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Bridging and IBM Networking Configuration Guide
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About The Cisco IOS Software Documentation
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Bridging and IBM Networking Overview
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Configuring Transparent Bridging
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Configuring Source-Route Bridging
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Configuring Remote Source-Route Bridging
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Configuring Data-Link Switching Plus
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Configuring STUN and BSTUN
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Configuring LLC2 and SDLC Parameters
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Configuring IBM Network Media Translation
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Configuring DSPU and SNA Service Point Support
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Configuring SNA Frame Relay Access Support
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Configuring Advanced Peer-to-Peer Networking
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Configuring NCIA Client/Server Topologies
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Configuring IBM Channel Attach
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Table Of Contents
Configuring IBM Network Media Translation
Configure SDLLC with Direct Connection
Enable SDLLC Media Translation
Associate a Service Access Point (SAP) Value
Specify the Exchange Identification (XID) Value
Initiate Connection to Token Ring Host
Configure SDLLC with Remote Source-Route Bridging (RSRB)
Configure RSRB Using Direct Encapsulation
Configure RSRB over FST Connection
Configure RSRB over TCP Connection
Configure SDLLC with RSRB and Local Acknowledgment
Configure SDLLC with Ethernet and Translational Bridging
Customize SDLLC Media Translation
Set the Largest LLC2 I-Frame Size
Set the Largest SDLC I-Frame Size
Other Customizing Considerations
Monitor SDLLC Media Translation
QLLC Conversion Configuration Task List
Enable QLLC Conversion on a Serial Interface
Enable QLLC Conversion on the Appropriate Serial Interfaces
Define the XID Value Associated with an X.25 Device
Enable to Open a Connection to the Local Token Ring Device
Enable QLLC Local Acknowledgment for Remote Source-Route-Bridged Connections
Specify SAP Values Other Than the Default IBM SAP Values
Specify the Largest Packet That Can Be Sent or Received on the X.25 Interface
SDLLC with Direct Connection Example
SDLLC with Single Router Using RSRB Example
SDLLC with RSRB (Single 3x74) Example
SDLLC with RSRB (Multiple 3x74s) Example
SDLLC with RSRB and Local Acknowledgment Example
QLLC Conversion Configuration Examples
QLLC Conversion between a Single 37x5 and a Single 3x74 Example
QLLC Conversion between a Single 37x5 and Multiple 3x74s Example
QLLC Conversion between Multiple 37x5s and Multiple 3x74s Example
QLLC Conversion between a Single 37x5 and Multiple 3x74s across an Arbitrary WAN Example
NCP and VTAM Sysgen Parameters
Configuring IBM Network Media Translation
This chapter describes how to configure the Cisco IOS software for IBM network media translation with SDLLC or Qualified Logical Link Control (QLLC). For a complete description of the commands in this chapter, refer to the "IBM Network Media Translation Commands" chapter in the Bridging and IBM Networking Command Reference.
SDLLC Configuration Task List
To configure SDLLC, perform the tasks in the following sections:
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Configure SDLLC with Direct Connection
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Note
See the end of this chapter for "SDLLC Configuration Examples."
Configure SDLLC with Direct Connection
In the SDLLC configuration with direct connection, a 37x5 front-end processor (FEP) on a Token Ring and a 3x74 cluster controller connected to a serial line are each connected to an interface on the same router configured with SDLLC. In this configuration, the Logical Link Control, type 2 (LLC2) session extends from the 37x5 FEP across the Token Ring to the router. The SDLLC session extends from the router across the serial line to the 3x74 cluster controller. The Systems Network Architecture (SNA) session extends across the Token Ring and the serial line to provide an end-to-end connection. The router is configured with source-route bridging (SRB).
To configure SDLLC with direct connection, you must perform the tasks in the following sections:
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For an example of how to configure SDLLC with direct connection, see the "SDLLC with Direct Connection Example" later in this chapter.
Enable SDLLC Media Translation
The interfaces you will configure for SDLLC media translation are the serial interfaces that connect to the serial lines linking the remote Synchronous Data Link Control (SDLC) devices. To configure them, perform the following task in interface configuration mode:
Enable SDLLC media translation on a serial interface.
sdllc traddr xxxx.xxxx.xx00 lr bn tr
Associate a Service Access Point (SAP) Value
You can associate a SAP value by performing the following task in interface configuration mode:
Specify the Exchange Identification (XID) Value
The XID value you define in the Cisco IOS software must match that of the IDBLK and IDNUM system generation parameters defined in VTAM of the Token Ring host to which the SDLC device will be communicating. To define XID, perform the following task in interface configuration mode:
Specify the XID value appropriate for the SDLC station to match VTAM values.
sdllc xid address xxxxxxxx
Initiate Connection to Token Ring Host
The Token Ring host is always kept in a state ready to accept a connection from the remote serial device. The remote serial device is responsible for initiating connections. The advantage of this scheme is that the serial device can communicate with the Token Ring host whenever it chooses without requiring personnel to be on the host site.
The Cisco IOS software actually initiates the connection on behalf of the serial device. To initiate connections, both the media access control (MAC) address of the Token Ring host and the SDLC line address are required. You must configure the Cisco IOS software to define the Token Ring host as the partner of the serial device. To do so, perform the following task in interface configuration mode:
Configure SDLLC with Remote Source-Route Bridging (RSRB)
A router need not directly connect the two IBM end nodes: a 37x5 FEP on a Token Ring and a 3x74 cluster controller connected to a serial line can be connected to different routers. However, the router to which the 3x74 is connected must be configured with SDLLC. They communicate via RSRB using direct encapsulation, RSRB over an FST connection, or RSRB over a TCP connection. RSRB transports packets between Router A and Router B, while Router B performs all conversion between the LLC2 and SDLC protocols by means of the SDLLC software.
To configure the router for SDLLC with RSRB, you must perform all the tasks in the "Configure SDLLC with Direct Connection" section earlier in this chapter. In addition, you must perform one of the sets of tasks in the following sections:
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For more information about configuring RSRB, see the chapter "Configuring Source-Route Bridging" in this publication and "Source-Route Bridging Commands" in the Bridging and IBM Networking Command Reference.
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For an example of how to configure SDLLC with RSRB, see the section "SDLLC with RSRB (Multiple 3x74s) Example" later in this chapter.
Configure RSRB Using Direct Encapsulation
To configure SDLLC with RSRB using direct encapsulation, perform the following tasks in global configuration mode:
Define a ring group.
source-bridge ring-group ring-group [virtual-mac-address]1
Define a remote peer.
source-bridge remote-peer ring-group interface interface-name [mac-address]2
1 This command is documented in the "Source-Route Bridging Commands" chapter of the Bridging and IBM Networking Commands Reference.
2 This command is documented in the "Remote Source-Route Bridging Commands" chapter of the Bridging and IBM Networking Command Reference.
Configure RSRB over FST Connection
To configure SDLLC with RSRB over an FST connection, perform the following tasks in global configuration mode:
Define a ring group.
source-bridge ring-group ring-group [virtual-mac-address]1
For FST connection only, set up an FST peer name.
source-bridge fst-peername local-interface-address2
Define a remote peer.
source-bridge remote-peer ring-group fst ip-address2
1 This command is documented in the "Source-Route Bridging Commands" chapter of the Bridging and IBM Networking Commands Reference.
2 These commands are documented in the "Remote Source-Route Bridging Commands" chapter of the Bridging and IBM Networking Command Reference.
Configure RSRB over TCP Connection
To configure SDLLC with RSRB over a TCP connection, perform the following tasks in global configuration mode:
Define a ring group.
source-bridge ring-group ring-group [virtual-mac-address]1
Define a remote peer.
source-bridge remote-peer ring-group tcp ip-address2
1 This command is documented in the "Source-Route Bridging Commands" chapter of the Bridging and IBM Networking Commands Reference.
2 This command is documented in the "Remote Source-Route Bridging Commands" chapter of the Bridging and IBM Networking Command Reference.
Configure SDLLC with RSRB and Local Acknowledgment
RSRB can be configured for only local acknowledgment with RSRB using IP encapsulation over a TCP connection. Configuring SDLLC local acknowledgment can reduce time-outs and keepalive traffic on the connection.
If LLC2 local acknowledgment is configured, it must be configured on the serial interface of the router on the 3x74 cluster controller side of the connection and on the Token Ring interface of the router on the 37x5 FEP side of the connection. Whether or not local acknowledgment is configured, the SNA session extends end-to-end and the SDLC session extends from the router configured with the serial interface to the 3x74 cluster controller. However, the LLC2 session extends from the 37x5 FEP to the router with the Token Ring interface configured. The LLC2 session is locally terminated at that router. A TCP session is then established across the WAN to a router on the 3x74 side of the connection.
To configure the Cisco IOS software for SDLLC with RSRB and local acknowledgment, you must perform all the tasks in the "Configure SDLLC with Direct Connection" section earlier in this chapter. In addition, you must perform the following tasks in global configuration mode:
Local acknowledgment is not supported when the LLC2 device is attached to an Ethernet rather than to a Token Ring.
For an example of how to configure SDLLC with RSRB and local acknowledgment, see the section "SDLLC with RSRB and Local Acknowledgment Example" later in this chapter.
For more information about configuring RSRB and local acknowledgment, see the chapter "Configuring Source-Route Bridging" in this manual and "Source-Route Bridging Commands" in the Bridging and IBM Networking Command Reference.
Configure SDLLC with Ethernet and Translational Bridging
SDLLC support over Ethernet combines translational bridging with Ethernet support of 37x5 FEP connections. shows SDLLC with Ethernet and translational bridging. The 3x75 FEP is attached to Router A through Ethernet. The same router is configured for translational bridging, which translates Ethernet packets into Token Ring packets and passes them across the WAN to Router B connected to the 3x74 cluster controller via a serial line. The LLC2 session terminates at Router B connected to the 3x74 cluster controller. In addition, Router B maintains an SDLC session from itself to the cluster controller.
Figure 102 SDLLC with Ethernet and Translational Bridging
Customize SDLLC Media Translation
To increase performance on connections involving SDLLC media translation, perform the tasks in the following sections:
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Refer to "Other Customizing Considerations" at the end of this section for additional information.
Set the Largest LLC2 I-Frame Size
Generally, the router and the LLC2 device with which it communicates should support the same maximum SDLC I-frame size. The larger this value, the better the line is used, thus increasing performance.
Faster screen updates to 3278-style terminals often result by configuring the Token Ring FEP to send as large an I-frame as possible and then allowing the Cisco IOS software to segment the frame into multiple SDLC I-frames.
After the Token Ring FEP has been configured to send the largest possible I-frame, it is best to configure the software to support the same maximum I-frame size. The default is 516 bytes. The maximum value the software can support is 8144 bytes.
To set the largest LLC2 I-frame size, perform the following task in interface configuration mode:
Specify the largest I-frame size that can be sent or received by the designated LLC2 primary station.
sdllc ring-largest-frame value
Set the Largest SDLC I-Frame Size
Generally, the router and the SDLC device with which it communicates should support the same maximum SDLC I-frame size. The larger this value, the better the line is utilized, thus increasing performance.
After the SDLC device has been configured to send the largest possible I-frame, you must configure the Cisco IOS software to support the same maximum I-frame size. The default is 265 bytes. The maximum value the software can support must be less than the value of the LLC2 largest frame value defined when setting the largest LLC2 I-frame size.
To set the largest SDLC I-frame size, perform the following task in interface configuration mode:
Set the largest I-frame size that can be sent or received by the designated SDLC station.
sdllc sdlc-largest-frame address value
Increase the SDLC Line Speed
You can increase the data transfer rate by increasing the SDLC line speed on the serial interface. If possible, increase the link speed of the 3x74 to 19.2 kbps on older units, or to 64 kbps on new units.
To increase the SDLC line speed, perform the following tasks in interface configuration mode:
Adjust the clock rate on the serial interface of the SCI and MCI cards to an acceptable bit rate.
clock rate bps1
1 This command is documented in the "Interface Commands" chapter of the Configuration Fundamentals Command Reference.
Other Customizing Considerations
In addition to adjusting the SDLLC parameters described in this section, you can improve performance on the connection by adjusting the LLC2 and SDLC parameters described in the chapter "Configuring LLC2 and SDLC Parameters."
For IBM host configuration consider changing the default MAXOUT (window size) value. Widely used installation guides for IBM equipment show a MAXOUT value of 1 in the VTAM-switched major node for the IBM 3174 PU. Changing this value to 7 improves the performance, because VTAM can send seven frames before requiring an acknowledgment.
Monitor SDLLC Media Translation
To monitor connections using SDLLC media translation, perform the following monitoring tasks in privileged EXEC mode:
Display information about SDLC and LLC2 connections involving interfaces on which SDLLC media translation has been enabled.
show interfaces
Display the current state of any connections using local acknowledgment for LLC2 and SDLLC connections.
show sdllc local-ack
Display information about LLC2 connections involving interfaces on which SDLLC media translation has been enabled.
show llc21
1 This command is documented in the "LLC2 and SDLC Commands" chapter of the Bridging and IBM Networking Command Reference.
In show llc2 output, look for the LLC2 connections that correspond to the MAC addresses you assigned to the SDLLC interfaces using the sdllc traddr command. For information about these commands, see the chapter "LLC2 and SDLC Commands" and "IBM Network Media Translation Commands" in the Bridging and IBM Networking Command Reference.
QLLC Conversion Configuration Task List
Perform the tasks in the following sections to configure QLLC conversion. The first task is required; all others are optional and depend on your specific needs.
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See the end of this chapter for QLLC configuration examples.
Enable QLLC Conversion on a Serial Interface
The interfaces you configure for QLLC conversion are the serial interfaces that connect to the X.25 network linking the remote devices with which you plan to communicate.
To enable QLLC conversion, you must perform the first of the following tasks. Perform the remaining tasks as appropriate.
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Enable QLLC Conversion on the Appropriate Serial Interfaces
You can enable QLLC conversion on a serial interface to support either a switched virtual circuit (SVC) or a permanent virtual circuit (PVC). The tasks you perform differ somewhat depending on the type of virtual circuit you plan to support on the interface. In either case, first verify that RSRB is enabled by performing the following task in privileged EXEC mode:
Ensure that RSRB is enabled on the interfaces.
show configuration1
1 This command is documented in the "Image and Configuration File Load Commands" chapter of the Configuration Fundamentals Command Reference.
In the sections for the appropriate serial interfaces of the show configuration display, look for one or more source-bridge remote-peer entries and a source-bridge rn entry. For more information about configuring a serial interface for RSRB, see the chapter "Configuring LLC2 and SDLC Parameters" in this manual.
To enable QLLC conversion to support an SVC, perform the following tasks in interface configuration mode:
To enable QLLC conversion to support a PVC, perform the following tasks in interface configuration mode:
Step 1
x25 pvc circuit qllc x121-address [x25-map-options]
Step 2
qllc srb virtual-mac-addr srn trn
In a Token Ring or RSRB environment the LAN-attached devices initiate a connection by sending a null XID packet upstream. If the Cisco IOS software forwards this null XID to an X.25-attached FEP, the FEP responds as if it were connecting to an PU2.1 device, and breaks the connection when the PU 2.0 next sends an XID Format 0 Type 2. To resolve this situation and to enable the connection, perform the following task in interface configuration mode:
Enable connection between a PU 2.0 on the LAN side and a FEP running NPSI on the X.25 side.
qllc npsi-poll virtual-mac-addr
The qllc npsi-poll command intercepts any null XID packet that the router receives on the LAN interface, and returns a null XID response to the downstream device. It continues to allow XID Format 3 and XID Format 0 packets through the X.25 device.
Define the XID Value Associated with an X.25 Device
The exchange identification (XID) serves as a password to ensure that only those devices that should communicate with the Token Ring host have that privilege. If the XID is defined in NCP on the host, you must enable the Cisco IOS software to reply (on behalf of the X.25 device) to the Token Ring host's requests for an XID reply. Although the XID value is used to reply to XID requests received on the LLC2 side of the connection, you apply this command on the serial interface defined for X.25. This XID value must match that of IDBLK and IDNUM defined in the NCP.
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To define the XID value associated with an X.25 device, perform the following task in interface configuration mode:
Specify the XID value appropriate for the X.25 device associated with the Token Ring interface.
qllc xid virtual-mac-addr xid
Enable to Open a Connection to the Local Token Ring Device
If you plan to use SVCs rather than PVCs, you must enable the Cisco IOS software to open a connection to the local Token Ring device on behalf of the remote X.25 device when an incoming call is received. When QLLC conversion is used over an SVC, the remote X.25 device typically initiates the X.25/QLLC session, and the software in turn initiates the LLC2 session.
To enable the software to open a connection to the local Token Ring device, perform the following task in interface configuration mode:
Enable the software to open a connection to the local Token Ring device.
qllc partner virtual-mac-addr mac-addr
Customize QLLC Conversion
To customize your configuration of QLLC conversion, you can perform one or more of the following tasks:
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These tasks are described in the following sections.
Enable QLLC Local Acknowledgment for Remote Source-Route-Bridged Connections
Enable local acknowledgment when the round-trip time through the TCP/IP network is as large or larger than the LLC2 timeout period.
To enable QLLC local acknowledgment for RSRB connections, perform the following global configuration task on the router connected to the X.25 interface and configure the remote peers for local acknowledgment:
Enable QLLC local acknowledgment for remote source-route-bridged connections.
source-bridge qllc-local-ack
If, for example, Router B with X.25 interface has the IP address ip1, and the remote peer (Router A) has the address ip2, and they use a virtual ring group vrg, then both routers use the following configuration commands:
source-bridge ring-group vrgsource-bridge remote-peer vrg tcp ip1 local-acksource-bridge remote-peer vrg tcp ip2The configuration for Router B is as follows:
source-bridge ring-group vrgsource-bridge remote-peer vrg tcp ip1source-bridge remote-peer vrg tcp ip2 local-ackThis will not affect Router A.
Specify SAP Values Other Than the Default IBM SAP Values
To use SAP values other than the default IBM SAP values, perform the following task in interface configuration mode:
Specify a SAP value other than the default IBM SAP value.
qllc sap virtual-mac-addr ssap dsap
Specify the Largest Packet That Can Be Sent or Received on the X.25 Interface
There are two ways for a packet to become segmented:
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If the QLLC software does not perform SNA segmentation, then the X.25 software must be capable of performing X.25 segmentation of the largest packet that it can receive from the LLC2 side. This packet can be several thousand bytes long, whereas the typical size for X.25 packets is 1024 bytes or less. (The default is 128, but that can be overridden with larger values.) The X.25 software, especially in the X.25 attached IBM end station, might not be able to reassemble a very large packet. In this situation, specifying the largest QLLC packet can be useful.
By default, the maximum SNA data unit size established for the virtual circuit is the maximum packet size that can be sent or received on the X.25 interface. If packets received on the LLC2 interface are larger than the largest value allowed on the X.25 connection, they can be segmented by the X.25 software before being sent on the X.25 interface. Moreover, there is no reassembly on receiving packets on the X.25 interface before sending them on the LLC2 interface. Thus, you might need to reconfigure the maximum packet size for the X.25 interface to match that for the LLC2 interface.
When the remote X.25 device has a limit on the maximum total length of recombined X.25 segments it will support, you must ensure the length is not exceeded. For example, a device whose maximum SNA packet size is limited to 265 bytes might not be able to handle a series of X.25 packets that it has to recombine to make a 4, 8, or 17 KB SNA packet, such as one often encounters in an LLC2 environment.
You cannot configure the X.25 interface with a larger packet size than the LLC2 interface.
To specify the largest packet that can be sent or received on the X.25 interface, perform the following task in interface configuration mode:
Specify the largest packet that can be sent or received on the X.25 interface.
qllc largest-packet virtual-mac-address max-size
Monitor QLLC Conversion
To monitor connections using QLLC conversion, perform the following tasks in privileged EXEC mode:
Display information about X.25 and LLC2 connections involving interfaces on which QLLC conversion has been enabled.
show interfaces serial number1
Display the current state of any connections using QLLC local acknowledgment.
show qllc
Display information about LLC2 connections involving interfaces on which QLLC conversion has been enabled.
show llc22
1 This command is documented in the "Interface Commands" chapter of the Configuration Fundamentals Command Reference.
2 This command is documented in the "LLC2 and SDLC Commands" chapter of the Bridging and IBM Networking Command Reference.
SDLLC Configuration Examples
The following sections provide SDLLC configuration examples:
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Refer to the "NCP and VTAM Sysgen Parameters" section for sample NCP definitions that the 37x5 FEP in these topologies could use and VTAM definitions that the IBM host in these topologies could use to reflect the routers in the communication path.
SDLLC with Direct Connection Example
shows a router configuration when the router directly connects the Token Ring and the serial line. The Cisco IOS software is configured with SRB.
Figure 103 SDLLC Communication between a 37x5 and a 3x74 Connected to the Same Router (Direct Connection)
A configuration file that enables direct connection follows:
source-bridge ring-group 100!interface tokenring 0source-bridge 111 1 100!interface serial 0encapsulation sdlc-primarysdlc address c1sdllc traddr 0110.2222.3300 222 2 100 sdllc partner 4000.0122.0001 c1sdllc xid c1 1720001SDLLC with Single Router Using RSRB Example
shows a software configuration in which the router directly connects the Token Ring and the serial line, but uses RSRB to create a virtual ring 100. This configuration has the following characteristics:
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ring 111—bridge 1—ring 100—bridge 1—ring 8
Figure 104 SDLLC with Single Router Using RSRB
The following sample configuration file is for SDLLC with a single router using RSRB:
source-bridge ring-group 100source-bridge remote-peer 100 tcp 131.108.1.1source-bridge remote-peer 100 tcp 131.108.2.2interface tokenring 0ip address 131.108.2.2 255.255.255.0source-bridge 111 1 100interface serial 0encapsulation sdlc-primarysdlc address c1sdllc traddr 0110.2222.3300 8 1 100 sdllc partner 1000.5a7d.8123 c1sdllc xid c1 17200c1SDLLC with RSRB (Single 3x74) Example
In , SDLLC with RSRB connects a FEP (37x5) and a single 3x74 cluster controller. The host wants to communicate with a single 3174 that its FEP sees on a Token Ring. However, the 3x74 seen by the FEP is in fact SDLC device C1 connected by means of a serial link through a remote router.
Figure 105 SDLLC with RSRB with a Single 3x74
The configuration files for the network shown in follow.
Configuration for Router A
source-bridge ring-group 100source-bridge remote-peer 100 tcp 131.108.1.1source-bridge remote-peer 100 tcp 131.108.2.2!interface tokenring 0ip address 131.108.1.1 255.255.255.0source-bridge 10 1 100!interface ethernet 0ip address 131.108.2.1 255.255.255.0Configuration for Router B
source-bridge ring-group 100source-bridge remote-peer 100 tcp 131.108.1.1source-bridge remote-peer 100 tcp 131.108.2.2!interface tokenring 0ip address 131.108.2.2 255.255.255.0source-bridge 1 1 100!interface serial 0encapsulation sdlc-primarysdlc address c1sdllc traddr 0110.2222.3300 8 1 100 sdllc partner 1000.5a7d.8123 c1sdllc xid c1 17200c1SDLLC with RSRB (Multiple 3x74s) Example
In the setup shown in , Router A needs no SDLLC configuration, Router B has the SDLLC configuration and supports multipoint on the SDLC link with a modem-sharing device, and Router C is also configured with SDLLC. For information about the NCP and VTAM system generation (sysgen) parameters that are used in this configuration, see the "NCP and VTAM Sysgen Parameters" section later in this chapter.
Figure 106 SDLLC with RSRB with Multiple 3x74s
The following configuration files describe the network shown in . The note references to the right of the configuration files refer to the "Notes" section at the end of this chapter.
Configuration for Router A
source-bridge ring-group 100source-bridge remote-peer 100 tcp 131.108.2.1source-bridge remote-peer 100 tcp 131.108.2.2source-bridge remote-peer 100 tcp 131.108.2.3!interface tokenring 0ip address 131.108.1.1 255.255.255.0source-bridge 10 1 100!interface ethernet 0ip address 131.108.2.1 255.255.255.0Configuration for Router B
source-bridge ring-group 100source-bridge remote-peer 100 tcp 11.108.2.1source-bridge remote-peer 100 tcp 11.108.2.2source-bridge remote-peer 100 tcp 11.108.2.3!interface ethernet 0ip address 131.108.2.2 255.255.255.0!interface serial 0encapsulation sdlc-primarysdlc address c1sdlc address c2sdllc traddr 0110.2222.3300 7 1 100sdllc partner 1000.5a7d.8123 c1sdllc partner 1000.5a7d.8123 c2sdllc xid c1 17200c1sdllc xid c2 17200c2Configuration for Router C
source-bridge ring-group 100source-bridge remote-peer 100 tcp 131.108.2.1source-bridge remote-peer 100 tcp 131.108.2.2source-bridge remote-peer 100 tcp 131.108.2.3!interface ethernet 0ip address 131.108.2.3 255.255.255.0!interface serial 0encapsulation sdlc-primarysdlc address c3sdllc traddr 0110.2222.3300 9 1 100sdllc partner 1000.5a7d.8123 c3 MUST MATCH TIC LOCADD, NOTE 2sdllc xid c3 17200c3 MUST MATCH VTAM IDBLK/IDNUM, NOTE 4SDLLC with RSRB and Local Acknowledgment Example
The configuration shown in enables local acknowledgment for Router B, which means that the LLC session terminates at Router A. However, the LLC2 session between Router A and Router C is not locally acknowledged and terminates at Router C.
For information about the NCP and VTAM system generation (sysgen) parameters that are used in this configuration, see the "NCP and VTAM Sysgen Parameters" section later in this chapter.
Figure 107 SDLLC with RSRB and Local Acknowledgment
The following sample configuration files describe the network shown in . (The notes in the sample configuration files refer to the "Notes" section at the end of this chapter.)
Configuration for Router A
source-bridge ring-group 100source-bridge remote-peer 100 tcp 131.108.2.1source-bridge remote-peer 100 tcp 131.108.2.2 local-acksource-bridge remote-peer 100 tcp 131.108.2.3!interface tokenring 0ip address 131.108.1.1 255.255.255.0source-bridge 1 1 100!interface ethernet 0ip address 131.108.2.1 255.255.255.0Configuration for Router B
source-bridge ring-group 100source-bridge remote-peer 100 tcp 131.108.2.1 local-acksource-bridge remote-peer 100 tcp 131.108.2.2source-bridge remote-peer 100 tcp 131.108.2.3source-bridge sdllc local-ack!interface ethernet 0ip address 131.108.2.2 255.255.255.0!interface serial 0encapsulation sdlc-primarysdlc address c1sdllc traddr 4000.3174.0b0d 7 1 100sdllc partner 1000.5a7d.8123 c1!Must match TIC LOCADD [See NOTE 2]sdllc xid c1 017200c1!Must match VTAM IDBLK/IDNUM [See NOTE 4]interface serial 1encapsulation sdlc-primarysdlc address c2sdllc traddr 0110.2222.3200 8 1 100sdllc partner 1000.5a7d.8123 c2!Must match TIC LOCADD [See NOTE 2]sdllc xid c2 017200c2!Must match VTAM IDBLK/IDNUM [See NOTE 4]Configuration for Router C
source-bridge ring-group 100source-bridge remote-peer 100 tcp 131.108.2.1source-bridge remote-peer 100 tcp 131.108.2.2source-bridge remote-peer 100 tcp 131.108.2.3!interface ethernet 0ip address 131.108.2.3 255.255.255.0!interface serial 0encapsulation sdlc-primarysdlc address c3sdllc traddr 4000.3174.0c00 9 1 100sdllc partner 1000.5a7d.8123 c3Must match TIC LOCADD [See NOTE 2]sdllc xid c3 017200c3!Must match VTAM IDBLK/IDNUM [See NOTE 4]QLLC Conversion Configuration Examples
The following sections provide QLLC conversion configuration examples:
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The examples describe four increasingly complex QLLC conversion topologies and possible software configurations for each. Following the examples are sample NCP definitions that the 37x5 FEP in these topologies could use and VTAM definitions that the IBM host in these topologies could use to reflect the routers in the communication path.
QLLC Conversion between a Single 37x5 and a Single 3x74 Example
, shown previously, illustrates the simplest QLLC conversion topology—a single 37x5 FEP on a Token Ring communicating with a single 3x74 cluster controller across an X.25 network. A router connects the Token Ring to the X.25 network. In , notice that the router's X.25 interface is treated as a virtual ring for configuration purposes.
The following configuration file configures the Cisco IOS software to support the network topology shown in :
source-bridge ring-group 100!interface serial 0encapsulation x25x25 address 31102120100x25 map qllc 0100.0000.0001 31104150101qllc srb 0100.0000.0001 201 100!! Allow the 3x74 to initiate the connection.!qllc partner 0100.0000.0001 4000.0101.0132interface tokenring 0source-bridge 1 1 100In this configuration file, the source-bridge ring-group command defines a virtual ring number 100. The serial 0 interface that connects to the X.25 network is then configured for X.25 DTE operation using the encapsulation x25 command and assigned the X.121 address of 31102120100 using the x25 address command. The x25 map qllc command associates the X.121 address of the remote X.25 device (31104150101) with a virtual Token Ring MAC address (0100.0000.0001) the Token Ring device will use to communicate with this remote X.25 device. The qllc srb command indicates that the virtual MAC address of the X.25 device will be used to communicate with the real MAC address of the Token Ring device.
The qllc partner command enables the software to open a connection to the local Token Ring device at MAC address 4000.0101.0132 on behalf of the remote X.25 device at virtual Token Ring MAC address 0100.0000.0001. The source-bridge command configures the router's Token Ring 0 interface for local source-route bridging by associating the router's virtual ring number 100 with the ring number (1) of the local Token Ring and the bridge number (1) that uniquely identifies this bridge interface.
QLLC Conversion between a Single 37x5 and Multiple 3x74s Example
shows a slightly more complex QLLC conversion topology. The same 37x5 FEP on a Token Ring connects through a router to an X.25 network, but communicates with multiple 3x74 cluster controllers through X.25.
Figure 108 QLLC Conversion between a Single 37x5 and Multiple 3x74s
The following configuration file configures the Cisco IOS software to support the network topology shown in :
source-bridge ring-group 100!interface serial 0encapsulation x25x25 address 3137005469!! configure the first 3174!x25 map qllc 0000.0cff.0001 31370054111!! 1001 - virtual ring used by all qllc devices! 100 - the virtual ring group!qllc srb 0000.0cff.0001 1001 100qllc partner 0000.0cff.0001 4000.1160.0000qllc xid 0000.0cff.0001 01710017!! configure the second 3174!x25 map qllc 0000.0cff.0002 313700543247!! 1001 - virtual ring used by all qllc devices! 100 - the virtual ring group!qllc srb 0000.0cff.0002 1001 100qllc partner 0000.0cff.0002 4000.1160.0000qllc xid 0000.0cff.0002 01710017!interface tokenring 0!! Since this is a real bridge, we have to define the way it! bridges to the Qllc virtual ring.!source-bridge 1 1 100source-bridge spanningQLLC Conversion between Multiple 37x5s and Multiple 3x74s Example
In the following example, two 3x74s on a Token Ring each attach to a different 37x5 on the other side of an X.25 network. Only one Token Ring interface is used. Do not create a bridge from the QLLC virtual ring (1001) to the physical Token Ring (1). Instead, define a virtual ring group (for example, 100).
interface serial 0encapsulation x25x25 address 3137005469!! configure the router for the first 3x74!x25 map qllc 0000.0cff.0001 31370054111!! 1001 - virtual ring used by all qllc devices! 1 - the local Token Ring number!qllc srb 0000.0cff.0001 1001 1qllc partner 0000.0cff.0001 4000.1160.0000!! configure the router for the second 3x74!x25 map qllc 0000.0cff.0002 31370053247!! 1001 - virtual ring used by all qllc devices! 1 - the local Token Ring number!! Note that the partner's MAC address and XID are different from! those in the first 3x74.!qllc srb 0000.0cff.0001 1001 1qllc partner 0000.0cff.0002 4000.1161.1234!interface tokenring 0!! Since this is a real bridge, we have to define the way it bridges! to the QLLC virtual ring.!source-bridge 1 1 1001source-bridge spanningQLLC Conversion between a Single 37x5 and Multiple 3x74s across an Arbitrary WAN Example
, shown previously, includes an added arbitrary WAN in the communication path between the 37x5 FEP and the multiple 3x74 cluster controllers. The arbitrary WAN can be a multihop network, whereas QLLC conversion treats the X.25 network as a single-hop network.
In , notice that the arbitrary WAN and the routers on either side of it form a single virtual ring, as configured using the source-bridge ring-group global configuration command.
In this configuration file, Router A uses an IP address of 131.108.2.2 and its Token Ring interface is attached to Token Ring 1. Because Router A connects to the Token Ring, it does not need to be configured for QLLC conversion. Router B, configured for QLLC conversion because it connects directly to the X.25 network through its serial interface, uses an X.121 address of 31102120100 and an IP address of 131.108.1.1. The 37x5 device uses a MAC address of 4000.0101.0132. The virtual MAC address of 0100.0000.0001 has been assigned to the 3x74 device.
Sample Configuration for Router A
The following configuration file configures the Router A in :
source-bridge ring-group 100source-bridge remote-peer 100 tcp 131.108.1.1 local-acksource-bridge remote-peer 100 tcp 131.108.2.2 local-ack!interface ethernet 0ip address 131.108.3.3 255.255.255.0!interface tokenring 0ip address 131.108.2.2 255.255.255.0source-bridge 1 1 100source-bridge spanningSample Configuration for Router B
The following configuration file configures the Router B in :
source-bridge ring-group 100source-bridge remote-peer 100 tcp 131.108.1.1 local-acksource-bridge remote-peer 100 tcp 131.108.2.2 local-acksource-bridge qllc-local-ack!interface serial 0encapsulation x25x25 address 31102120100x25 map qllc 0100.0000.0001 31104150101x25 map qllc 0100.0000.0002 31104150102qllc srb 0100.0000.0001 201 100qllc srb 0100.0000.0002 201 100!! Allow the 3174 to initiate the connection.!qllc partner 0100.0000.0001 4000.0101.0132qllc partner 0100.0000.0002 4000.0101.0132!interface ethernet 0ip address 131.108.1.1 255.255.255.0NCP and VTAM Sysgen Parameters
The sample system generation (sysgen) parameters in this section show typical NCP and VTAM values that correspond with the Router A, Router B, and Router C configurations shown in
and for SDLLC media translation and in Figure 108 for QLLC conversion.IBM's ACF/NCP uses a function called NTRI (NCP/Token Ring Interconnection) to support Token Ring-attached SNA devices. NTRI also provides translation from Token Ring-attached SNA devices (Physical Units) to switched (dial-up) devices. VTAM provides the resolution for these devices in a Switched Major Node. VTAM treats these devices on NTRI logical lines as switched devices. (For more information consult IBM documentation NCP/SSP/EP Resource Definition Reference, SC30-3448-04.)
Using SDLLC, the Cisco IOS software translates SDLC leased line protocol into Token Ring LLC2 protocol, then the NTRI function in ACF/NCP translates Token Ring LLC2 protocol into an SNA switched protocol.
NCP Generation Definitions
******************************************************************** SAMPLES BASED ON ACF/NCP V5 R4.*** NOT ALL NCP PARAMETERS ARE SHOWN****************************************************************** ****************************************************************** OPTIONS DEFINITION STATEMENT*****************************************************************NCPOPT OPTIONS NEWDEFN=YES NTRI GENERATION, MUST BE FIRST STMT******************************************************************* BUILD MACRO*****************************************************************NCPBU BUILD LOCALTO=1.5, NTRI ACK TIMER FOR LOCAL TOKEN RINGSREMOTTO=2.5, NTRI ACK TIMER FOR REMOTE TOKEN RINGSUSED IN SDLLC CONFIGURATIONS, NOTE 1******************************************************************* DYNAMIC RECONFIGURATION POOL SPACE*****************************************************************DRPOOL LUDRPOOL NUMTYP2=50 RESERVE 50 LUS ON PU. T2 PUS******************************************************************* PHYSICAL GROUP FOR NTRI TIC #1, DEFINITIONS FOR THE TOKEN RING* ADAPTER TO ESTABLISH PHYSICAL CONNECTIVITY*****************************************************************EPHYG GROUP ECLTYPE=PHYSICAL*EPHYL LINE ADAPTER=TIC2, TYPE OF ADAPTERADDRESS=(16,FULL), INTERNAL FEP TIC ADDRESSPORTADD=0,LOCADD=10005a7d8123, TIC ADDRESS, NOTE 2RCVBUFC=1440,MAXTSL=2012,TRSPEED=16 TOKEN RING SPEED*
