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This chapter describes how to configure the Cisco 7000 series mainframe Channel Interface Processor (CIP), which supports the IBM channel attach feature.
For hardware technical descriptions and information about installing the router interfaces, refer to the hardware installation and maintenance publication for your product. For command descriptions and usage information, refer to the "IBM Channel Attach Commands" chapter of the Bridging and IBM Networking Command Reference.
Support for IBM channel attach is provided on the Cisco 7000 series routers by the Channel Interface Processor (CIP) and an appropriate interface adapter card. With a CIP and the ESCON Channel Adapter (ECA) or bus-and-tag Parallel Channel Adapter (PCA), a Cisco 7000 series router can be directly connected to a mainframe, replacing the function of an IBM 3172 interconnect controller. This connectivity enables mainframe applications and peripheral access from LAN-based workstations.
A single CIP can support up to two channel adapter cards in any combination. Because of this flexibility, upgrading from parallel bus-and-tag to ESCON is simplified. The CIP can be configured for ESCON support by replacing a PCA with an ESCON adapter. Note that this upgrade procedure must be done by authorized service personnel.
The CIP provides support for the environments discussed in the following sections:
TCP/IP mainframe protocol environments for IBM operating systems Multiple Virtual Storage (MVS) and Virtual Machine (VM) are supported. This support includes TCP/IP-based applications such as terminal emulation (Telnet), the File Transfer Protocol (FTP), Simple Mail Transfer Protocol (SMTP) and Network File System (NFS), a distributed file access system. In addition, Internet Control Message Protocol (ICMP) and User Datagram Protocol (UDP) are supported.
A CIP configured with 8 megabytes (MB) of memory can support up to 128 CLAW connections, or 256 devices. Because each CLAW connection requires two devices, that allows a maximum of 128 CLAW connections per interface adapter card.
TCP/IP mainframe protocol environments for IBM operating systems MVS and VM are supported.
The CIP TCP/IP offload feature delivers the same function as the TCP/IP "offload" function on the 3172 Interconnect Controller (Model 3), but without the performance penalty. This feature implements the 3172 offload protocol for transporting application requests over the IBM ESCON or bus-and-tag channels.
All functionality provided in the CLAW environment is also supported in the TCP/IP offload environment because the function ships TCP/IP application calls over the mainframe channel using the CLAW channel protocol.
The CSNA feature provides support for SNA protocols over both ESCON and PCA interfaces to the IBM mainframe. As an IBM 3172 replacement, the CIP must support the External Communications Adapter (XCA) feature of VTAM, which allows VTAM to define Token Ring devices attached to the 3172 as switched devices.
In SNA environments, support for the XCA feature of VTAM allows the CIP to provide an alternative to front-end processors (FEPs) at sites where NCP is not required for SNA routing functions.
By providing CLS and the Logical Link Control, type 2 (LLC2) protocol stack on the CIP card, all frames destined to the CIP or from the CIP card can be fast switched by the router. The presentation of multiple "virtual" LAN media types allows the CSNA feature to take advantage of current source-route bridging (SRB), remote source-route bridging (RSRB), data-link switching plus (DLSw+), transparent bridging, SDLC-LLC2 translation (SDLLC), and Qualified Logical Link Control (QLLC) services.
The CSNA feature supports the following communication through a Cisco 7000 series router:
The CSNA feature provides SNA connectivity through the use of MAC addresses configured for internal MAC adapters on the Cisco 7000 series router. These internal MAC adapters correspond to XCA major node definitions in VTAM, providing access points (LAN gateway) to VTAM for SNA network nodes. The internal MAC adapters are configured to exist on internal LANs located on a CIP card. Each CIP card can be configured with multiple internal LANs where an internal LAN can be a Token Ring, Ethernet, or FDDI LAN. Each internal Token Ring or FDDI LAN must be configured to participate in either source-route or transparent bridging and each internal Ethernet LAN must be configured for transparent bridging. Each internal Token Ring or FDDI LAN can be configured with up to 32 internal MAC adapters. An Ethernet internal LAN can support a single internal MAC adapter. The internal MAC adapter is an emulation of LAN adapters in an IBM 3172 interconnect controller.
The TN3270 server feature on a CIP card provides mapping between an SNA 3270 host and a TN3270 client connected to a TCP/IP network as shown in Figure 127. Functionally, it is useful to view the TN3270 server from two different perspectives: SNA functions and Telnet Server functions.
Because the TN3270 server configuration is performed after an interface is configured for CSNA support, TN3270 configuration issues and tasks are addressed separately from the interface configuration tasks. The description of TN3270 configuration issues and tasks begins in the section "Configuring TN3270 on a Channel Interface Processor," later in this chapter.
You can perform the tasks in the following sections to configure and maintain IBM channel attach interfaces. In addition, several examples show how host configuration settings correlate to values used in the configuration commands.
Not all tasks are required. Your CIP image may be preloaded. You must select an interface, after which you configure the features you want supported on that interface.
See the end of this chapter for "IBM Channel Attach Interface Configuration Examples."
Because the TN3270 server configuration is performed after an interface is configured for CSNA support, TN3270 configuration issues and tasks are addressed separately from the interface configuration tasks. The of TN3270 configuration task list begins in the section "TN3270 Configuration Task List," later in this chapter.
Beginning with Cisco IOS Software Release 11.1, the CIP microcode (or CIP image) no longer is bundled with the Cisco IOS software. You must have Flash memory installed on the Route Processor (RP) card and 8 MB of RAM installed on your CIP card to use the IBM channel attach features in Cisco IOS Software Release 11.1 and later.
The CIP image is preloaded on Flash cards for all Cisco 7000 series routers ordered with the CIP option for Cisco IOS Software Release 11.1 and later. Perform the tasks in this section if you are upgrading the CIP image in your router.
To prepare the CIP, perform the following tasks beginning in privileged EXEC command mode:
| Task | Command |
|---|---|
| Copy the CIP image from a server to the Flash memory. Use the appropriate command for your system. You must be running Cisco IOS Release 11.1 or later prior to executing a copy tftp command. | copy tftp flash cipxxx-yy1 (embedded Flash) copy tftp slot0: (Flash card) copy tftp slotn: (Flash card on 7500 series router) copy tftp bootflash: (onboard Flash on 7500 series router) |
| Configure your router to load the Flash image to the CIP: Step 1 Enter global configuration mode and specify that the CIP microcode load from a Flash card in router slot n or from embedded Flash. Step 2 Load the image from Flash to the CIP card. | configure1 microcode reload |
| Exit configuration mode and display images loaded on the CIP card. | show controllers cbus2 |
Rather than as a single image (named cipxxx-yy), the CIP image appears as a directory (cipxxx-yy) that contains the various image segments to be loaded into the CIP.
The router configuration process takes longer than when using features, because the initial loading of a CIP configuration feature results in the loading of the applicable code and includes any necessary processing.
Before you configure your channel attach interface, you must select the interface. Perform the following task in global configuration mode:
| Task | Command |
|---|---|
| Select the channel attach interface and enter interface configuration mode. | interface channel slot/port |
You need not add a space between the interface type (channel) and the slot and port number. For example, you can specify interface channel 3/0 or interface channel3/0.
Use the show extended channel EXEC command to display current CIP status. This command provides a report for each physical interface configured to support IBM channel attach.
The following section describes how to configure your channel attach interface.
See the section "IBM Channel Attach Interface Configuration Examples" at the end of this chapter for example configuration commands.
The following sections describe how to configure the IBM channel attach interface for TCP/IP CLAW support. All tasks, except for configuring other interface support, are required:
See the section "Select Host System Parameters" for guidelines on matching interface configuration values with host system values.
You must configure the routing process that will be used by the Cisco IOS software. We recommend using the Enhanced IGRP routing process to perform IP routing on the IBM channel attach interface. Perform the following steps beginning in global configuration mode:
| Task | Command |
|---|---|
| Step 1 Enter router configuration mode by selecting the routing process, preferably Enhanced IGRP, and the autonomous system the router belongs to. | router eigrp process-id1 or router igrp process-id1 |
| Step 2 Define the directly connected networks that are part of the autonomous system. | network network-number1 |
You must assign an IP address to the ECA or PCA interface so that it can communicate with other devices (or tasks) on the network. The IP address you assign to the interface must be in the same subnetwork as the hosts with which you wish to communicate. Perform the following task in interface configuration mode:
| Task | Command |
|---|---|
| Assign an IP address and network mask to the selected interface. | ip address address mask1 |
You must define the devices, or tasks, supported on the interface. Some information you need to perform this task is derived from the following host system configuration files: MVSIOCP, IOCP, and the TCPIP configuration. Refer to the section "Select Host System Parameters" for guidelines on matching interface configuration values with host system values.
Perform the following task in interface configuration mode:
| Task | Command |
|---|---|
| Define the CLAW parameters for this device. | claw path device-address ip-address host-name device-name host-app device-app [broadcast] |
See the section "IBM Channel Attach Interface Configuration Examples" for samples of claw commands for different configurations.
When you configure a channel attach interface that supports a PCA card, you must define a data rate of either 3 MB per second or 4.5 MB per second. Perform the following task in interface configuration mode:
| Task | Command |
|---|---|
| Define the PCA data transfer rate. | channel-protocol [s | s4] |
To enhance the usefulness of IBM channel attach support, you can further define how the interface and the router interoperate by performing any of the following tasks in interface configuration mode:
| Task | Command |
|---|---|
| Disable fast switching (IP route cache switching). Fast switching is on by default, but access lists can inhibit fast switching. Always include this command when configuring host-to-host communications through the same ECA interface. | no ip route-cache1 |
| Use access lists to filter connections. | access-list access-list-number {permit | deny} source source-wildcard1 |
| Enable autonomous switching through either the silicon switching engine (SSE) or the CxBus controller. | ip route-cache [cbus | sse]1 or ip route-cache sse |
| Include autonomous switching support for multiple IP datagram applications running on the same CIP, as required. Always include this command when configuring host-to-host communications through the same ECA interface. | ip route-cache same-interface1 |
The following sections describe how to configure the IBM channel attach interface for TCP/IP offload support. All tasks, except for configuring other interface support, are required:
See the section "Select Host System Parameters" for guidelines on matching interface configuration values with host system values.
You must configure the routing process that will be used by the Cisco IOS software. We recommend using the Enhanced IGRP routing process to perform IP routing on the IBM channel attach interface. Perform the following steps beginning in global configuration mode:
| Task | Command |
|---|---|
| Step 1 Enter router configuration mode by selecting the routing process, preferably Enhanced IGRP, and the autonomous system the router belongs to. | router eigrp process-id1 |
| Step 2 Define the directly connected networks that are part of the autonomous system. | network network-number1 |
You must assign an IP address to the ECA or PCA interface so that it can communicate with other devices (or tasks) on the network. The IP address you assign to the interface must be in the same subnetwork as the hosts with which you wish to communicate. Perform the following task in interface configuration mode:
| Task | Command |
|---|---|
| Assign an IP address and network mask to the selected interface. | ip address address mask1 |
You must define the devices, or tasks supported on the interface. Some information you need to perform this task is derived from the following host system configuration files: MVSIOCP, IOCP, and the TCP/IP configuration. Refer to the section "Select Host System Parameters" for guidelines on matching interface configuration values with host system values.
Perform the following task in interface configuration mode:
| Task | Command |
|---|---|
| Define the offload parameters for this device. | offload path device-address ip-address host-name device-name host-app device-app host-link device-link [broadcast] |
See the section "IBM Channel Attach Interface Configuration Examples" for samples of offload commands for different configurations.
When you configure a channel attach interface that supports a PCA card, you must define a data rate of either 3 MB per second or 4.5 MB per second. Perform the following task in interface configuration mode:
| Task | Command |
|---|---|
| Define the PCA data transfer rate. | channel-protocol [s | s4] |
You can further define how the interface and the router interoperate. You can perform any of the following tasks in interface configuration mode to enhance the usefulness of IBM channel attach support:
| Task | Command |
|---|---|
| Disable fast switching (IP route cache switching). Fast switching is on by default, but access lists can inhibit fast switching. Always include this command when configuring host-to-host communications through the same ECA interface. | no ip route-cache1 |
| Use access lists to filter connections. | access-list list {permit | deny} source source-wildcard1 |
| Enable autonomous switching through either the silicon switching engine (SSE) or the CxBus controller. | ip route-cache [cbus]1 or ip route-cache sse1 |
| Include autonomous switching support for multiple IP datagram applications running on the same CIP, as required. Always include this command when configuring host-to-host communications through the same ECA interface. | ip route-cache same-interface1 |
The following sections describe how to configure the IBM channel attach interface for CSNA support. The last task, "Name the Internal Adapter," is optional. All other tasks are required.
To define the SNA channels supported by the CSNA feature, perform the following task in interface configuration mode:
| Task | Command |
|---|---|
| Define the CSNA interface. | csna path device [maxpiu value] [time-delay value] [length-delay value] |
To select an internal LAN interface, perform the following tasks beginning in global configuration mode:
| Task | Command |
|---|---|
| Step 1 Select the channel attach interface and enter interface configuration mode. | interface channel slot/2 |
| Step 2 Select the maximum number of concurrent LLC2 sessions. | max-llc2-sessions number |
| Step 3 Select the LAN interface and enter internal LAN configuration mode. | lan type lan-id |
Select the bridging characteristics for Token Ring and FDDI, or Ethernet. Perform either of the following tasks in internal LAN configuration mode:
| Task | Command |
|---|---|
| Select source-route bridging for Token Ring or FDDI. | source-bridge local-ring bridge-number target-ring1 |
| Select transparent bridging for Ethernet. | bridge-group bridge-group2 |
To configure the link characteristics of the internal LAN adapter, perform the following tasks in internal LAN configuration mode:
| Task | Command |
|---|---|
| Step 1 Enter internal adapter configuration mode. | adapter adapter-number mac-address |
| Step 2 Configure the link characteristics. | llc2 ack-delay time milliseconds1 llc2 ack-max packet-count llc2 idle-time milliseconds llc2 local-window packet-count llc2 n2 retry-count llc2 t1-time milliseconds llc2 tbusy-time milliseconds llc2 tpf-time milliseconds llc2 trej-time milliseconds llc2 xid-neg-val-time milliseconds llc2 xid-retry-time milliseconds |
Select a name for the internal adapter. Perform the following task in internal adapter configuration mode:
| Task | Command |
|---|---|
| Select a name for the internal adapter. | name name |
This section describes how to correlate values found in the VM and MVS system I/O configuration program (IOCP) files with the fields in the claw interface configuration command and the offload interface configuration command. In addition, you will need configuration information from the host TCP/IP application configuration file. Refer to the following IBM operating system manuals for specific IOCP configuration statement details:
When you define CLAW or offload parameters, you must supply path information and device address information to support routing on an IBM channel. The path information can be simple, in the case of a channel directly attached to a router, or more challenging when the path includes an ESCON director switch or multiple image facility support.
The path argument is a concatenation of three hexadecimal numbers that represent the values listed in Table 3.
| CLAW Path Argument Breakdown | Values | Description |
|---|---|---|
| Path | 01-FF | For a directly attached ESCON channel or any parallel channel, this value is 01 unless the system administrator has configured another value.
For a channel attached through an ESCON director switch, this value will be the path that, from the Cisco IOS software point of view, exits the switch and attaches to the host. |
| Channel logical address | 0-F | For a parallel channel, this value is 0. For a directly attached ESCON channel, the value may be non-zero.
If the host is running in Logical Partition (LPAR) mode and the CHPID is defined as shared, this is the partition number associated with the devices configured in the IOCP. The default for this part of the path argument is 0. Otherwise, the channel logical address associated with the channel is defined in the IOCP. |
| Control unit logical address | 0-F | For a parallel channel, this value is 0. For a directly attached ESCON channel, the value may be non-zero.
If this value is specified in the IOCP, match that value here. Otherwise, the control unit logical address is specified in the IOCP CNTLUNIT statement for the host channel in the CUADD parameter. |
In Figure 128, two host systems connect to the ESCON director switch, on paths 23 and 29. The channels both exit the switch on path 1B and attach to Router A.
Note that the path between Host A and Host B is dynamically switched within the ESCON director. A third host is attached directly to Router B through path 42. The IOCP control unit statements would look something like the following examples:
CNTLUNIT CUNUMBER=0001, PATH=(23), LINK=1B, UNITADD=((00,64)), UNIT=SCTC, CUADD=F
CNTLUNIT CUNUMBER=0002, PATH=(29), LINK=1B, UNITADD=((00,64)), UNIT=SCTC, CUADD=A
CNTLUNIT CUNUMBER=000A, PATH=(42), UNIT=SCTC, UNITADD=((00,64))
The system administrator can provide you with the values, for example 15 and 19, for the return channel attachment from the switch to each host. Given these values, the claw command path argument for the two channel attachments to Router A becomes:
claw 150F claw 190A
The offload command path argument for the two channel attachments to Router A becomes:
offload 150F offload 190A
The claw command path argument for the directly attached channel to Router B is easy to determine:
claw 0100
Similarly, the offload command path argument for the directly attached channel to Router B is as follows:
offload 0100
Next, determine the claw or offload command device-address argument value, which is shown as 00 in the UNITADD parameter for all three devices. This value can be any even value between 00 and 3E, as long as it matches an allowed UNITADD value in IOCP. The claw (or offload) commands now become:
claw 150F 00 claw 190A 00
offload 150F 00 offload 190A 00
claw 0100 02
offload 0100 02
The remainder of the claw and offload command arguments are derived from the DEVICE, LINK, and HOME statements in the host TCP/IP configuration files. The statements will be similar to the following:
DEVICE EVAL CLAW 500 VMSYSTEM C7000 NONE 20 20 4096 4096 LINK EVAL1 IP 0 EVAL HOME 198.92.2.12 EVAL1
DEVICE EVAL CLAW 600 STSYSTEM C7000 NONE 20 20 4096 4096 LINK EVAL1 IP 0 EVAL HOME 198.92.2.13 EVAL1
DEVICE EVAL CLAW 700 RDUSYSTM C7000 NONE 20 20 4096 4096 LINK EVAL1 IP 0 EVAL HOME 198.92.2.14 EVAL1
The DEVICE statement lists the host-name and device-name values to use, which follows the CLAW 500 entry in the DEVICE statement.
The LINK statement links the device name, EVAL, to EVAL1. The IP address for EVAL1 appears in the HOME statement.
Based on this example, you can supply the remainder of the arguments for the sample claw commands:
claw 150F 00 198.92.2.12 VMSYSTEM C7000 TCPIP TCPIP claw 190A 00 198.92.2.13 STSYSTEM C7000 TCPIP TCPIP
claw 0100 02 198.92.2.14 RDUSYSTM C7000 TCPIP TCPIP
Similarly, the sample offload commands are as follows:
offload 150F 00 198.92.2.12 VMSYSTEM C7000 TCPIP API offload 190A 00 198.92.2.13 STSYSTEM C7000 TCPIP API
offload 0100 02 198.92.2.14 RDUSYSTM C7000 TCPIP API
When you have a directly attached channel, the system administrator may provide you with a system IODEVICE ADDRESS that you can use. In this case, you must work backwards through the IOCP file to locate the proper device-address argument value for the claw command.
In this first example, the IODEVICE ADDRESS value is 800. Using this number, you locate the IODEVICE ADDRESS statement in the IOCP file, which points you to the CNTLUNIT statement that contains the device-address argument value for the claw or offload command:
IODEVICE ADDRESS=(0800,256),CUNUMBR=(0012),UNIT=SCTC **** Address 800 points to CUNUMBR 0012 in the following statement CNTLUNIT CUNUMBR=0012,PATH=(28),UNIT=SCTC,UNITADD=((00,256)) **** The device-address is the UNITADD value of 00
From this example, the claw or offload command would be similar to the following:
claw 0100 00 197.91.2.12 CISCOVM EVAL TCPIP TCPIP
In the next example, the system administrator has given you an IODEVICE ADDRESS of 350, which does not correspond exactly to a value in the IOCP file. In this instance you must calculate an offset device-address argument value for the claw or offload command:
IODEVICE ADDRESS=(0340,64),CUNUMBR=(0008),UNIT=SCTC IODEVICE ADDRESS=(0380,64),CUNUMBR=(0009),UNIT=SCTC **** Address 350 (340 + 10) is in the range covered by CUNUMBER 0008 CNTLUNIT CUNUMBR=0008,PATH=(24),UNIT=SCTC,UNITADD=((40,64)),SHARED=N, X **** The device-address is the UNITADD value of 40, offset by 10 **** The device-address to use is 50
From this example, the claw or offload command would be similar to the following:
claw 0100 50 197.91.2.12 CISCOVM EVAL TCPIP TCPIP
 | Caution When you are running MVS, you must disable the missing interrupt handler (MIH) to avoid introducing errors into the CLAW algorithm. Refer to the IBM publication Transmission Control Protocol/Internet Protocol TCP/IP Version 2 Release 2.1 for MVS: Planning and Customization (publication SC31-6085 or later) for information on disabling the MIH. |
You can perform the tasks in the following sections to monitor and maintain the interfaces:
The software allows you to display information about the interface, including the version of the software and the hardware, the controller status, and statistics about the interfaces. The following table lists some of the interface monitoring tasks. To display the full list of show commands, enter show ? at the EXEC prompt.
Perform the following commands in privileged EXEC mode:
| Task | Command |
|---|---|
| Display information about the CIP interfaces on the Cisco 7000 series. These commands display information that is specific to the interface hardware. | show extended channel slot/port csna [admin | oper | stats] [path [device-address]]
show extended channel slot/port icmp-stack [ip-address] show extended channel slot/port ip-stack [ip-address] show extended channel slot/port llc2 [admin | oper | stats] [lmac [lsap [rmac [rsap]]]] show extended channel slot/port statistics [path [device-address]] show extended channel slot/port subchannel show extended channel slot/port tcp-stack [ip-address] show extended channel slot/port udp-listeners [ip-address] show extended channel slot/port udp-stack [ip-address] show interfaces channel slot/port [accounting] |
| Display current internal status information for the interface controller cards in the Cisco 7000 series. |
|
|
Display the number of packets for each protocol type that has been sent through the interface for the Cisco 7000 series. | show interfaces channel [slot/port] |
| Display the hardware configuration, software version, names and sources of configuration files, and boot images. | show version2 |
To clear the interface counters shown with the show interfaces command, enter the following command in EXEC mode:
| Task | Command |
|---|---|
| Clear interface counters for the Cisco 7000. | clear counters [type slot/port]1 |
Complete the following task in EXEC mode to clear and reset interfaces. Under normal circumstances, you do not need to clear the hardware logic on interfaces.
| Task | Command |
|---|---|
| Reset the hardware logic on an interface. | clear interface type number1 |
You can disable an interface. Doing so disables all functions on the specified interface and marks the interface as unavailable on all monitoring command displays. This information is communicated to other network servers through all dynamic routing protocols. The interface will not be mentioned in any routing updates. On the CIP with an ECA interface adapter, a command is sent to the host to inform it of the impending shutdown. On the CIP with a PCA interface adapter, the shutdown command disables the adapter card's transceivers and the PCA stops responding to all commands. A select-out bypass relay must be manually set at the cable connecting to the PCA.
One reason to shut down an interface is if you want to change the interface type of a Cisco 7000 port online. To ensure that the system recognizes the new interface type, shut down the interface, then reenable it after changing the interface. Refer to your hardware documentation for more details.
To shut down an interface and then restart it, perform the following tasks in interface configuration mode:
| Task | Command |
|---|---|
| Shut down an interface. | shutdown1 |
| Reenable an interface. | no shutdown1 |
To check whether an interface is disabled, use the EXEC command show interfaces. An interface that has been shut down is shown as administratively down in the show interfaces command display.
The CIP does not provide software loopback support. You can use special loopback wrap plugs to perform hardware loopback with the ECA and PCA interface cards. Hardware loopback information is included in the hardware installation notes for the CIP.
The following sections describe additional features of TN3270 server support on the CIP. The features discussed include the following:
You will also need to understand the following information before proceeding with TN3270 configuration tasks:
This will be the most common form of request from TN3270 clients emulating a TN3270 terminal. The user typically wants to specify emulating a particular terminal type and normally is not interested in what LOCADDR or LU name is allocated by the host, as long as a network solicitor logon menu is presented. The server will perform the following on such a session request:
When VTAM receives the NMVT, it will use the EBCDIC model type and number string to look up an LU template under the LUGROUP. For example, the string "327802E" will find a match in the sample configuration shown in Figure 129. An ACTLU will be sent and a terminal session with the model and type requested by the client can be established.
VTAM requires a model type and number from the Reply PSID NMVT to use as a key to look up in the LU group to find an LU template. The model type is a four character string; the model number is a two or three character string. The server will accept the following formats of terminal type string from the client:
A complication arises with TN3270E clients that request a copy of the Bind Image. Such clients require SCS datastream on the SSCP-LU flow. All other clients require 3270 datastream on that flow. Therefore, these two kinds of client must be directed to different LUGROUP entries at the host. To make this as easy as possible, the SCS requirement is also encoded into the model string sent to the host. Following the previously described terminal type string formats accepted by the server, this additional condition is applied:
| String from Client (ASCII) | BIND-IMAGE Requested? | String to Host (EBCDIC) |
|---|---|---|
| IBM-3278-4 | No | 327804 |
| IBM-3279-5E | No | 327905E |
| IBM-3279-3-E | Yes | 3279S5E |
| IBM-DYNAMIC | Yes | DYNASIC |
| ABC | Yes | ABCS |
| ABCDEFGH | Yes | ABCDSFG |
A TN3270E client can request a specific LU name by using the TN3270E command CONNECT as documented in RFC 1647. The name requested must match the name by which the TN3270 server knows the LU (see the section "LU Names in the TN3270 Server"), and the host must have activated the LU (with ACTLU).
Where SNA session switching is configured (that is, on DLUR PUs) the TN3270 server learns the LU names from the ACTLUs.
For direct PUs, a "seed" name can be configured on the PU. TN3270 server uses this name in conjunction with the LOCADDRS to generate names for the LUs. It is best to use the same naming convention as the host.
An end node DLUR function is implemented as part of the TN3270 server. The purpose of the DLUR is to allow the routing of TN3270 LUs to multiple VTAM hosts to be performed in the CIP card rather than on the VTAM hosts. The need for this feature will increase with the introduction of the new multi-CPU CMOS mainframe which comprises up to 16 CPUs that appear as separate VTAMs.
The implementation of TN3270 server LUs under DLUR also allows the server to learn about the LU names on the ACTLU, which greatly simplifies the configuration to support specifically requestable LUs such as printers.
The TN3270 server supports access to multiple hosts via the configuration on a PU basis (Table 5). PUs connected to different hosts/applications can be configured with different IP address.
| Command | PU Name | Idblk | Ip-address | Type | Adapter number | Lsap | RMAC | Rmac | Lu-seed | Lu-name |
|---|---|---|---|---|---|---|---|---|---|---|
| PU | X1 | 05D30001 | 192.195.80.40 | tok | 1 | 4 | RMAC | 4100.cafe.0001 | lu-seed | TN3X1### |
| PU | X2 | 05D30002 | 171.69.176.43 | tok | 1 | 8 | RMAC | 4100.cafe.0002 | lu-seed | TN3X2### |
From the pu (direct) TN3270 configuration command values shown in Table 5, PU X2 establishes a link to a host at SAP 4 (the default) on MAC address 4100.cafe.0002. A client connecting to IP address 171.69.176.43 is allocated an LU from that PU and is routed to that host.
Note that by using the DLUR function, all the LUs in the server can be defined and owned by a controlling VTAM. When a client requests an application residing on a different VTAM host, the controlling VTAM will issue the request to the target host which will send a BIND directly to the client. All LU-LU data will then flow directly between the target host and the client without needing to go through the controlling VTAM.
Other non-Cisco implementations of TN3270 support depend on predefined, static pools of LUs to support different terminal types requested by the TN3270 clients. The CIP TN3270 server implementation removes the static nature of these configurations by using a VTAM release 3.4 feature, dynamic definition of dependent LU (DDDLU). (Refer to the VTAM operating sysetm manuals for your host system, under the descriptions for LUGROUP for additional information.) DDDLU dynamically requests LUs using the terminal type provided by TN3270 clients. The dynamic request eliminates the need to define any LU configuration in the server to support TN3270 clients emulating a generic TN3270 terminal.
To support DDDLU, the PUs used by the TN3270 server have to be defined in VTAM with LUSEED and LUGROUP parameters as shown in Figure 129.
Example VTAM host values defining LUSEED and LUGROUP name parameters: | ||||
| TN3270PU | PU | .
IDBLK=05D, IDNUM=30001, | * | define other PU parameters |
| LUSEED=TN3X1###, | * | define the seed component of the LU names created by DDDLU (e.g. LOCADDR 42 will have the name TN3X1042) | ||
| LUGROUP=AGROUP | * | define the LU group name | ||
| * | ||||
| TN3X1100 | LU | LOCADDR=100,
MODETAB=AMODETAB | * | define a terminal which requires a specific LU name |
| * | ||||
| TN3X1101 | LU | LOCADDR=101,
DLOGMODE=M3287CS | * | define a printer which requires a specific LU name |
Example VTAM host values defining LUGROUPname, AGROUP: | ||||
| AGROUP | LUGROUP | * | define LU group to support various terminal types | |
| 327802E | LU | USSTAB=USSXXX,
LOGAPPL=TPXP001, DLOGMOD=SNX32702, SSCPFM=USS3270 | * | define template to support IBM 3278 terminal model 2 with Extended Data Stream. Note that the USS messages in USSXXX should be in 3270 datastream. |
| 3278S2E | LU | USSTAB=USSYYY,
LOGAPPL=TPXP001, DLOGMOD=SNX32702, SSCPFM=USSSCS | * | define template to support IBM 3278 terminal model 2 with Extended Data Stream, for TN3270E clients requesting BIND-IMAGE. |
| 327805 | LU | USSTAB=USSXXX,
LOGAPPL=TPXP001, DLOGMOD=D4C32785, SSCPFM=USS3270 | * | define template to support IBM 3279 terminal model 5 |
| @ | LU | USSTAB=USSXXX,
LOGAPPL=TPXP001, DLOGMOD=D4A32772, SSCPFM=USS3270 | this is the default template to match any other terminal types | |
With the configuration shown inFigure 129 defined in the host, the ACTPU sent by VTAM for the PU TN3270PU will have the "Unsolicited NMVT Support" set in the system services control point (SSCP) capabilities control vector. This allows the PU to dynamically allocate LUs by sending network management vector transport (NMVT) with a "Reply Product Set ID" control vector.
After the TN3270 server sends a positive response to the ACTPU, it will wait for VTAM to send ACTLUs for all specifically defined LUs. In the sample configuration shown in Figure 129, ACTLUs will be sent for TN3X1100 and TN3X1101. The server sends a positive response and sets SLU DISABLED. The LOCADDR of these LUs are put into the specific LU cache and reserved for specific LU name requests only.
To allow sufficient time for the VTAM host to send all the ACTLUs, a 30-second timer is started and restarted when an ACTLU is received. When the time expires, it is assumed all ACTLUs defined in VTAM for the PU have been sent. All LUs that have not been activated are available in a generic LU pool to be used for DDDLU unless they have been reserved by the configuration using the generic-pool deny TN3270 configuration command.
After the VTAM activation, the server can support session requests from clients using dynamic or specific LU allocation.
The TN3270 configuration modes and router command prompts are described in the following sections and displayed in Figure 130. The TN3270 server can be configured only on Port 2, the internal LAN port, of a CIP card.
Some configuration commands create entities on the CIP. For most of these, the command changes to the mode associated with that entity (for example, a PU). In general, the parameters provided to create the entity come in two sets: those which identify the specific instance of the entity (for example, a PU name) and those that merely set operating parameters. To return to the mode later, the same command is used but with only the first set of parameters. The following example tasks clarify how to return to a command mode without necessarily creating a new entity:
To create a DLUR LSAP and enter DLUR LSAP configuration mode, perform the following task beginning in TN3270 DLUR configuration mode:
| Task | Command |
|---|---|
| Create a DLUR LSAP and enter DLUR LSAP configuration mode. | lsap token-adapter 1 84 |
To return later to the DLUR LSAP configuration mode on the same entity, perform the following task beginning in TN3270 DLUR configuration mode:
| Task | Command |
|---|---|
| Enter DLUR LSAP configuration mode on the same LSAP. | lsap token-adapter 1 |
To remove an entity, the same identification parameters are needed. Perform the following task beginning in TN3270 DLUR configuration mode:
| Task | Command |
|---|---|
| Remove a previously defined DLUR LSAP entity. | no lsap token-adapter 1 |
TN3270 configuration modes described in this section include the following:
From interface configuration mode, tn3270-server command puts you in TN3270 server configuration mode.
Prompt:
tn3270-server>
From TN3270 server configuration mode, the dlur command puts you in DLUR configuration mode.
Prompt:
tn3270-dlur>
From DLUR server configuration mode, lsap command puts you in DLUR SAP configuration mode.
Prompt:
tn3270-dlur-lsap>
There are two paths to PU configuration mode: from the TN3270 server configuration mode, or from the DLUR configuration mode. In either mode, the pu command puts you in PU configuration mode.
From TN3270 configuration mode, the pu command to create a new PU is:
pu pu-name idblk-idnum ip-address type adapno lsap [rmac rmac] [rsap rsap] [lu-seed lu-name-stem]From DLUR configuration mode, the pu command to create a new PU is:
pu pu-name idblk-idnum ip-addressFrom either mode, to return to PU configuration mode on PU pu-name the command is:
pu pu-namePrompts:
tn3270-pu> tn3270-dlur-pu>
The following commands are valid in TN3270 configuration mode, or in either variation of PU configuration mode:
[no] tcp-port port-number [no] idle-time seconds [no] keepalive seconds [no] unbind-action {keep | disconnect} [no] generic-pool {permit | deny} [no] shutdownValues entered in PU configuration mode override settings made in TN3270 configuration mode. In addition, the no form of these commands entered in PU configuration mode will restore the command value entered in TN3270 command mode.
The following sections describe how to configure TN3270 server support on the CIP. Not all tasks are required. Refer to "TN3270 Configuration Example" for configuration examples.
When the host site uses APPN and the TN3270 server can reach multiple hosts, we recommend you use DLUR and configure your PUs under DLUR. In this instance, perform the following tasks:
When the host site does not use APPN, you configure your PU parameters for a directly-connected host. In this instance, perform the following tasks:
CIP SNA support (CSNA) must be configured prior to configuring TN3270 support. Refer to the section "Configure IBM Channel Attach for CSNA Support," earlier in this chapter.
After you have configured CSNA support, you proceed with TN3270 configuration.
This task is required. To establish a TN3270 server on the internal LAN interface on the CIP, perform the following tasks beginning in global configuration mode:
| Task | Command |
|---|---|
| Select the channel attach internal LAN interface and enter interface configuration mode. | interface channel slot/2 |
| Specify a TN3270 server on the internal LAN interface and enter TN3270 configuration mode. | tn3270-server |
| (Optional) Configure maximum number of LUs allowed. | maximum-lus max-number-of-lu-allocated |
| (Optional) Configure transmission of a WILL TIMING-MARK. | timing-mark |
| (Optional) Assign a TCP port other than the default of 23. This command is also available in PU configuration mode. | tcp-port port-nbr |
| (Optional) Specify the idle time for server disconnect. This command is also available in PU configuration mode. | idle-time num-of-seconds |
| (Optional) Specify the maximum time allowed between keepalive marks before the server disconnects. This command is also available in PU configuration mode. | keepalive num-of-seconds |
| (Optional) Specify whether the TN3270 session will disconnect when an UNBIND command is received. This command is also available in PU configuration mode. | unbind-action {keep | disconnect} |
| (Optional) Select whether "left-over" LUs can be used from a generic LU pool. This command is also available in PU configuration mode. | generic-pool {permit | deny} |
When you use the tn3270-server command, you enter TN3270 configuration mode and can use all other commands in the task list. You can later override many configuration values you enter in TN3270 configuration mode from PU configuration mode. On IBM host systems, these types of commands are often referred to as "sift down" commands because their values can sift down through several levels of configuration and can be optionally altered at each configuration level.
This task is required when configuring PUs that do not use DLUR. To configure PU parameters for the TN3270 server, perform the following tasks beginning in TN3270 configuration mode:
| Task | Command |
|---|---|
| Enter PU configuration mode and create or delete PUs with direct host links. | pu pu-name idblk-idnum ip-address type adapno lsap [rmac rmac] [rsap rsap] [lu-seed lu-name-stem] |
| (Optional) Assign a TCP port other than the default of 23. This command is also available in TN3270 configuration mode. | tcp-port port-nbr |
| (Optional) Specify the idle time for server disconnect. This command is also available in TN3270 configuration mode. | idle-time num-of-seconds |
| (Optional) Specify the maximum time allowed between keepalive marks before the server disconnects. This command is also available in TN3270 configuration mode. | keepalive num-of-seconds |
| (Optional) Specify whether the TN3270 session will disconnect when an UNBIND command is received. This command is also available in TN3270 configuration mode. | unbind-action {keep | disconnect} |
| (Optional) Select whether "left-over" LUs can be used from a generic LU pool. This command is also available in TN3270 configuration mode. | generic-pool {permit | deny} |
When you use the pu command, you enter PU configuration mode and can use all other commands in this task list. Configuration values you enter in PU configuration mode will override other values entered while in TN3270 configuration mode. In addition, you can enter PU configuration mode from DLUR configuration mode when configuring PUs that are connected by means of DLUR.
If you are configuring PUs for directly connected hosts, you need not perform any additional configuration tasks.
This task is required when configuring DLUR connected hosts. To configure DLUR parameters for the TN3270 server, perform the following tasks beginning in TN3270 configuration mode:
| Task | Command |
|---|---|
| Create a DLUR function in the TN3270 server and enter DLUR configuration mode. | dlur fq-cpname fq-dlusname |
| (Optional) Specify the fallback choice for the DLUR DLUS. | dlus-backup dlusname2 |
| (Optional) Specify the preferred network node (NN) server. | preferred-nnserver NNserver |
To configure SAPs under the DLUR function, perform the following tasks beginning in DLUR configuration mode:
| Task | Command |
|---|---|
| Create a SAP function under DLUR and enter DLUR SAP configuration mode. | lsap type adapno [lsap] |
| (Optional) Identify an APPN virtual routing node (VRN). | vrn vrn-name |
| (Optional) Create named links to hosts. A link should be configured to each potential NN server. (The alternative is to configure the NN servers to connect to DLUR.) If VRN is used it is not necessary to configure links to other hosts. Do not configure multiple links to the same host. | link name [rmac rmac] [rsap rsap] |
This task is required when configuring DLUR connected hosts. To configure PUs under the DLUR function, perform the following tasks beginning in DLUR configuration mode:
| Task | Command |
|---|---|
| Create a PU function under DLUR and enter PU configuration mode. | pu pu-name idblk-idnum ip-address |
| Assign a TCP port other than the default of 23. | tcp-port port-nbr |
| Specify the idle time for server disconnect. | idle-time num-of-seconds |
| Specify the maximum time allowed between keepalive marks before the server disconnects. | keepalive num-of-seconds |
| Specify whether the TN3270 session will disconnect when an UNBIND command is received. | unbind-action {keep | disconnect} |
| Select whether "left-over" LUs can be used from a generic LU pool. | generic-pool {permit | deny} |
The pu command entered in DLUR configuration mode has different parameters than when it is entered from TN3270 configuration mode.
The following table lists some of the monitoring tasks specific to the TN3270 server. To display the full list of show commands, enter show ? at the EXEC prompt.
Use the following commands in privileged EXEC mode:
| Task | Command |
|---|---|
| Display the current server configuration parameters and the status of the PUs defined in each server. | show extended channel tn3270-server |
| Display the PU configuration parameters, statistics and all the LUs currently attached to the PU. | show extended channel tn3270-server pu-name |
| Display the status of the LU. | show extended channel tn3270-server pu-name lu lu-number [history] |
| Display the information about LUs that are defined under an IP address. | show extended channel tn3270-server client-ip-address ip-address |
| Display information about the DLUR components. | show extended channel tn3270-server dlur |
The following sections include examples to help you understand some aspects of interface configuration:
The following example configures an Enhanced IGRP routing process in autonomous system 127 and defines two networks to be advertised as originating within that autonomous system:
router eigrp 127 network 197.91.2.0 network 197.91.0.0
The following example assigns an IP address and network mask to the IBM channel attach interface on the router:
ip address 197.91.2.5 255.255.255.0
The following example configures the IBM channel attach interface to support a directly connected device:
claw 0100 00 197.91.0.21 VMSYSTEM C7000 TCPIP TCPIP
The following example consists of the mainframe host profile statements, buffer poolsize recommendations, and router configuration statements for the network shown in Figure 131.
; Device statement DEVICE OFF CLAW 762 CISCOVM CIP1 NONE 20 20 4096 4096 ; Link Statements (both needed) LINK OFFL OFFLOADLINK1 1 OFF LINK MEMD OFFLOADAPIBROAD 162.18.4.59 OFF OFFL ; Home Statement ; (No additional home statements are added for offload) ; Routing information (if you are not using the ROUTED SERVER) GATEWAY ; NETWORK FIRST HOP DRIVER PCKT_SZ SUBN_MSK SUBN_VALUE 162.18 = MEMD 4096 0.0.255.248 0.0.4.56 DEFAULTNET = MEMD 1500 0 ;START statements START OFF
See the IBM TCP/IP Performance Tuning Guide (SC31-7188-00) for buffer size adjustments.
The following statements configure the offload feature in the router. When you configure an host-to-host communication through the same ECA adapter, include the no ip redirects and ip route-cache same-interface commands:
interface Channel0/0 ip address 162.18.4.57 255.255.255.248 no ip redirects ip route-cache same-interface ip route-cache cbus no keepalive offload C300 62 162.18.4.59 CISCOVM CIP1 TCPIP TCPIP TCPIP API
The following configuration shows how to configure CSNA in a Cisco 7000 channel-attached router. This configuration example accommodates the router configuration illustrated in Figure 132.
source-bridge ring-group 2 source-bridge remote-peer tcp 198.92.0.122 source-bridge remote-peer tcp 198.92.0.123 interface serial 1/0 ip address 198.92.0.122 255.255.255.0 clockrate 56000 interface tokenring 2/0 mac-address 400070000411 no ip address ring-speed 16 source-bridge active 101 1 2 source-bridge spanning interface ethernet 3/0 mac-address 020070000412 no ip address bridge-group 1 interface fddi 4/0 mac-address 400070000413 no ip address source-bridge 102 1 2 interface channel 0/0 csna 0100 80 csna 0100 81 interface channel 0/1 csna 0100 40 csna 0100 41 time-delay 30 length-delay 4096 interface channel 0/2 max-llc2-sessions 2048 lan tokenring 0 source-bridge 1000 1 2 adapter 0 4000.0000.0401 adapter 1 4000.0000.0402 llc2 N2 3 llc2 t1-time 2000 lan tokenring 1 source-bridge 1001 1 2 adapter 2 4000.0000.0401 adapter 3 4000.0000.0403 llc2 N2 3 llc2 t1-time 2000 lan ethernet 0 bridge-group 1 adapter 0 4000.0000.0C01 lan fddi 0 source-bridge 1002 1 2 adapter 0 4000.0000.0D01 bridge 1 protocol ieee
The following example turns off the CIP interface in slot 2 at port 0:
interface channel 2/0 shutdown
The following example enables the CIP interface in slot 3 at port 0 that had been previously shut down:
interface channel 3/0 no shutdown
The following configuration has three PUs using DLUR and two more with direct connections.
The initial CIP configuration is as follows:
interface Channel2/2 ip address 10.10.20.126 255.255.255.128 no ip redirects no ip directed-broadcast ip pim query-interval 0 ip igmp query-interval 0 no ip route-cache no keepalive no clns checksum clns congestion-threshold 0 clns erpdu-interval 0 clns rdpdu-interval 0 no clns route-cache no clns send-erpdu no clns send-rdpdu lan TokenRing 0 source-bridge 223 1 2099 adapter 0 4100.cafe.0001 llc2 N1 2057 adapter 1 4100.cafe.0002 llc2 N1 2057
Configuration dialog to configure the TN3270 function follows:
! HOSTA is channel-attached and will open SAP 8 on adapter 0. ! HOSTB is reached via token-ring ! HOSTC is channel-attached non-APPN and will open SAP 4 on adapter 0. ! enter interface configuration mode for the virtual interface in slot 2 router(config)#int channel 2/2 ! create TN3270 Server entity router(config-if)#tn3270-server ! set server-wide defaults for PU parameters router(cfg-tn3270)#keepalive 0 router(cfg-tn3270)#unbind-action disconnect router(cfg-tn3270)#generic-pool permit ! define DLUR parameters and enter DLUR configuration mode router(cfg-tn3270)#dlur SYD.TN3020 SYD.VMG ! create PUs under DLUR ! Note that the first two share an IP address router(tn3270-dlur)#pu pu0 05d99001 10.10.20.1 router(tn3270-dlur-pu)#pu pu1 05d99002 10.10.20.1 router(tn3270-dlur-pu)#pu pu2 05d99003 10.10.20.2 ! create a DLUR LSAP and enter DLUR LSAP configuration mode router(tn3270-dlur-pu)#lsap token-adapter 1 ! specify the VRN name of the network containing this lsap router(tn3270-dlur-lsap)#vrn syd.lan4 ! create a link from this lsap router(tn3270-dlur-lsap)#link hosta rmac 4100.cafe.0001 rsap 8 router(tn3270-dlur-lsap)#link hostb rmac 4000.7470.0009 rsap 4 router(tn3270-dlur-lsap)#exit router(tn3270-dlur)#exit ! create direct pus for the non-APPN Host ! note that they must use different lsaps because they go to the same Host router(cfg-tn3270)#pu pu3 05d00001 10.10.20.5 tok 1 24 rmac 4100.cafe.0001 lu-seed pu3### router(tn3270-pu)#pu pu4 05d00002 10.10.20.5 tok 1 28 rmac 4100.cafe.0001 lu-seed pu4### router(tn3270-pu)#end
The resulting configuration from the initial configuration and the configuration dialog follows:
interface Channel2/2
ip address 10.10.20.126 255.255.255.128
no ip redirects
no ip directed-broadcast
ip pim query-interval 0
ip igmp query-interval 0
no ip route-cache
no keepalive
no clns checksum
clns congestion-threshold 0
clns erpdu-interval 0
clns rdpdu-interval 0
no clns route-cache
no clns send-erpdu
no clns send-rdpdu
lan TokenRing 0
source-bridge 223 1 2099
adapter 0 4100.cafe.0001
llc2 N1 2057
adapter 1 4100.cafe.0002
llc2 N1 2057
tn3270-server
pu PU3 05D00001 10.10.20.5 token-adapter 1 24 rmac 4100.cafe.0001 lu-seed PU3###
pu PU4 05D00002 10.10.20.5 token-adapter 1 28 rmac 4100.cafe.0001 lu-seed PU4###
dlur SYD.TN3020 SYD.VMG
lsap token-adapter 1
vrn SYD.LAN4
link HOSTB rmac 4000.7470.0009
link HOSTA rmac 4100.cafe.0001 rsap 08
pu PU0 05D99001 10.10.20.1
pu PU1 05D99002 10.10.20.1
pu PU2 05D99003 10.10.20.2
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