switched PU router configuration. The XID number must be unique across your network and it identifies the PU no matter where it connects to your network.

Configuration Notes for Router Definitions

Figure B-1 provides a diagram of a sample router configuration and its corresponding VTAM configuration. The following CIP CSNA definitions on the Neuse router provide access to the host:

Command Description

interface channel 4/1

Physical location of the CIP card installed on the router, slot 4 port 1.

csna E010 8A

ESCON director port number (E0) to which the host is connected (the 1 is the LPAR number, the 0 is the control unit logical address, and the 8A is the device or subchannel address).

interface channel 4/2

CIP card port two, where all virtual definitions are configured.

lan TokenRing 0 adapter 8

Token Ring card (lan TokenRing 0) is virtually defined and has a virtual device (adapter 8), which has a virtually defined MAC address (4000.8888.000) on the CIP card.

Command	Description
interface channel 4/1	Physical location of the CIP card installed on the router, slot 4 port 1.
csna E010 8A	ESCON director port number (E0) to which the host is connected (the 1 is the LPAR number, the 0 is the control unit logical address, and the 8A is the device or subchannel address).
interface channel 4/2	CIP card port two, where all virtual definitions are configured.
lan TokenRing 0 adapter 8	Token Ring card (lan TokenRing 0) is virtually defined and has a virtual device (adapter 8), which has a virtually defined MAC address (4000.8888.000) on the CIP card.

Using VDLC to Obtain a Service Point Connection

This section provides information on using virtual data link control (VDLC) as a method of obtaining a service point connection to the host. To configure SNA Service Point to use VDLC, create an SNA VDLC interface.

The SNA VDLC interface uses the concept of a virtual Token Ring device residing on a virtual Token Ring to represent the Cisco IOS software to upstream hosts and downstream PUs across a network.
The upstream host and downstream PU expect their peer to be on a Token Ring. Therefore, you must assign a virtual Token Ring address (the SNA VDLC virtual MAC address) to the SNA VDLC interface. The SNA virtual MAC address must be unique across the network.
In addition to assigning the SNA VDLC virtual MAC address, you must also identify the source-route bridging virtual ring number with which the SNA virtual MAC address is associated.
The source-route bridging virtual ring number is set using the source-bridge ring-group command. The combination of the SNA virtual MAC address and the source-route bridging virtual ring number identifies the SNA VDLC interface to the rest of the DLSw+ network.

Figure B-1 shows an example of the following commands used in the IBURMT01 router configuration:

Command Description

source-bridge ring-group 100

Virtually defined source-bridge ring-group number that ties the SNA VDLC interface in with the DLSw network of routers IBURMT01-08.

dlsw local-peer peer-id 171.68.104.36 group 1

DLSw statement for the IBURTM01 router.

sna vdlc 100 0888.8888.8801

Virtual MAC address on source-bridge ring-group 100.

sna vdlc enable-host lsap 12

Command to enable the local SAP. Ready to accept incoming connection attempts from the remote host via VDLC.

sna host IBURMT01 xid-snd 05d88801 rmac 4000.8888.0000 rsap 4 lsap 12 focalpoint

The sna host command uses the following arguments:

IBURMT01 is the PU (service point) name of this router that was specified in the VTAM example for the SWNET major node definition file CWBTRN01.

xid-snd 05d88801 is the XID that will be sent to the host during connection establishment (this is the IDBLK and IDNUM numbers in the VTAM example for the SWNET major node definition file CWBTRN01).

rmac 4000.8888.0000 is the MAC address of the remote host PU. This is the virtual MAC address defined on the CIP router named Neuse in Figure B-2.

rsap 4 is the SAP address of the remote host PU. This is defined in the VTAM example for the XCA major node (file XCANSP).

lsap 12 specifies the local SAP address used by the SNA Service Point to establish a connection with the remote host.

focalpoint specifies that the host link will be used for focal point support.

sna vdlc start IBURMT01

Statement that initiates a connection from IBURMT01 to the host using VDLC.

snmp-server community public RO

Read-only access for the SNMP protocol to retrieve MIB objects.

snmp-server community private RW

Read-write access for the SNMP protocol to both retrieve and modify MIB objects.

Command	Description
source-bridge ring-group 100	Virtually defined source-bridge ring-group number that ties the SNA VDLC interface in with the DLSw network of routers IBURMT01-08.
dlsw local-peer peer-id 171.68.104.36 group 1	DLSw statement for the IBURTM01 router.
sna vdlc 100 0888.8888.8801	Virtual MAC address on source-bridge ring-group 100.
sna vdlc enable-host lsap 12	Command to enable the local SAP. Ready to accept incoming connection attempts from the remote host via VDLC.
sna host IBURMT01 xid-snd 05d88801 rmac 4000.8888.0000 rsap 4 lsap 12 focalpoint	The sna host command uses the following arguments: IBURMT01 is the PU (service point) name of this router that was specified in the VTAM example for the SWNET major node definition file CWBTRN01. xid-snd 05d88801 is the XID that will be sent to the host during connection establishment (this is the IDBLK and IDNUM numbers in the VTAM example for the SWNET major node definition file CWBTRN01). rmac 4000.8888.0000 is the MAC address of the remote host PU. This is the virtual MAC address defined on the CIP router named Neuse in Figure B-2. rsap 4 is the SAP address of the remote host PU. This is defined in the VTAM example for the XCA major node (file XCANSP). lsap 12 specifies the local SAP address used by the SNA Service Point to establish a connection with the remote host. focalpoint specifies that the host link will be used for focal point support.
sna vdlc start IBURMT01	Statement that initiates a connection from IBURMT01 to the host using VDLC.
snmp-server community public RO	Read-only access for the SNMP protocol to retrieve MIB objects.
snmp-server community private RW	Read-write access for the SNMP protocol to both retrieve and modify MIB objects.

Note Use different SAPs for the rsap and lsap addresses. Normally use rsap 04 for the host and lsap 12 for the router SAP, which are the default values. Use SNMP statements to configure an IPM source.

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