Configuring the TN3270 Server

This information is described in the following sections:

The TN3270 server provides the following benefits:

The TN3270 server feature offers an attractive solution when the following conditions need to be supported in an SNA environment:

• Maintaining an IP backbone while providing support for SNA 3270-type clients.

• Offloading mainframe CPU cycles when using a TN3270 host TCP/IP stack with a TN3270 server.

• Providing support for high session density or high transactions per second.

The LUs implemented by the TN3270 server are dependent LUs. To route these dependent LU sessions to multiple VTAM hosts connected to the TN3270 server in the CMCC adapter card, rather than routing in the VTAM hosts, the TN3270 server implements a SNA session switch with end node (EN) dependent LU requester (DLUR) function. SNA session switching allows you to eliminate SNA subarea routing between hosts of TN3270 traffic by establishing Advanced Peer-to-Peer Networking (APPN) links with the primary LU hosts directly.

Using the DLUR function is optional so that the TN3270 server can be used with VTAM versions prior to version 4.2, which provide no APPN support. In these non-APPN environments, access to multiple hosts is accomplished using direct PU configuration in the TN3270 server.

Unless the TN3270 server uses a Token Ring connection to a front-end processor (FEP), or other LLC connectivity to the mainframe host, it will require CSNA or CMPC support. For more information about configuring CSNA or CMPC support, see the "Configuring CSNA and CMPC" chapter in this publication.

Alternatively, you can use the TN3270 server on a remote router as an intermediate step toward using the CIP or CPA as a direct host connection. In this case, the TN3270 server resides on a router that is connected to the mainframe using a channel connection device, such as the FEP or a CIP or CPA.

The TN3270 server feature is implemented on the following CMCC adapters:

• CIP---Installed in a Cisco 7000 with RSP7000 or 7500 series router. Each CIP has up to two ESCON or two bus-and-tag (parallel) interfaces and a single virtual interface. The TN3270 server is installed on the virtual interface. Therefore, each CIP can have a single TN3270 server.

• CPA---ECPA or PCPA installed in a Cisco 7200 series router. Each CPA combines the function of an ESCON interface and a virtual interface on a single interface. As with the CIP, a single TN3270 server can be installed on each CPA.

Because a router can accommodate more than one CIP or CPA, each router can support multiple TN3270 servers.

• Direct PUs---Used in subarea SNA

• DLUR PUs---Used with APPN

Direct PUs and DLUR PUs can coexist on the same CIP or CPA. Both types of PUs support either static or dynamic LUs. However, the LU type is defined only in VTAM and is not explicitly defined in the TN3270 server.

With direct PUs, the LU names in the TN3270 server do not necessarily match the LU names defined in VTAM. However, there are a couple of ways to accomplish matching LU names for direct PUs:

The type of LU that is allocated is defined only in the VTAM switched major node. The TN3270 server does not specify the LU type.

When using the lu-seed parameter in the TN3270 server configuration, it is best to use the same naming convention as the host to prevent situations where the LU name that the TN3270 server recognizes differs from the corresponding LU name assigned in VTAM.

Several factors determine how LUs are assigned and named. For more information about the different factors that influence LU naming, see the TN3270 Design and Implementation Guide available on CCO.

The TN3270 server translates the following formats of terminal type string from a client:

• IBM-<XXXX>-<Y>[-E]: Specifies "XXXX0Y"or "XXXX0YE" in the model type and number field of the Reply PSID NMVT.

Note The "E" in the model string refers to 3270 Extended Datastream. It has no association with the "E" in "TN3270E."

• IBM-DYNAMIC: Specifies "DYNAMIC" in the model type and number field of the Reply PSID NMVT. The VTAM configuration also must have "DYNAMIC" defined as a template in the LUGROUP.

All other terminal strings that do not match the above syntax examples are forwarded as is to VTAM. For example, a string of "IBM-ZZ..Z," where "ZZ..Z" does not match the preceding syntax, is forwarded as "ZZ..Z."

In all cases, the string is translated from ASCII to EBCDIC and truncated at seven characters.

TN3270 clients can also use static LUs if client nailing is configured on the TN3270 server.

The TN3270 server performs the following functions with this type of session request:

Using LU nailing, clients from traditional TN3270 (non-TN3270E) devices can connect to specific LUs, which overcomes a limitation of TN3270 devices that cannot specify a "CONNECT LU." LU nailing is useful for TN3270E clients because it provides central control of your configuration at the router rather than at the client.

For example, the following LUs are nailed to clients at address 192.195.80.40, and LUs BAGE1004 and BAGE1005, which were connected but are now disconnected.

lu    name   client-ip:tcp       nail state    model   frames in out    idle for
1   BAGE1001 192.195.80.40:3822   Y   P-BIND   327904E  4       4       0:22:35
2   BAGE1002 192.195.80.40:3867   Y   ACT/SESS 327904E  8       7       0:21:20
3   BAGE1003 192.195.80.40:3981   Y   ACT/SESS 327803E  13      14      0:10:13
4   BAGE1004 192.195.80.40:3991   Y   ACT/NA   327803E  8       9       0:0:7
5   BAGE1005 192.195.80.40:3997   Y   ACT/NA   327805   8       9       0:7:8
 

If a client at IP address 192.195.80.40 requests a terminal model of type IBM-3278-5, LU BAGE1005 will be selected over BAGE1004.

lu    name   client-ip:tcp       nail state    model   frames in out    idle for
1   BAGE1001 192.195.80.40:3822   Y   P-BIND   327904E  4       4       0:23:29
2   BAGE1002 192.195.80.40:3867   Y   ACT/SESS 327904E  8       7       0:22:14
3   BAGE1003 192.195.80.40:3981   Y   ACT/SESS 327803E  13      14      0:11:7
4   BAGE1004 192.195.80.40:3991   Y   ACT/NA   327803E  8       9       0:1:1
5   BAGE1005 192.195.80.40:4052   Y   ACT/SESS 327805   13      14      0:0:16

• 1st character---Alphabetic (A-Z) and national characters `@', `#', and `$'

• 2nd-8th characters---Alphabetic (A-Z), numeric (0-9), and national characters `@', `#', and `$'

These naming rules are enforced by the TN3270 server when configuring a pool name and when processing the name received on a CONNECT request from the client. The TN3270 server rejects an invalid name and truncates the name received in the CONNECT request from the client to eight characters or at an invalid character (whichever comes first) when processing the CONNECT request.

If the client sends an ASSOCIATE request for a resource name to the TN3270 server, the server provides the client with a resource LU name.

When the client criteria is processed, the TN3270 server assigns the first available LU in the group to the client. If an appropriate LU is not found, the TN3270 connection is closed.

• The first client with an IP address that is nailed to a pool connects to the TN3270 server---A cluster is reserved for that client IP address. The first appropriate LU in the cluster that satisfies the client connection request is assigned.

• A client, with the same nailed IP address as a currently connected client, connects to the TN3270 server.

  • Depending on the type of LU requested by the client (screen or printer LU), the first available screen or printer LU within a cluster that is reserved for that nailed IP address is allocated.

  • If there is not an available screen or printer LU in an assigned cluster for the client connection, a new cluster is reserved for clients with that IP address. Then, the first appropriate LU in the cluster that satisfies the client connection request is assigned.

• A client, with a new IP address that is nailed to the same pool as other clients, connects to the TN3270 server---The next available cluster is reserved for that client IP address.

• A client requests a specific pool when connecting to the TN3270 server, but the client IP address is not nailed to the pool---The first available LU in the generic pool is allocated to the client.

The termself keyword for the lu termination command orders termination of all sessions and session requests associated with an LU when a user turns off the device or disconnects from the server. This is an important feature for applications such as IBM's Customer Information Control System (CICS).

If you use an UNBIND request for session termination with CICS, Virtual Telecommunication Access Method (VTAM) security problems can arise. When CICS terminates a session from an UNBIND request, the application may reestablish a previous user's session with a new user, who is now assigned to the same freed LU.

The lu deletion command specifies whether the TN3270 server sends a REPLY-PSID poweroff request to VTAM when a client disconnects. This command is recommended in host environments running VTAM version 4.4.1. Previous versions of VTAM are not compatible with Network Management Vector Transport (NMVT) REPLY-PSID.

• The client logs off the LU-LU session and the LU is configured to disconnect on UNBIND.

• The client disconnects at the TCP layer.

• The client is idle too long or will not respond to a DO TIMING MARK message.

Any of the above conditions cause the server to do one of the following, depending upon how the lu termination command is configured:

The first response-time bucket counts transactions with total response times that are less than or equal to boundary 1 (B-1), the second bucket counts transactions with response times greater than B-1 but less than or equal to B-2, and so on. The fifth bucket is unbounded, and it counts all transactions with response times greater than boundary 4.

The four bucket boundaries have default values of 1 second, 2 seconds, 5 seconds, and 10 seconds, respectively.

For comprehensive information about VTAM and router configuration issues and implementing specific TN3270 server scenarios, refer to the TN3270 Design and Implementation Guide.

To maintain a configuration file that exceeds 128 KB there are two alternatives:

• Store the configuration file compressed in NVRAM.

• Store the configuration file in Flash memory (either internal Flash or on a PCMCIA card).

For more information about maintaining configuration files, refer to the Cisco IOS Configuration Fundamentals Configuration Guide. For information about router hardware and memory, refer to the hardware configuration guide for your Cisco router series.

• Configuring CMPC support

• Configuring CSNA support

• Configuring Token Ring attachment to an FEP

For information about configuring CMPC or CSNA, see the "Configuring CSNA and CMPC" chapter in this publication.

Note If your host computer is customized for a character set other than U.S. English EBCDIC, you might need to code some VTAM configuration tables differently than indicated in the examples provided by Cisco. Some VTAM configurations include the number sign (#) and at symbol (@). In the U.S. English EBCDIC character set, these characters are stored as the hexadecimal values 7B and 7C, respectively. VTAM will look for those hexadecimal values when processing the configuration file. The characters used to enter these values are different in other EBCDIC National Language character sets. Table 19 lists the languages that have different characters for the 7B and 7C hexadecimal values and the corresponding symbols used to enter the characters. For example, the value for the LUSEED parameter in the PU definition called TN3270PU in Figure 299 has a value of TN3X1###. To properly code this value for LUSEED for the French National Language character set, the value should be TN3X1£££.

Table 19: International Character Sets for Hexadecimal Values

	Hexadecimal Value
	7B		7C
Language	Symbol	Description	Symbol	Description
German	#	Number sign	§	Section symbol
German (alternate)	Ä	A-dieresis	Ö	O-dieresis
Belgian	#	Number sign	à	a-grave
Brazilian	Õ	O-tilde	Ã	A-tilde
Danish/Norwegian	Æ	AE-ligature	Ø	O-slash
English (U.S./UK)	#	Number sign	@	At symbol
Finnish/Swedish	Ä	A-dieresis	Ö	O-dieresis
French	£	Pound sterling	à	a-grave
Greek	£	Pound sterling	§	Section symbol
Icelandic	#	Number sign	D	Uppercase eth
Italian	£	Pound sterling	§	Section symbol
Portuguese	Õ	O-tilde	Ã	A-tilde
Spanish	Ñ	N-tilde	@	At symbol
Turkish	Ö	O-dieresis	S	S-cedilla

router(config-if)# tn3270-server

The following prompt appears:

(cfg-tn3270)#

Note For the CIP, enter interface configuration mode from the virtual channel interface using port 2; For the CPA, enter interface configuration mode from the physical channel interface using port 0.

router(cfg-tn3270)# listen-point ip-address [tcp-port [number]]

The following prompt appears:

(tn3270-lpoint)#

• From the listen-point configuration mode, the following pu (listen-point) command creates a new direct PU:

router#(tn3270-lpoint)# pu pu-name idblk-idnum type adapno lsap [rmac rmac] [rsap rsap] [lu-seed lu-name-stem]

The pu (listen-point) command puts you in listen-point PU configuration mode and the following prompt appears:

(tn3270-lpoint-pu)#

• From listen-point configuration mode, the following pu dlur command creates a new PU for DLUR:

router#(tn3270-lpoint)# pu pu-name idblk-idnum dlur

The pu dlur command puts you in the listen-point PU configuration mode and the following prompt appears:

(tn3270-lpoint-pu)#

router(cfg-tn3270)# dlur fq-cpname fq-dlusname

The following prompt appears:

(tn3270-dlur)#

router(tn3270-dlur)# lsap type adapno [lsap]

The following prompt appears:

(tn3270-dlur-lsap)#

router(cfg-tn3270)# response-time group name [bucket boundaries t1 t2 t3 t4...][multiplier m]

The following prompt appears:

(tn3270-resp-time)#

router(cfg-tn3270)# pu pu-name idblk-idnum ip-address type adapno lsap [rmac rmac] [rsap rsap] [lu-seed lu-name-stem]

(tn3270-pu)#

• Parameters to identify the specific instance of the entity (for example, a PU name).

• Parameters to set operating options.

To return to a mode later in the configuration process, use the same configuration command but specify only the first set of identification parameters. The following examples show how to create, access, and remove different TN3270 entities in their associated configuration modes.

Working with a Listen-Point Direct PU

1. To create a listen-point direct PU entity called PU1 and enter listen-point PU configuration mode from listen-point configuration mode, use the pu (listen-point) command as shown in the following example:

router(tn3270-lpoint)# pu PU1 94201231 tok 1 10
 

2. To return later to the listen-point PU configuration mode for the PU1 entity, use the same pu (listen-point) command without the "94201231 tok 1 10" parameters from listen-point configuration mode:

router(tn3270-lpoint)# pu PU1
 

3. To remove the listen-point PU entity called PU1, use the same command with the no keyword:

router(tn3270-lpoint)# no pu PU1
 

Working with a Listen-Point DLUR PU

1. To create a listen-point DLUR PU entity called PU2 and enter listen-point PU configuration mode from listen-point configuration mode, use the pu dlur command as shown in the following example:

router(tn3270-lpoint)# pu PU2 017ABCDE dlur
 

2. To return later to the listen-point PU configuration mode for the PU2 entity, use the same pu dlur command without the "017ABCDE dlur" parameters from listen-point configuration mode:

router(tn3270-lpoint)# pu PU2
 

3. To remove the listen-point PU entity called PU2, use the same command with the no keyword:

router(tn3270-lpoint)# no pu PU2
 

Working with a DLUR Entity

The following example shows how to create, access, and remove a DLUR entity:

1. To create a DLUR entity with a control point name NETA.RTR1 and enter DLUR configuration mode from TN3270 configuration mode, use the dlur command as shown in the following example:

router(cfg-tn3270)# dlur NETA.RTR1 NETA.HOST
 

2. To return later to the DLUR configuration mode for the NETA.RTR1 entity, use the same dlur command without the "NETA.RTR1 and NETA.HOST" parameters from TN3270 configuration mode:

router(cfg-tn3270)# dlur
 

3. To remove the NETA.RTR1 DLUR entity, use the same dlur command with the no keyword:

router(cfg-tn3270)# no dlur
 

Working with a DLUR LSAP Entity

The following example shows how to create, access, and remove a DLUR LSAP entity:

1. To create a DLUR LSAP entity and enter DLUR SAP configuration mode from DLUR mode, type the following command:

router(tn3270-dlur)#lsap token-adapter 1 84
 

2. To return later to the DLUR SAP configuration mode on the same entity, use the same lsap command without the "84" parameter from TN3270 DLUR mode:

router(tn3270-dlur)#lsap token-adapter 1
 

3. To remove the DLUR LSAP entity, use the same identification parameters with the no keyword:

This section also describes the tasks to configure the TN3270 server in certain environments, and references the configuration options that are available there. Older TN3270 server configurations that are still supported but are replaced by newer methods of configuration are discussed in the legacy configuration topic.

Finally, this section includes a basic procedure for verifying the TN3270 server configuration.

This section includes the following topics:

Note You cannot configure the siftdown commands shown in Table 20 while in DLUR, DLUR SAP, or response-time configuration modes for the TN3270 server.

The siftdown commands apply to the corresponding PUs, according to the configuration mode in which they are entered:

• TN3270 server configuration---The siftdown command at this level applies to all PUs supported by the TN3270 server.

• Listen-point configuration---The siftdown command at this level applies to all PUs defined at the listen point.

• Listen-point PU configuration---The siftdown command at this level applies to only the specified PU.

• PU configuration---The siftdown command at this level applies only to the specified PU.

This section describes how to configure the following options for the TN3270 server:

A leftover LU is an unactivated LU from a pool of dynamic LUs, which are defined in the switched major node in VTAM using the LU-SEED parameter and the LUGROUP parameter. A leftover LU is defined as an LU where all of the following conditions are true:

• The SSCP did not send an ACTLU during PU start-up.

• The PU controlling the LU is capable of carrying product set ID (PSID) vectors on NMVT messages, thus allowing DDDLU operation for that LU.

The default behavior is to permit a generic pool of LUs in the TN3270 server and allow leftover LUs to be used for dynamic connections. You might deny the use of the generic pool for security reasons.

To configure a generic pool of LUs for the TN3270 server, use the following command in TN3270 server, listen-point, listen-point PU, PU, or DLUR PU configuration modes:

Command

Purpose

Router#generic-pool {permit | deny}

(Optional) Specifies whether leftover LUs can be used from a generic LU pool. The available options for this command are: permit---Specifies that leftover LUs can be used by clients that request a generic session. Inactive LUs are immediately available for dynamic connections. This is the default. deny---Specifies that the TN3270 server does not allow any further dynamic connections of any LUs on the PU. That is, only static LUs are supported.

The generic-pool command takes effect immediately for all upcoming connections, but existing sessions are unaffected. Once the existing sessions are terminated, then future connections will abide by the latest generic pool configuration for that PU. Use the no form of this command to selectively remove the permit or deny condition of generic pool use for the corresponding PU and return to the previously configured siftdown value applicable to the PU, or to the default value.

To prevent an LU session from being disconnected due to inactivity, specify an idle time value of zero seconds. Note that TIMING-MARKS generated by the TN3270 server keepalive function are not considered "activity" on the client connection.

NoteThere are two TN3270 server options that can affect when a session is disconnected---idle time and keepalive. These two options operate independently of each other and both can be used to clean up partially disconnected sessions. Whichever option first detects that a session is eligible for disconnect immediately causes the TN3270 server to disconnect that session. If you are specifying both the idle time and keepalive options, then you might consider how the values for these options determine when client sessions are disconnected to achieve the response that you want.

To configure the allowable amount of idle time before the TN3270 server disconnects an LU, use the following command in TN3270 server, listen-point, listen-point PU, PU, or DLUR PU configuration modes:

Command	Purpose
Router#idle-time seconds	(Optional) Specifies the number of seconds of inactivity before the TN3270 server disconnects an LU.

The default behavior in TN3270 server configuration mode is that the session is never disconnected (or, a value of 0). The default value in other configuration modes is the value currently configured for that PU in a previously supported mode. Use the no form of this command to cancel the idle time period and return to the default for the corresponding PU.

The TN3270 server allows you to specify different IP precedence values for screen and printer clients because the communication requirements for each type of client is different. Screen clients are characterized by interactive communication which normally demands a higher priority of data transfer than printers. Printers are characterized by bulk data transfer where priority of the data transmission is not as high.

To configure the traffic priority for screen and printer clients in the TN3270 server, use the following command in TN3270 server, listen-point, PU, or DLUR PU configuration modes:

Command	Purpose
Router#ip precedence {screen | printer} value	(Optional) Specifies the precedence level (from 0 to 7) for IP traffic in the TN3270 server. The default value is 0.

Use the no form of this command to remove the screen or printer precedence value for the corresponding PU and return to the previously configured siftdown value applicable to the PU, or to the default value. However, you can enter new or different values for IP precedence without first using the no form of the command.

The TN3270 server allows you to specify different IP TOS values for screen and printer clients because the communication requirements for each type of client is different. Screen clients are characterized by interactive communication which normally demands a higher priority of data transfer than printers. Printers are characterized by bulk data transfer where priority of the data transmission is not as high.

To configure the level of service for screen and printer clients in the TN3270 server, use the following command in TN3270 server, listen-point, PU, or DLUR PU configuration modes:

Command	Purpose
Router#ip tos {screen | printer} value	(Optional) Specifies a type of service level (from 0 to 15) for IP traffic in the TN3270 server.

Use the no form of this command to remove the screen or printer TOS value for the corresponding PU and return to the previously configured siftdown value applicable to the PU, or to the default value. However, you can enter new or different values for IP TOS without first using the no form of the command.

When you configure the keepalive command to send Telnet nop commands, no response is required by the client. If you specify only the keepalive interval, then the TN3270 server sends timing marks.

The default behavior of the TN3270 server is to send timing marks every 30 minutes if there is no other traffic flowing between the TN3270 client and server. The TN3270 server disconnects a session if the client does not respond within 30 seconds.

The keepalive command affects currently active and future TN3270 sessions. For example, reducing the keepalive interval for timing marks to a smaller nonzero value causes an immediate burst of DOTIMING-MARKS on those sessions that have been inactive for a period of time greater than the new, smaller value.

NoteThere are two TN3270 server options that can affect when a session is disconnected---idle time and keepalive. These two options operate independently of each other and both can be used to clean up partially disconnected sessions. Whichever option first detects that a session is eligible for disconnect immediately causes the TN3270 server to disconnect that session. If you are specifying both the idle time and keepalive options, then you might consider how the values for these options determine when client sessions are disconnected to achieve the response that you want.

To configure the keepalive options for the TN3270 server, use the following command in TN3270 server, listen-point, listen-point PU, PU, or DLUR PU configuration modes:

Command

Purpose

Router#keepalive seconds [send {nop | timing-mark [max-response-time]}]

(Optional) Specifies the number of seconds (from 0 to 65535) of inactivity to elapse before the TN3270 server transmits a DOTIMING-MARK or Telnet nop to the TN3270 client. A value of 0 means that no keepalive signals are sent. The default interval is 1800 seconds (30 minutes). The following options are available: send nop---Sends the Telnet command for no operation to the TN3270 client to verify the physical connection. send timing-mark [max-response-time]---Sends timing marks to verify the status of the client session and specifies the number of seconds (from 0 to 32767) within which the TN3270 server expects a response. The default maximum response time is 30 seconds if the keepalive interval is greater than or equal to 30 seconds. If the value of the keepalive interval is less than 30seconds, then the default max-response-time is the value of the interval. The value of max-response-time should be less than or equal to the interval.

Use the no form of the command to cancel the current keepalive period and type and return to the previously configured siftdown value applicable to the PU, or to the default value.

Command	Purpose
Router#client [printer] ip ip-address [mask] lu first-locaddr [last-locaddr]	(Optional) Allocates a specific LU or range of LUs to a client located at the IP address or subnet.

Command	Purpose
Router(tn3270-lpoint)#client ip ip-address [mask] pool poolname	(Optional) Nails a client located at the IP address or subnet to a pool.

To allocate LUs to a pool use the following command in listen-point PU configuration mode:

Command	Purpose
Router(tn3270-lpoint-pu)#allocate lu lu-address pool poolname clusters count	(Optional) Assigns LUs to the pool beginning with the LOCADDR specified by lu-address for a total of count LUs.

The default behavior of the TN3270 server is to never delete LUs upon disconnect. This option is useful when you only have screen LUs and they all use the same screen size.

To configure the LU deletion options for the TN3270 server, use the following command in TN3270 server, listen-point, listen-point PU, PU, or DLUR PU configuration modes:

Command

Purpose

Router#lu deletion {always | normal | non-generic | never}

(Optional) Specifies when the TN3270 server sends a REPLY-PSID poweroff request for an LU upon disconnect. The following options are available: always---Specifies deletion of all dynamic LUs upon disconnect. normal---Specifies deletion of only screen LUs upon disconnect. non-generic---Specifies deletion of specified LUs. (Available when VTAM supports deletion of specifically-named LUs. Not available as of VTAM version 4.4.1.) never---Specifies that LUs are never deleted upon disconnect. This is the default.

Use the no form of the command to remove LU deletion from the current configuration scope and return to the previously configured siftdown value applicable to the PU, or to the default value.

With some applications (such as CICS), VTAM security problems can arise from an UNBIND request. In some cases the application might reestablish a previous user's session with a new user, who is now assigned to the same freed LU. To prevent this you can configure the TN3270 server to send a TERMSELF RU.

Use the termself keyword of the lu termination command when you want to be sure that the application terminates the session when the LU disconnects.

To configure the LU termination options for the TN3270 server, use the following command in TN3270 server, listen-point, listen-point PU, PU, or DLUR PU configuration modes:

Command	Purpose
Router#lu termination {termself | unbind}	(Optional) Specifies the type of RU sent by the TN3270 server when a client turns off the device or disconnects. The following options are available: termself---Orders termination of all sessions and session requests associated with an LU upon disconnect. unbind---Requests termination of the session by the application upon LU disconnect. This is the default.

Use the no form of the command to remove LU termination from the current configuration scope and return to the previously configured siftdown value applicable to the PU, or to the default value.

Each control block uses about 1 KB of memory, with a possible 2 KB per LU additionally required for data during session activity. The TN3270 server attempts to allocate one LU control block for each LU activated by the host. For DDDLU, the control block is allocated when the client requests the LU, in anticipation of an ACTLU from the SSCP host.

By limiting the number of LU control blocks allocated, you can limit how much memory is used for the TN3270 server and be sure that memory is available to support other CMCC functions.

To configure the maximum number of LUs allowed for the TN3270 server, use the following command in TN3270 server configuration mode:

Command	Purpose
Router(cfg-tn3270)#maximum-lus number	(Optional) Specifies the maximum number (between 0 and 32000) of LU control blocks allowed for the TN3270 server. The default is 2100.

If you do not configure the maximum number of LU sessions, the default configuration specifies no limit on the number of concurrent sessions from one client IP address.

To configure the maximum number of LU sessions allowed for a TN3270 client, use the following command in TN3270 server configuration mode:

Command	Purpose
Router(cfg-tn3270)#client [ip [ip-mask]] lu maximum number	(Optional) Specifies the maximum number of LU sessions (between 0 and 65535) for each client IP address or IP subnet address.

There are two ways that you can configure the TCP port:

• Using TN3270 server or PU configuration modes for the PU. This is the only method supported in legacy configurations, prior to CiscoIOS Release 12.0(5)T.

• In Cisco IOS Release 12.0(5)T and later, the TCP port can alternatively be configured in a listen point for the PU.

Legacy Configuration

To configure the TCP port in legacy configurations that do not implement a listen point, use the following command in TN3270 server, PU, or DLUR PU configuration modes:

Command	Purpose
Router(cfg-tn3270)#tcp-port number	(Optional) Specifies the TCP port (between 0 and 65534) to be used for the PU. The default TCP port number is 23.

Use the no form of the command to remove the TCP port from the current configuration scope and return to the previously configured siftdown value applicable to the PU, or to the default value.

Command	Purpose
Router(cfg-tn3270)#listen-point ip-address [tcp-port [number]]	Specifies the IP address and TCP port number to create a listen point. The default TCP port number is 23. This command changes the configuration mode from TN3270 to listen-point.

The default behavior of the TN3270 server is to transmit timing marks only for the keepalive function. If you configure the TN3270 server to send timing marks to achieve an end-to-end response protocol, then a WILL TIMING-MARK is sent by the TN3270 server when any of the following conditions are true:

• The host application requests a pacing response.

• The host application requests a definite response (DR), and either the client is not using TN3270E, or the request is not Begin Chain.

The use of timing marks can degrade performance. Some clients do not support timing marks used in this way. Therefore you should only configure timing marks when both of the following conditions are true:

• All clients support this timing mark usage.

• The application benefits from end-to-end acknowledgment.

To configure the timing marks option for the TN3270 server, use the following command in TN3270 server configuration mode:

Command	Purpose
Router(cfg-tn3270)#timing-mark	(Optional) Specifies that the TN3270 server sends a WILL TIMING-MARK in response to an application request for a pacing or definite response.

The default behavior in TN3270 server configuration mode is to disconnect the client session upon receipt of an UNBIND. In other configuration modes the default behavior is the currently configured value in the configuration mode applicable to the PU.

To configure the unbind action for the TN3270 server, use the following command in TN3270 server, listen-point, listen-point PU, PU, or DLUR PU configuration modes:

Command	Purpose
Router(cfg-tn3270)#unbind-action {keep | disconnect}	(Optional) Specifies whether the TN3270 session disconnects when an UNBIND request is received.

Use the no form of the command to remove the unbind action from the current configuration scope and return to the previously configured siftdown value applicable to the PU, or to the default value.

When configured, the pool becomes one of the several criteria used by the TN3270 server to assign an LU to a client. When a client requests a connection, the TN3270 server determines the authorized capabilities of the client. For example, the TN3270 server attempts to determine whether LU nailing definitions exist for the client.

Client preferences are taken into consideration. Examples of client preferences are:

• Device name on CONNECT request (TN3270E)

• LU name on TERMINAL-TYPE command (RFC 1576)

• Model type

When the client criteria is processed, the TN3270 server assigns the first available LU in the group to the client. If an appropriate LU is not found, the TN3270 connection is closed.

	Command	Purpose
Step1	Router(config)#interface channel slot/port	Selects the interface on which to configure the TN3270 server and enters interface configuration mode. The port value differs by the type of CMCC adapter: CIP---Port value corresponds to the virtual interface, which is port 2. CPA---Port value corresponds to port 0.
Step2	Router(config-if)#tn3270-server	Specifies a TN3270 server on the internal LAN interface and enters TN3270 server configuration mode.
Step3	Router(cfg-tn3270)#pool poolname [cluster layout [layout-spec-string]]	Defines clusters of LUs and allocates LOCADDRs.
Step4	Router(cfg-tn3270)#generic-pool {permit | deny}	(Optional) Selects whether "leftover" LUs can be used from a generic LU pool.
Step5	Router(cfg-tn3270)#idle-time seconds	(Optional) Specifies the idle time for server disconnect.
Step6	Router(cfg-tn3270)#ip precedence {screen | printer} value	(Optional) Specifies the precedence level for IP traffic in the TN3270 server.
Step7	Router(cfg-tn3270)#ip tos {screen | printer} value	(Optional) Specifies the TOS level for IP traffic in the TN3270 server.
Step8	Router(cfg-tn3270)#keepalive seconds [send {nop | timing-mark [max-response-time]}]	(Optional) Specifies the following keepalive parameters: Number of seconds of inactivity to elapse before the TN3270 server transmits a DO TIMING-MARK or Telnet nop to the TN3270 client. Maximum time within which the TN3270 server expects a response to the DO TIMING-MARK from the TN3270 client before the server disconnects.
Step9	Router(cfg-tn3270)#lu deletion {always | normal | non-generic | never}	(Optional) Specifies whether the TN3270 server sends a REPLY-PSID poweroff request to VTAM to delete the corresponding LU when a client disconnects.
Step10	Router(cfg-tn3270)#lu termination {termself | unbind}	(Optional) Specifies the type of termination request that is sent by the TN3270 server when a client turns off or disconnects a device.
Step11	Router(cfg-tn3270)#maximum-lus number	(Optional) Specifies the maximum number (between 0 and 32000) of LU control blocks allowed for the TN3270 server. The default is 2100.
Step12	Router(cfg-tn3270)#client [ip [ip-mask]] lu maximum number	(Optional) Specifies the maximum number (between 0 and 65535) of LU sessions allowed for a client at an IP address or IP subnet address.
Step13	Router(cfg-tn3270)#timing-mark	(Optional) Specifies that the TN3270 server sends a WILL TIMING-MARK in response to an application request for a pacing or definite response.
Step14	Router(cfg-tn3270)#unbind-action {keep | disconnect}	(Optional) Specifies whether the TN3270 session will disconnect when an UNBIND request is received.

	Command	Purpose
Step1	Router(cfg-tn3270)#dlur fq-cpname fq-dlusname	Creates a DLUR function in the TN3270 server and enters DLUR configuration mode.
Step2	Router(tn3270-dlur)#dlus-backup dlusname2	(Optional) Specifies the fallback choice for the DLUR DLUS.
Step3	Router(tn3270-dlur)#preferred-nnserver NNserver	(Optional) Specifies the preferred network node (NN) server.

	Command	Purpose
Step1	Router(tn3270-dlur)#lsap type adapno [lsap]	Creates a SAP function under DLUR and enters DLUR SAP configuration mode.
Step2	Router(tn3270-dlur-lsap)#vrn vrn-name	(Optional) Identifies an APPN virtual routing node (VRN).
Step3	Router(tn3270-dlur-lsap)#link name [rmac rmac] [rsap rsap]	(Optional) Creates 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.

When you use the listen-point command, you enter listen-point configuration mode and can use all other commands in this task list. Values that you enter for siftdown commands in listen-point configuration mode will override values that you previously entered in TN3270 server configuration mode.

	Command	Purpose
Step1	Router(cfg-tn3270)#listen-point ip-address [tcp-port [number]]	Specifies the IP address and TCP port number to create a listen point. The default TCP port number is 23. This command changes the configuration mode from TN3270 to listen-point.
Step2	Router(tn3270-lpoint)#client ip ip-address [mask] pool poolname	Nails a client located at the IP address or subnet to a pool.
Step3	Router(tn3270-lpoint)#generic-pool {permit | deny}	(Optional) Selects whether "leftover" LUs can be used from a generic LU pool.
Step4	Router(tn3270-lpoint)#idle-time seconds	(Optional) Specifies the idle time for server disconnect.
Step5	Router(tn3270-lpoint)#ip precedence {screen | printer} value	(Optional) Specifies the precedence level for IP traffic in the TN3270 server.
Step6	Router(tn3270-lpoint)#ip tos {screen | printer} value	(Optional) Specifies the TOS level for IP traffic in the TN3270 server.
Step7	Router(tn3270-lpoint)#keepalive seconds [send {nop | timing-mark [max-response-time]}]	(Optional) Specifies the following keepalive parameters: Number of seconds of inactivity to elapse before the TN3270 server transmits a DO TIMING-MARK or Telnet nop to the TN3270 client. Maximum time within which the TN3270 server expects a response to the DO TIMING-MARK from the TN3270 client before the server disconnects.
Step8	Router(tn3270-lpoint)#lu deletion {always | normal | non-generic | never}	(Optional) Specifies whether the TN3270 server sends a REPLY-PSID poweroff request to VTAM to delete the corresponding LU when a client disconnects.
Step9	Router(tn3270-lpoint)#lu termination {termself | unbind}	(Optional) Specifies the type of termination request that is sent by the TN3270 server when a client turns off or disconnects a device.
Step10	Router(tn3270-lpoint)#unbind-action {keep | disconnect}	(Optional) Specifies whether the TN3270 session will disconnect when an UNBIND request is received.

When you use the pu command, you enter listen-point PU configuration mode and can use all other commands in this task list. Values that you enter for siftdown commands in listen-point PU configuration mode will override values that you previously entered in listen-point or TN3270 server configuration mode.

	Command	Purpose
Step1	Router(tn3270-lpoint)#pu pu-name idblk-idnum dlur	Creates a DLUR PU. This command changes the configuration mode from listen-point to listen-point PU.
Step2	Router(tn3270-lpoint-pu)#allocate lu lu-address pool poolname clusters count	Assigns LUs to the pool beginning with the LOCADDR specified by lu-address for a total of count LUs.
Step3	Router(tn3270-lpoint-pu)#generic-pool {permit | deny}	(Optional) Selects whether "leftover" LUs can be used from a generic LU pool.
Step4	Router(tn3270-lpoint-pu)#idle-time seconds	(Optional) Specifies the idle time for server disconnect.
Step5	Router(tn3270-lpoint-pu)#keepalive seconds [send {nop | timing-mark [max-response-time]}]	(Optional) Specifies the following keepalive parameters: Number of seconds of inactivity to elapse before the TN3270 server transmits a DO TIMING-MARK or Telnet nop to the TN3270 client. Maximum time within which the TN3270 server expects a response to the DO TIMING-MARK from the TN3270 client before the server disconnects.
Step6	Router(tn3270-lpoint-pu)#lu deletion {always | normal | non-generic | never}	(Optional) Specifies whether the TN3270 server sends a REPLY-PSID poweroff request to VTAM to delete the corresponding LU when a client disconnects.
Step7	Router(tn3270-lpoint-pu)#lu termination {termself | unbind}	(Optional) Specifies the type of termination request that is sent by the TN3270 server when a client turns off or disconnects a device.
Step8	Router(tn3270-lpoint-pu)#unbind-action {keep | disconnect}	(Optional) Specifies whether the TN3270 session will disconnect when an UNBIND request is received.

	Command	Purpose
Step1	Router(config)#interface channel slot/port	Selects the interface on which to configure the TN3270 server and enters interface configuration mode. The port value differs by the type of CMCC adapter: CIP---port value corresponds to the virtual interface, which is port 2. CPA---port value corresponds to port 0.
Step2	Router(config-if)#tn3270-server	Specifies a TN3270 server on the internal LAN interface and enters TN3270 server configuration mode.
Step3	Router(cfg-tn3270)#pool poolname [cluster layout [layout-spec-string]]	Defines clusters of LUs and allocates LOCADDRs.
Step4	Router(cfg-tn3270)#idle-time seconds	(Optional) Specifies the idle time for server disconnect.
Step5	Router(cfg-tn3270)#keepalive seconds [send {nop | timing-mark [max-response-time]}]	(Optional) Specifies the following keepalive parameters: Number of seconds of inactivity to elapse before the TN3270 server transmits a DO TIMING-MARK or Telnet nop to the TN3270 client. Maximum time within which the TN3270 server expects a response to the DO TIMING-MARK from the TN3270 client before the server disconnects.
Step6	Router(cfg-tn3270)#ip precedence {screen | printer} value	(Optional) Specifies the precedence level for IP traffic in the TN3270 server.
Step7	Router(cfg-tn3270)#ip tos {screen | printer} value	(Optional) Specifies the TOS level for IP traffic in the TN3270 server.
Step8	Router(cfg-tn3270)#unbind-action {keep | disconnect}	(Optional) Specifies whether the TN3270 session will disconnect when an UNBIND request is received.
Step9	Router(cfg-tn3270)#generic-pool {permit | deny}	(Optional) Selects whether "leftover" LUs can be used from a generic LU pool.
Step10	Router(cfg-tn3270)#lu deletion {always | normal | non-generic | never}	(Optional) Specifies whether the TN3270 server sends a REPLY-PSID poweroff request to VTAM to delete the corresponding LU when a client disconnects.
Step11	Router(cfg-tn3270)#lu termination {termself | unbind}	(Optional) Specifies the type of termination request that is sent by the TN3270 server when a client turns off or disconnects a device.

When you use the listen-point command, you enter listen-point configuration mode and can use all other commands in this task list. Values that you enter for siftdown commands in listen-point configuration mode will override values that you previously entered in TN3270 server configuration mode.

	Command	Purpose
Step1	Router(cfg-tn3270)#listen-point ip-address [tcp-port [number]]	Specifies the IP address and TCP port number to create a listen point. The default TCP port number is 23. This command changes the configuration mode from TN3270 to listen-point.
Step2	Router(tn3270-lpoint)#client ip ip-address [mask] pool poolname	Nails a client located at the IP address or subnet to a pool.
Step3	Router(tn3270-lpoint)#idle-time seconds	(Optional) Specifies the idle time for server disconnect.
Step4	Router(tn3270-lpoint)#keepalive seconds [send {nop | timing-mark [max-response-time]}]	(Optional) Specifies the following keepalive parameters: Number of seconds of inactivity to elapse before the TN3270 server transmits a DO TIMING-MARK or Telnet nop to the TN3270 client. Maximum time within which the TN3270 server expects a response to the DO TIMING-MARK from the TN3270 client before the server disconnects.
Step5	Router(tn3270-lpoint)#ip precedence {screen | printer} value	(Optional) Specifies the precedence level for IP traffic in the TN3270 server.
Step6	Router(tn3270-lpoint)#ip tos {screen | printer} value	(Optional) Specifies the TOS level for IP traffic in the TN3270 server.
Step7	Router(tn3270-lpoint)#unbind-action {keep | disconnect}	(Optional) Specifies whether the TN3270 session will disconnect when an UNBIND request is received.
Step8	Router(tn3270-lpoint)#generic-pool {permit | deny}	(Optional) Selects whether "leftover" LUs can be used from a generic LU pool.
Step9	Router(tn3270-lpoint)#lu deletion {always | normal | non-generic | never}	(Optional) Specifies whether the TN3270 server sends a REPLY-PSID poweroff request to VTAM to delete the corresponding LU when a client disconnects.
Step10	Router(tn3270-lpoint)#lu termination {termself | unbind}	(Optional) Specifies the type of termination request that is sent by the TN3270 server when a client turns off or disconnects a device.

When you use the pu command, you enter listen-point PU configuration mode and can use all other commands in this task list. Values that you enter for siftdown commands in listen-point PU configuration mode will override values that you previously entered in listen-point or TN3270 server configuration mode.

	Command	Purpose
Step1	Router(tn3270-lpoint)#pu pu-name idblk-idnum type adapter-number lsap [rmac rmac] [rsap rsap] [lu-seed lu-name-stem]	Creates a direct PU. This command changes the configuration mode from listen-point to listen-point PU.
Step2	Router(tn3270-lpoint-pu)#allocate lu lu-address pool poolname clusters count	Assigns LUs to the pool beginning with the LOCADDR specified by lu-address for a total of count LUs.
Step3	Router(tn3270-lpoint-pu)#idle-time seconds	(Optional) Specifies the idle time for server disconnect.
Step4	Router(tn3270-lpoint-pu)#keepalive seconds [send {nop | timing-mark [max-response-time]}]	(Optional) Specifies the following keepalive parameters: Number of seconds of inactivity to elapse before the TN3270 server transmits a DO TIMING-MARK or Telnet nop to the TN3270 client. Maximum time within which the TN3270 server expects a response to the DO TIMING-MARK from the TN3270 client before the server disconnects.
Step5	Router(tn3270-lpoint-pu)#unbind-action {keep | disconnect}	(Optional) Specifies whether the TN3270 session will disconnect when an UNBIND request is received.
Step6	Router(tn3270-lpoint-pu)#generic-pool {permit | deny}	(Optional) Selects whether "leftover" LUs can be used from a generic LU pool.
Step7	Router(tn3270-lpoint-pu)#lu deletion {always | normal | non-generic | never}	(Optional) Specifies whether the TN3270 server sends a REPLY-PSID poweroff request to VTAM to delete the corresponding LU when a client disconnects.
Step8	Router(tn3270-lpoint-pu)#lu termination {termself | unbind}	(Optional) Specifies the type of termination request that is sent by the TN3270 server when a client turns off his device or disconnects.

Nailing Clients to Pools

For example, the following configuration statements are in error because LU 5 is allocated to both the pool and to an individual client at IP address 10.20.30.40:

tn3270-server
 pool MYPOOL cluster layout 4s1p
 pu PU1 12345678 tok 0 10
 allocate lu 5 pool MYPOOL clusters 2
 client ip 10.20.30.40 lu 5
 

The following example shows a valid configuration where a client at IP address 10.20.30.40 is nailed to the pool named EXAMPLE, which is allocated LOCADDRs 1 through 10, and an individual client at IP address 10.20.30.50 that is nailed only to LU 150:

For detailed examples of configuration verification procedures for specific TN3270 server scenarios, see the Cisco TN3270 Design and Implementation Guide.

To verify a TN3270 server configuration that uses LU pooling, perform the following steps:

router#show run
Building configuration...
 
interface Channel6/1
 no ip address
 no keepalive
 csna E160 40
!
interface Channel6/2
 ip address 172.18.4.17 255.255.255.248
 no keepalive
 lan TokenRing 15
  source-bridge 15 1 500
  adapter 15 4000.b0ca.0015
 lan TokenRing 16
  source-bridge 16 1 500
  adapter 16 4000.b0ca.0016
 tn3270-server
  pool PCPOOL   cluster layout 4s1p
  pool SIMPLE   cluster layout 1a
  pool UNIXPOOL cluster layout 49s1p
  dlur NETA.SHEK NETA.MVSD
   lsap token-adapter 15 04
    link SHE1     rmac 4000.b0ca.0016
  listen-point 172.18.4.18 tcp-port 23
   pu PU1      91903315 dlur
    allocate lu 1 pool PCPOOL   clusters 10
    allocate lu 51 pool UNIXPOOL clusters 2
    allocate lu 200 pool SIMPLE   clusters 50
  listen-point 172.18.4.19 tcp-port 2023
   pu PU2      91913315 token-adapter 16 08
    allocate lu 1 pool UNIXPOOL clusters 2
    allocate lu 101 pool SIMPLE   clusters 100
    allocate lu 201 pool PCPOOL   clusters 10
 

Step 2 To display information about the client LUs associated with a specific PU including the cluster layout and pool name, enter the show extended channel tn3270-server pu command:

	Command	Purpose
Step1	Router(tn3270-resp-time)#response-time group name [bucket boundaries t1 t2 t3 t4] [multiplier m]	Configures the client subnet response-time group.
Step2	Router(tn3270-resp-time)#client ip ip-address [ip-mask]	Specifies the IP address of the subnet being added to this client group.

To display a complete list of client subnet groups and their response-time collection control parameters, use the following form of the command:

Router#show extended channel 3/2 tn3270-server response-time subnet
group SUBNETGROUP1
  subnet 10.10.10.0 255.255.255.192
  aggregate NO excludeip NO dynamic definite response NO
  sample period multiplier 30
  bucket boundaries 10 20 50 100
group SUBNETGROUP2
  subnet 10.10.10.128 255.255.255.192
  subnet 10.10.10.192 255.255.255.192
  aggregate NO exclude ip NO dynamic definite response NO
  sample period multiplier 40
  bucket boundaries 20 30 60 120
group CLIENT SUBNET OTHER
  aggregate NO exclude ip NO dynamic definite response NO
  sample period multiplier 30
  bucket boundaries 10 20 50 100
 

To display the response-time collection parameters for a specific subnet, along with a list of the client members and their response-time statistics, use the following form of the command:

Router#show extended channel 3/2 tn3270-server response-time subnet
10.10.10.0 255.255.255.192 detail
 
group SUBNETGROUP1
  subnet 10.10.10.0 255.255.255.192
  aggregate NO excludeip NO dynamic definite response NO
  sample period multiplier 30
  bucket boundaries 10 20 50 100
  client 10.10.10.129:23
    buckets 5 8 11 9 4
    average total response time 33 average IP response time 24
    number of transactions 37
  client 10.10.10.130:23
    buckets 6 9 10 10 2
    average total response time 32 average IP response time 25
    number of transactions 37
  client 10.10.10.131:23
    buckets 11 14 10 8 7
    average total response time 27 average IP response time 19
    number of transactions 50

• CIP---port value corresponds to the virtual interface, which is port 2.

• CPA---port value corresponds to port 0.

Command	Purpose
Router#show extended channel slot/port tn3270-server	Displays the current server configuration parameters and the status of the PUs defined in each server.
Router#show extended channel slot/port tn3270-server client-ip-address ip-address [disconnected | in-session | pending]	Displays information about all clients at a specific IP address.
Router#show extended channel slot/port tn3270-server dlur	Displays information about the SNA session switch.
Router#show extended channel slot/port tn3270-server dlurlink name	Displays information about the DLUR components.
Router#show extended channel slot/port tn3270-server nailed-ip ip-address	Displays mappings between a nailed client IP address and nailed LUs.
Router#show extended channel slot/virtual channel tn3270-server pu pu-name [cluster]	Displays information about the client LUs associated with a specified PU including the cluster layout and pool name.
Router#show extended channel tn3270-server pu pu-name lu lu-number [history]	Displays the status of the LU.
Router#show extended channel slot/port tn3270-server response-time application [appl-name [detail]]	Displays information about each client group application for the specified VTAM appl name. List each member of the client group with its individual response-time statistics.
Router#show extended channel slot/port tn3270-server response-time global	Displays information about the global client groups.
Router#show extended channel slot/port tn3270-server response-time link [link-name]	Displays information about the specified per-host-link client group.
Router#show extended channel slot/port tn3270-server response-time listen-point	Displays information about listen-point type client groups.
Router#show extended channel slot/port tn3270-server response-time subnet [ip-address ip-mask [detail]]	Displays information about the specified client group.

There are several advantages of converting a dynamic link to a static link:

• Supports removing a DLUR link without having to shut down the entire DLUR subsystem.

• In Network Node server configurations, having two or three static links defined allows you to provide adequate redundancy. You might want to convert a dynamic link to a static link to provide this benefit.

• Static links allow better control from the router end to show and control them. Dynamic links cannot be specifically shown or controlled by the router. The links appear in show command output, but with locally assigned names such as @DLURnn which make them difficult to identify.

For example, use the following link (TN3270) command to convert the existing dynamic link named HOST at RMAC 4000.0000.0001 and RSAP 4 to a static link:

link HOST rmap 4000.0000.0001 rsap 4

	Command	Purpose
Step1	Router(tn3270-dlur-lsap)#link name [rmac rmac] [rsap rsap]	Creates named links to hosts, or if this is an existing dynamic link, converts the dynamic link to a static link.
Step2	Router(tn3270-dlur-lsap)#no link name	Removes the link definition.

For TN3270 server configurations, you can use the shutdown command in the following command modes:

• TN3270 server configuration mode---Shuts down the entire TN3270 server function.

• PU configuration mode---Shuts down an individual PU entity within the TN3270 server.

• DLUR configuration mode---Shuts down the whole DLUR subsystem within the TN3270 server.

• DLUR PU configuration mode---Shuts down an individual PU within the SNA session switch configuration in the TN3270 server.

• DLUR SAP configuration mode---Shuts down the local SAP and its associated links within the SNA session switch configuration.

• Listen-point configuration mode---Shuts down a listen point and all of its associated configuration entities.

• Listen-point PU configuration mode---Shuts down an individual PU within the listen point configuration.

To shutdown the TN3270 server or a specific entity within the TN3270 server configuration, use the following command in the appropriate configuration mode:

Command	Purpose
Router#shutdown	Shuts down the entities corresponding to the configuration level in which the shutdown command is entered.

tn3270-server
pu PU1 94223456 10.10.10.1 tok 1 08
tcp-port 40
keepalive 10

The following example shows the same router with a later TN3270 server configuration that replaces the existing configuration and uses the listen-point command to accomplish LU pooling. The listen-point command was first introduced in Cisco IOS Release 11.2(18)BC.

tn3270-server
listen-point 10.10.10.1 tcp-port 40
pu PU1 94223456 tok 1 08
keepalive 10

NoteIn the new configuration, the IP address is not configured in the PU. Instead, the IP address is configured as a listen point and the PU is configured within the scope of the listen point. The tcp-port command is not configured within the scope of the PU, instead it is specified with the listen-point command.

tn3270-server
pu PU1 94201231 10.10.10.2 tok 1 10
pu PU2 94201232 10.10.10.3 tok 1 12
pu PU3 94201234 10.10.10.3 tok 1 14
pu PU4 94201235 10.10.10.4 tok 1 16
tcp-port 40
pu PU5 94201236 10.10.10.4 tok 2 08
 

The following example shows the same router replaced with a later TN3270 server configuration that uses the listen-point command introduced in Cisco IOS Release 11.2(18)BC:

tn3270-server 
listen-point 10.10.10.2 
pu PU1 94201231  tok 1 10
listen-point 10.10.10.3
pu PU2 94201232  tok 1 12
pu PU3 94201234  tok 1 14
listen-point 10.10.10.4
pu PU5 94201236  tok 2 08
listen-point 10.10.10.4 tcp-port 40
pu PU4 94201235  tok 1 16

In this example, PU2 and PU3 are grouped into one listen point because they have the same IP address. Note that even though PU4's IP address is identical to PU5's IP address, they are not configured within the same listen point because the listen point indicates a unique IP address and TCP port pair. If you do not specify the TCP port, the default port value is 23.

tn3270-server
dlur NETA.RTR1 NETA.HOST
dlus-backup NETA.HOST 
lsap token-adapter 15 08
link MVS2TN   rmac 4000.b0ca.0016
pu PU1 017ABCDE 10.10.10.6

The following example shows the same router replaced with a later TN3270 server configuration that uses the new listen-point command introduced in Cisco IOS Release 11.2(18)BC:

tn3270-server
dlur NETA.RTR1 NETA.HOST
dlus-backup NETA.HOST 
lsap token-adapter 15 08
link MVS2TN   rmac 4000.b0ca.0016
listen-point 10.10.10.6
pu PU1 017ABCDE dlur

In this example, the PU is not configured within the scope of DLUR. Instead the PU is configured within the listen-point scope. The keyword dlur differentiates the listen-point direct PU from the listen-point DLUR PU. Note that the DLUR configuration must be completed before PU1 is configured.

Any siftdown commands configured within the scope of listen point are automatically inherited by the PUs that are configured within the scope of that listen point. To override the siftdown configurations, you can explicitly configure the siftdown configuration commands within the scope of the listen-point PU.

To understand how LUs are allocated for clients that are nailed to pools in the TN3270 server, consider the router configuration for PU2 on the following pages, and assume that cluster 1 for PCPOOL has no LUs currently assigned to clients.

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
no keepalive
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 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 listen-points and DLUR PUs
router(cfg-tn3270)#listen-point 10.10.20.1
router(tn3270-lpoint)#pu pu0 05d99001 dlur
router(tn3270-lpoint-pu)#exit
router(tn3270-lpoint)#pu pu1 05d99002 dlur
router(tn3270-lpoint-pu)#exit
router(tn3270-lpoint)#exit
 
router(cfg-tn3270)#listen-point 10.10.20.2
router(tn3270-lpoint)#pu pu2 05d99003 dlur
router(tn3270-lpoint-pu)#exit
router(tn3270-lpoint)#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)#listen-point 10.10.20.5
router(tn3270-lpoint)#pu pu3 05d00001 tok 1 24 rmac 4100.cafe.0001 lu-seed pu3###
router(tn3270-lpoint-pu)#exit
router(tn3270-lpoint)#pu pu4 05d00002 tok 1 28 rmac 4100.cafe.0001 lu-seed pu4###
router(tn3270-lpoint-pu)#end
 

The following configuration results from the initial CIP configuration and the configuration dialog:

interface Channel2/2
ip address 10.10.20.126 255.255.255.128
no ip redirects
no keepalive
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
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
listen-point 10.10.20.1
pu PU0 05D99001 dlur
pu PU1 05D99002 dlur
listen-point 10.10.20.2
pu PU2 05D99003 dlur
listen-point 10.10.20.5
pu PU3 05D00001 tok 1 24 rmac 4100.cafe.0001 lu-seed PU3###
pu PU4 05D00002 tok 1 28 rmac 4100.cafe.0001 lu-seed PU4###

logging buffered
! logs Cisco IOS software messages to the internal buffer using the default
! buffer size for the router platform
interface Channel0/0
 no ip address
 no keepalive
 cmpc C010 E5 LPAR1TG READ
 cmpc C010 E6 LPAR1TG WRITE
 cmpc C020 00 LPAR2TG READ
 cmpc C020 01 LPAR2TG WRITE
!
interface Channel0/2
 ip address 172.18.5.1 255.255.255.224
 no keepalive
 lan TokenRing 0
  source-bridge 100 1 8
  adapter 0 4000.4040.0000 ! for cmpc
  adapter 1 4000.6060.0000 ! TN3270 server
  adapter 2 4000.7070.0000
 tn3270-server
  maximum-lus 20000 ! optional
  idle-time 64800 ! optional
  timing-mark ! optional
  tcp-port 24 ! optional
  client 10.10.10.0 255.255.255.0 lu maximum 10000 ! optional
  dlur NETA.TN3270CP NETA.CPAC
   dlus-backup NETA.MVS2 ! optional
   preferred-NNserver NETA.CPAC ! optional
   lsap token-adapter 1 04 ! TN3270 server uses cmcc adapter 1 and sap=04
    link LINK1 rmac 4000.4040.0000 rsap 08 ! link to cmpc on adapter 0
   lsap token-adapter 2 04
    link LINK2 rmac 4000.7070.0000 rsap 08 ! link to cmpc on adapter 2
   listen-point 172.18.5.2
    pu TNPU1 01754321 dlur
!
tg LPAR1TG llc token-adapter 0 08 rmac 4000.6060.0000 rsap 04 ! rsap optional
tg LPAR2TG llc token-adapter 2 08 rmac 4000.7070.0000 ! rsap=04 by default"

interface channel 2/2
tn3270-server
pu BAGE4
client ip 171.69.176.28 255.255.255.0 lu 1 50
 

To remove a nailing definition, the complete range of LOCADDRS must be specified as configured. So for the example above, the following command would remove the LU nailing definition:

no client ip 171.69.176.28 255.255.255.0 lu 1 50

If an attempt is made to remove a subset of the range of configured LOCADDRS then the command is rejected:

no client ip 171.69.176.28 255.255.255.0 lu 1 20
% client ip 171.69.176.28 lu not matched with configured lu 1 50