- access-expression through asptime
- bridge acquire through bstun route all apip
- certificate reload through csna
- default-profile through dspu vdlc start
- enable (TN3270) through lu termination
- mac-address through vsrb remote-peer netbios-output-list
- sap-priority through servercert
- show access-expression through show extended channel udp-stack
- show fras through shutdown (TN3270)
- sna enable-host (Token Ring, Ethernet, Frame Relay, FDDI) through source-bridge max-in-hops
- source-bridge max-out-hops through x25 pvc qllc
- Appendix: Ethernet Type Codes
- sap-priority
- sap-priority-list
- sdlc address
- sdlc dlsw
- sdlc dte-timeout
- sdlc frmr-disable
- sdlc holdq
- sdlc k
- sdlc line-speed
- sdlc n1
- sdlc n2
- sdlc partner
- sdlc poll-limit-value
- sdlc poll-pause-timer
- sdlc poll-wait-timeout
- sdlc qllc-prtnr
- sdlc role
- sdlc saps
- sdlc sdlc-largest-frame
- sdlc simultaneous
- sdlc slow-poll
- sdlc snrm-timer
- sdlc t1
- sdlc test serial
- sdlc virtual-multidrop
- sdlc vmac
- sdlc xid
- sdlc xid-pause-timer
- sdllc partner
- sdllc ring-largest-frame
- sdllc sap
- sdllc sdlc-largest-frame
- sdllc traddr
- sdllc xid
- sec-profile
- security (TN3270)
- servercert
sap-priority
To define a priority list on an interface, use the sap-priority command in interface configuration mode. To remove a priority list on an interface, use the no form of this command.
sap-priority list-number
no sap-priority list number
Syntax Description
list-number |
Priority list number you specified in the sap-priority-list command. |
Defaults
No priority list is defined.
Command Modes
Interface configuration
Command History
Examples
The following example specifies priority list number 1:
sap-priority 1
Related Commands
|
|
---|---|
sap-priority-list |
Defines a priority list. |
source-bridge |
Configures an interface for source-route bridging (SRB). |
sap-priority-list
To define a priority list, use the sap-priority-list command in global configuration mode. To remove a priority list, use the no form of this command.
sap-priority-list list-number queue-keyword [dsap ds] [ssap ss] [dmac dm] [smac sm]
no sap-priority-list list-number queue-keyword [dsap ds] [ssap ss] [dmac dm] [smac sm]
Syntax Description
Defaults
No priority list is defined.
Command Modes
Global configuration
Command History
Usage Guidelines
To give precedence to traffic on a particular Logical Link Control, type 2 (LLC2) session, you must specify all four keywords (dsap, ssap, dmac, and smac) to uniquely identify the LLC2 session.
Examples
The following example defines priority list 1 and specifies source service access point (SSAP) and destination service access point (DSAP) addresses:
sap-priority-list 1 high dsap 04 ssap 04
sdlc address
To assign a set of secondary stations attached to the serial link, use the sdlc address command in interface configuration mode. To remove an assigned secondary station use the no form of this command.
sdlc address hexbyte [echo] [ack-mode] [xid-poll] [switched] [seconly] [xid-passthru] [passive] [K number] [vmac vmac-address]
no sdlc address hexbyte [echo] [ack-mode] [xid-poll] [switched] [seconly] [xid-passthru] [passive] [K number] [vmac vmac-address]
Syntax Description
Defaults
No secondary stations are assigned.
Command Modes
Interface configuration
Command History
Usage Guidelines
To assign the IBM reserved address ff as a nonbroadcast valid local address, configure the sdlc address interface configuration command with a hexbyte value of ff and specify the ack-mode option. To deactivate, use the no form of the command.
Before you can use this command, you must specify the encapsulation on the interface on which you want to enable SDLC; then, establish the router link station role. Next, assign secondary station addresses using the sdlc address command. The addresses are given one per line in hexadecimal (base 16).
The sdlc address ff ack-mode command is used to support applications that require local termination on an SDLC connection with address ff. This command should be used only if you use the SDLC address ff as a regular (not a broadcast) address.
The optional echo keyword is valid only for TG interfaces. When you use the echo keyword, the hexbyte argument is the non-echo SDLC address.
The optional passive keyword is valid only when the role is primary. When you use the passive keyword, the sdlc partner command is required with keyword inbound specified.
Examples
The following example shows how to configure serial interface 0 with two SDLC secondary stations attached to it through a modem-sharing device with addresses C1 and C2:
interface serial 0
encapsulation sdlc
sdlc role primary
sdlc address c1
sdlc address c2
Related Commands
sdlc dlsw
To attach Synchronous Data Link Control (SDLC) addresses to data-link switching plus (DLSw+), use the sdlc dlsw command in interface configuration mode. To cancel the configuration, use the no form of this command.
sdlc dlsw {sdlc-address | default | partner mac-address [inbound | outbound]}
no sdlc dlsw {sdlc-address | default | partner mac-address [inbound | outbound]}
Syntax Description
Defaults
No correspondence is defined between SDLC addresses and DLSw+.
Command Modes
Interface configuration
Command History
Examples
The following command attaches SDLC address d2 to DLSw+:
sdlc dlsw d2
The following command attaches SDLC addresses d2, d5, e3, e4, e6, b1, c3, d4, a1 and a5:
sdlc dlsw d2 d5 e3 e4 e6 b1 c3 d4 a1 a5
Related Commands
sdlc dte-timeout
To adjust the amount of time a DTE interface waits for the DCE to assert a Clear To Send (CTS) signal before dropping a Request To Send (RTS), use the sdlc dte-timeout command in interface configuration mode. To revert to the default setting, use the no form of this command.
sdlc dte-timeout unit
no sdlc dte-timeout unit
Syntax Description
unit |
Timeout wait interval in microseconds. The valid range is from 10 to 64000. Each unit is approximately 5 microseconds. The default is 10 units (approximately 50 microseconds). |
Defaults
10 units (approximately 50 microseconds)
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command on an interface that is in half-duplex mode and that has been configured for DTE.
Examples
The following example sets the amount of time that the DTE waits for the DCE to assert a CTS to 100 units (approximately 500 microseconds):
sdlc dte-timeout 100
Related Commands
sdlc frmr-disable
To indicate that secondary stations on a particular serial link do not support Frame Rejects (FRMRs) or error indications, use the sdlc frmr-disable command in interface configuration mode. To specify that the secondary station does support FRMRs, use the no form of this command.
sdlc frmr-disable
no sdlc frmr-disable
Syntax Description
This command has no arguments or keywords.
Defaults
This command is disabled, which means that secondary stations support FRMRs or error indications.
Command Modes
Interface configuration
Command History
Usage Guidelines
FRMRs are error indications that can be sent to a Synchronous Data Link Control (SDLC) station indicating that a protocol error has occurred. Not all SDLC stations support FRMRs. If this command is enabled, when the Cisco IOS software receives an error, it drops the line by sending a disconnect request to the remote station.
Examples
In the following example, the software is set to drop the serial line when it receives a protocol error:
interface serial 0
sdlc frmr-disable
Related Commands
|
|
---|---|
show llc2 |
Displays the LLC2 connections active in the router. |
sdlc holdq
To control the maximum number of packets that can be held in a buffer before being sent to a remote Synchronous Data Link Control (SDLC) station, use the sdlc holdq command in interface configuration mode. To revert to the default setting, use the no form of this command.
sdlc holdq address queue-size
no sdlc holdq address queue-size
Syntax Description
address |
SDLC address for which you are specifying a queue size. |
queue-size |
Local send window size. The minimum is 1 packet. No maximum value has been established. The default is 200 packets. |
Defaults
200 packets
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is particularly useful with the SDLC Logical Link Control. Cisco (SDLLC) feature that allows a SDLC Logical Link Control. Cisco (SDLLC)-speaking Systems Network Architecture (SNA) station on a Token Ring to communicate with an SDLC-speaking SNA station on a serial link. Frame sizes and window sizes on Token Rings are often much larger than those acceptable for serial links. The fact that serial links are often much slower than Token Rings often makes this problem worse. Therefore, temporary backlogs can exist in periods of high data transfer from the Token Ring station to the serial station. A buffer creates a holding place for backlogged frames waiting to be sent on the serial link. This command is specified for each SDLC address, and therefore, for each SDLC secondary station on the serial link.
Examples
The following example shows how to change the output hold queue length to 30 frames on an SDLC station of address C1 off serial interface 0:
interface serial 0
encapsulation sdlc-primary
sdlc address c1
sdlc holdq c1 30
Related Commands
|
|
---|---|
show llc2 |
Displays the Logical Link Control, type 2 (LLC2) connections active in the router. |
sdlc k
To set the window size in order to control the maximum number of information frames the Cisco IOS software sends before it must stop sending and wait for an acknowledgment from the receiving router, use the sdlc k command in interface configuration mode. To revert to the default setting, use the no form of this command.
sdlc k window-size
no sdlc k window-size
Syntax Description
window-size |
Local send window size. The minimum is one frame. The maximum is seven frames, which is the default. |
Defaults
Seven frames
Command Modes
Interface configuration
Command History
Usage Guidelines
When the Cisco IOS software is communicating with Synchronous Data Link Control (SDLC), it must have a parameter that controls the maximum number of information frames it will send before it must stop sending and wait for an acknowledgment. The k parameter keyword controls this window of acceptable frames. Use this command in conjunction with the sdlc n1 command to create a balance between frame checking and network performance.
Examples
In the following example, the software can send up to five frames before it must receive an acknowledgment:
! enter a global command, if you have not already
interface tokenring 0
!send up to 5 frames, then wait for acknowledgment
sdlc k 5
Related Commands
|
|
---|---|
sdlc n1 |
Controls the maximum size of an incoming frame. |
show llc2 |
Displays the Logical Link Control, type 2 (LLC2) connections active in the router. |
sdlc line-speed
To enable adaptive Synchronous Data Link Control (SDLC) T1, use the sdlc line-speed command in interface configuration mode. To deactivate the command, use the no form of this command.
sdlc line-speed rate
no sdlc line-speed rate
Syntax Description
rate |
Clock rate in bits per second. |
Defaults
No default rate
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is used to calculate the adjusted SDLC T1 value. The adjusted T1 is used to compensate for the delay between the time the system software passes a packet to the microcode, and the time the packet is actually sent out on the line. For a DCE device, this should be equal to the clock rate on the interface. For a DTE device, it should be equal to the clock rate on the DCE device to which the DTE is connected.
Examples
In the following example, the SDLC line-speed rate is set to rate:
sdlc line-speed rate
Related Commands
sdlc n1
To control the maximum size of an incoming frame, use the sdlc n1 command in interface configuration mode. To revert to the default setting, use the no form of this command.
sdlc n1 bit-count
no sdlc n1 bit-count
Syntax Description
Defaults
12000 bits
Command Modes
Interface configuration
Command History
Usage Guidelines
Use with the sdlc k command to reduce network overhead while continuing to check the sending of frames.
The formula for determining the maximum allowed value for the bit-count argument is the maximum MTU value of the interface + 2 bytes (for the Synchronous Data Link Control [SDLC] header) multiplied by 8 (to convert from bytes to bits). For example, if the maximum MTU of the interface is 1500 bytes, then the largest value for the bit-count argument is (1500 + 2) * 8 = 12016 bits. Usually, the default maximum MTU size is 1500 bytes, but it can be configured as high as 18,000 bytes.
Examples
In the following example, the Cisco IOS software rejects frames larger than 10,000 bits:
interface serial 0
sdlc n1 10000
Related Commands
sdlc n2
To determine the number of times that the Cisco IOS software resends a frame before terminating the Synchronous Data Link Control (SDLC) session, use the sdlc n2 command in interface configuration mode. To revert to the default setting, use the no form of this command.
sdlc n2 retry-count
no sdlc n2 retry-count
Syntax Description
retry-count |
Number of retry attempts. When this number is exceeded, the SDLC station terminates its session with the other station. The minimum is 1 and the maximum is 255. The default is 20 retries. |
Defaults
20 retries
Command Modes
Interface configuration
Command History
Usage Guidelines
Use the sdlc n2 command with the sdlc t1 command to reduce network overhead while continuing to check the sending of data.
Examples
In the following example, the software is set to drop an SDLC station after five unsuccessful attempts to receive an acknowledgment for a frame:
interface serial 0
sdlc n2 5
Related Commands
sdlc partner
To specify the destination address with which a Logical Link Control (LLC) session is established for the Synchronous Data Link Control (SDLC) station, use the sdlc partner command in interface configuration mode. To cancel the configuration, use the no form of this command.
sdlc partner mac-address sdlc-address {inbound | outbound}
no sdlc partner mac-address sdlc-address {inbound | outbound}
Syntax Description
Defaults
No partner is defined.
Command Modes
Interface configuration
Command History
Usage Guidelines
The inbound keyword prevents unwanted messages on the host operator console from inbound XIDs to inactive virtual telecommunications access method (VTAM) Switched Major Nodes. It directs SDLC to not send Test or XID frames to the host, front-end processor (FEP), or 3172 even after the connection to a downstream PU2 is complete. The inbound keyword is required for System88 support.
Examples
The following example establishes the correspondence between an SDLC and Qualified Logical Link Control (QLLC) connection:
sdlc partner 1000.5aed.1f53 d2 inbound
Related Commands
sdlc poll-limit-value
To control how many times a single secondary station can be polled for input before the next station must be polled, use the sdlc poll-limit-value command in interface configuration mode. To revert to the default setting, use the no form of this command.
sdlc poll-limit-value count
no sdlc poll-limit-value count
Syntax Description
count |
Number of times the Cisco IOS software can poll one secondary station before proceeding to the next station. The valid range is from 1 through 10. The default is 1. |
Defaults
1 time
Command Modes
Interface configuration
Command History
Usage Guidelines
As is typical for the primary station of an Synchronous Data Link Control (SDLC) connection, if a secondary station sends its full possible window of input to the primary router or access server, the Cisco IOS software immediately will re-poll the same secondary for more data in an attempt to capture the complete transaction at one time. The sdlc poll-limit-value command indicates how many times this can happen before the next station in the poll loop must be polled.
Increasing the value allows for smoother transaction processing but can delay polling of other stations or giving output to other stations.
Examples
The following example specifies that the router can be polled two times before the next station in the poll list must be polled:
! enter a global command, if you have not already
interface serial 4
no ip address
! use stun encapsulation
encapsulation stun
! establish stun group 4 on interface serial 4
stun group 4
stun sdlc-role primary
! poll the router up to two times before polling the next station
sdlc poll-limit-value 2
Related Commands
sdlc poll-pause-timer
To control how long the Cisco IOS software pauses between sending each poll frame to secondary stations on a single serial interface, use the sdlc poll-pause-timer command in interface configuration mode. To revert to the default setting, use the no form of this command.
sdlc poll-pause-timer milliseconds
no sdlc poll-pause-timer milliseconds
Syntax Description
milliseconds |
Number of milliseconds (ms) that the software waits before sending the poll frame to a single serial interface. This is a number in the range from 1 to 10000. The default is 10 ms. |
Defaults
10 ms
Command Modes
Interface configuration
Command History
Usage Guidelines
As is typical for the primary station of a Synchronous Data Link Control (SDLC) connection, the software generates polls periodically to each of the secondary stations to solicit their input. After polling each station on a single serial interface, the software will pause before beginning to poll the next station.
Because the secondaries cannot send data until they are polled, increasing this timer value can increase response time to the users. However, making this value too small can flood the serial link with unneeded polls and require the secondary stations to spend wasted CPU time processing them.
Examples
In the following example, the software pauses 2000 ms before sending a series of poll frames through serial interface 4:
! enter a global command, if you have not already
interface serial 4
no ip address
! use STUN encapsulation
encapsulation stun
! establish stun group 4 on interface serial 4
stun group 4
!
stun sdlc-role primary
! wait 2000 milliseconds before sending each series of poll frames
sdlc poll-pause-timer 2000
Related Commands
sdlc poll-wait-timeout
To specify the interval the Cisco IOS software will wait for polls from a primary node before timing out that connection when the router has been configured for local acknowledgment and some form of Synchronous Data Link Control (SDLC) communication (SDLLC or serial tunnel [STUN], for example), use the sdlc poll-wait-timeout command in interface configuration mode. To revert to the default setting, use the no form of this command.
sdlc poll-wait-timeout milliseconds
no sdlc poll-wait-timeout milliseconds
Syntax Description
Defaults
10000 ms
Command Modes
Interface configuration
Command History
Usage Guidelines
This command can be used on an interface that has been configured as a secondary node, but is not to be used on an interface that has been configured as a primary node.
In a locally acknowledged multidrop environment, the polls the primary node sends to the router can be delayed because the primary node is busy polling other secondary nodes. In such situations, this command can be used to extend the timeout, thus reducing the likelihood the Cisco IOS software times out the connection to the primary node.
Examples
The following example specifies that the local software will wait an interval of 63,000 ms for a poll from a primary station before timing out:
! sample stun peer-name global command
stun peer-name 10.136.134.86
! sample protocol-group command
stun protocol-group 4 sdlc
!
interface serial 0
! sample ip address command
no ip address
! sample encapsulation stun command
encapsulation stun
! place interface serial0 in previously defined STUN group 4
stun group 4
! must enter the next command to use the sdlc poll-wait-timeout command
stun sdlc-role secondary
! set timeout period for polls from primary station to 63000 milliseconds.
sdlc poll-wait-timeout 63000
! list the addresses of the sdlc stations on the link
sdlc address C1
sdlc address C2
! provide stun route command
stun route address C2 tcp 10.136.134.58
stun route address C1 tcp 10.136.134.58
Related Commands
sdlc qllc-prtnr
To establish correspondence between a Synchronous Data Link Control (SDLC) and Qualified Logical Link Control (QLLC) connection, use the sdlc qllc-prtnr command in interface configuration mode. To deactivate the command, use the no form of this command.
sdlc qllc-prtnr virtual-mac-address sdlc-address
no sdlc qllc-prtnr virtual-mac-address sdlc-address
Syntax Description
virtual-mac-address |
The virtual MAC address in the form h.h.h. |
sdlc-address |
SDLC address in hexadecimal. The valid range is from 1 to FE. |
Defaults
No correspondence is defined.
Command Modes
Interface configuration
Command History
Examples
The following example establishes the correspondence between an SDLC and QLLC connection:
sdlc qllc-prtnr 4000.0122.0001 c1
Related Commands
|
|
---|---|
show llc2 |
Displays the Logical Link Control, type 2 (LLC2) connections active in the router. |
sdlc role
To establish the router to be either a primary or secondary Synchronous Data Link Control (SDLC) station, use the sdlc role command in interface configuration mode. To cancel the designation, use the no form of this command.
sdlc role {none | primary | secondary | prim-xid-poll}
no sdlc role {none | primary | secondary | prim-xid-poll}
Syntax Description
Defaults
No default role is assigned.
Command Modes
Interface configuration
Command History
Usage Guidelines
If the role is none, the router can be either primary or secondary, depending on the end stations. The SDLC end station must be configured as negotiable or primary NT2.1. When the end stations are configured as physical unit type 2 (physical unit [PU] 2), you can set the role of the interface to primary or secondary. When the end station is configured as secondary NT2.1, you must set the role of the interface to prim-xid-poll.
To configure an SDLC multidrop line (downstream), configure the SDLC role as follows:
•primary if all SDLC devices are type PU 2.0 or mixed PU 2.0 and 2.1
•prim-xid-poll if all devices are type PU 2.1
Examples
The following example configures the router as a primary SDLC station:
interface serial 2/6
no ip address
encapsulation sdlc
fras map sdlc c1 serial 2/0 frame-relay 32 4 4
sdlc role primary
sdlc address c1
sdlc xid c1 01700001
Related Commands
|
|
---|---|
encapsulation sdlc |
Configures an SDLC interface. |
sdlc saps
To configure Synchronous Data Link Control (SDLC)-to-Logical Link Control (LLC) sessions with respect to the source service access point (SSAP) and destination service access point (DSAP) on the LLC, use the sdlc saps command in interface configuration mode. To return to the default setting, use the no form of this command.
sdlc saps address ssap dsap
no sdlc saps address ssap dsap
Syntax Description
Defaults
The default value for both the ssap and dsap arguments is 04.
Command Modes
Interface configuration
Command History
Examples
The following example configures SDLC address 01, SSAP 08, and DSAP 08.
sdlc saps 01 08 08
sdlc sdlc-largest-frame
To indicate the largest information frame (I-frame) size that can be sent or received by the designated Synchronous Data Link Control (SDLC) station, use the sdlc sdlc-largest-frame command in interface configuration mode. To return to the default value, use the no form of this command.
sdlc sdlc-largest-frame address size
no sdlc sdlc-largest-frame address size
Syntax Description
address |
Address of the SDLC station that will communicate with the router. |
size |
Largest frame size that can be sent or received. The default is 265 bytes. |
Defaults
The default size for the largest I-frame is 265 bytes.
Command Modes
Interface configuration
Command History
Examples
In the following example, the Cisco IOS software can send or receive a frame as large as 265 bytes (the default) from the SDLC station at address C6. Any frames larger will be fragmented by the software.
interface serial 4
sdlc sdlc-largest-frame c6 265
sdlc simultaneous
To enable an interface configured as a primary Synchronous Data Link Control (SDLC) station to operate in two-way simultaneous mode, use the sdlc simultaneous command in interface configuration mode. To revert to the default setting, use the no form of this command.
sdlc simultaneous [full-datamode | half-datamode]
no sdlc simultaneous [full-datamode | half-datamode]
Syntax Description
Defaults
Two-way simultaneous mode is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
By default, the SDLC driver supports alternative mode. This means that in a multidrop environment, the primary station cannot send data to another secondary station until it receives a response (F bit) from the secondary station with which it is communicating.
In contrast, two-way simultaneous mode enables the interface configured as a primary SDLC station to send data to a second secondary station, even when it is receiving data from another secondary station. This capability improves utilization of a full-duplex serial line.
Examples
The following example enables all primary stations to send and receive data at the same time:
sdlc simultaneous full-datamode
The following example enables all secondary stations to send or receive data at the same time:
sdlc simultaneous half-datamode
Related Commands
sdlc slow-poll
To enable the slow-poll capability of the router as a primary Synchronous Data Link Control (SDLC) station, use the sdlc slow-poll command in interface configuration mode. To disable slow-poll capability, use the no form of this command.
sdlc slow-poll seconds
no sdlc slow-poll
Syntax Description
seconds |
Amount of time in seconds. The default is 10 seconds. |
Defaults
10 seconds
Command Modes
Interface configuration
Command History
Usage Guidelines
You can use this command to improve the performance of a multidropped SDLC configuration when one or more of the secondary stations are inactive.
When slow-poll is enabled, if the router acting as a primary station detects that a secondary SDLC station is not responding, it polls that secondary SDLC station less frequently. The router spends less time waiting for the inactive secondary station to respond, thereby minimizing the performance degradation on the active secondary SDLC stations on the multidropped line.
Examples
The following example enables the slow-poll capability:
interface serial 0
sdlc slow-poll
Related Commands
sdlc snrm-timer
To specify a Set Normal Response (SNRM) timer that is different from the T1 response time, set the Synchronous Data Link Control (SDLC) SNRM timer using the sdlc snrm-timer command in interface configuration mode. To deactivate, use the no form of this command.
sdlc snrm-timer number
no sdlc snrm-timer number
Syntax Description
Defaults
No default behavior or values
Command Modes
Interface configuration
Command History
Usage Guidelines
Use the SNRM timer only if you want to have a unique timeout period to wait for a reply to an SNRM.
The sdlc snrm-timer command is used to specify the time to wait for a reply to an SNRM frame in milliseconds. This command is enabled only if the station role is primary.
Examples
The following configuration defines serial interface 0 as the primary SDLC station with two SDLC secondary stations, C1 and C2, attached to it through a modem-sharing device. SDLC simultaneous half-datamode is enabled, and the time to wait for a reply to a SNRM frame is 2500 ms.
interface serial 0
encapsulation sdlc
sdlc role primary
sdlc address c1
sdlc address c2
sdlc simultaneous half-datamode
sdlc snrm-timer 2500
Related Commands
sdlc t1
To control the amount of time the Cisco IOS software waits for an acknowledgment to a frame or sequence of frames, use the sdlc t1 command in interface configuration mode. To revert to the default setting, use the no form of this command.
sdlc t1 milliseconds
no sdlc t1 milliseconds
Syntax Description
milliseconds |
Number of milliseconds that the software waits. The minimum is 1 ms and the maximum is 64000 ms. The default is 3000 ms. |
Defaults
3000 ms
Command Modes
Interface configuration
Command History
Usage Guidelines
When an Synchronous Data Link Control (SDLC) station sends a frame, it waits for an acknowledgment from the receiver that the frame has been received. The sending station cannot wait indefinitely for a response. When the frame is sent, a timer is started. To be consistent with the original specification of SDLC, this timer is called the T1 timer and is controlled by this parameter. If this timer reaches its limit before the acknowledgment is received, the software will try again and resend the frame.
Examples
In the following example, the software waits up to 4000 ms for a reply to a frame or sequence of frames:
! enter a global command, if you have not already
interface tokenring 0
sdlc t1 4000
Related Commands
sdlc test serial
To determine the status of end stations, use the sdlc test serial command in user EXEC or privileged EXEC mode. To halt the sending of the test frames, use the sdlc test serial command with the stop keyword.
sdlc test serial number address [iterations | continuous | stop | string string]
Syntax Description
Defaults
The sdlc test serial command is not active.
The default number of test frames sent is 10.
The default test string is ABCDEFGHIJKLMNOPQRSTUVWXYZ.
Command Modes
User EXEC
Privileged EXEC
Command History
Usage Guidelines
The command will precheck for correct interface and SDLC address. The results of the test frames sent can be displayed after the frames have been sent or an sdlc test serial command with the stop keyword has been issued.
There is not a no form for this command.
Examples
The following are variations of the sdlc test serial command, followed by the response for each:
Router#
sdlc test serial 0 c1
SDLC Test for address C1 completed
Frames sent=10 Frames received=10
Router# sdlc test serial 0 c1 255
SDLC Test for address C1 completed
Frames sent=255 Frames received=255
Router# sdlc test serial 0 C1 stop
SDLC Test for address C1 completed
Frames sent=44 Frames received=44
Router# sdlc test serial 0 c1 string Thestuffofdreams
SDLC Test for address C1 completed
Frames sent=10 Frames received=10
Related Commands
|
|
---|---|
show llc2 |
Displays the Logical Link Control, type 2 (LLC2) connections active in the router. |
sdlc virtual-multidrop
To allow Synchronous Data Link Control (SDLC) broadcast address FF to be replicated for each of the serial tunnel (STUN) peers, so that each of the end stations receives the broadcast frame, use the sdlc virtual-multidrop command in interface configuration mode. To disable the SDLC broadcast feature, use the no form of this command.
sdlc virtual-multidrop
no sdlc virtual-multidrop
Syntax Description
This command has no arguments or keywords.
Defaults
SDLC broadcast is disabled.
Command Modes
Interface configuration
Command History
Examples
The following example allows each STUN peer to receive a broadcast frame:
sdlc virtual-multidrop
Related Commands
|
|
---|---|
stun route address tcp |
Specifies TCP encapsulation and optionally establishes SDLC local acknowledgment (SDLC transport) for STUN. |
sdlc vmac
To configure a MAC address for the serial interface, use the sdlc vmac command in interface configuration mode. To disable the configuration, use the no form of this command.
sdlc vmac mac-address
no sdlc vmac mac-address
Syntax Description
mac-address |
48-bit MAC address of the Token Ring host. |
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
This command must be configured if you will configure data-link switching plus (DLSw+). The last byte of the address must be 00.
Examples
The following example specifies a MAC address for the serial interface:
sdlc vmac 1234.3174.0000
Related Commands
|
|
---|---|
encapsulation sdlc |
Configures an Synchronous Data Link Control (SDLC) interface. |
sdlc dlsw |
Attaches SDLC addresses to DLSw+. |
sdlc xid
To specify an exchange identification (XID) value appropriate for the designated Synchronous Data Link Control (SDLC) station associated with this serial interface, use the sdlc xid command in interface configuration mode. To disable XID processing for this address, use the no form of this command.
sdlc xid address xid
no sdlc xid address xid
Syntax Description
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
XID requests and responses are usually exchanged before sessions are started. Be sure that the XID value configured in the Cisco IOS software matches the IDBLK and IDNUM parameters configured on the host. The XID response to an XID request will contain the information you configured in the sdlc xid command. The host will check the XID response it receives with the IDBLK and IDNUM parameters (that are configured in the virtual telecommunications access method [VTAM]). If they match, the host will initiate a session with the router. If they do not match, the host will not initiate a session.
Examples
The following example specifies an XID value of 01720002 at address C2:
interface serial 0
sdlc xid c2 01720002
Related Commands
|
|
---|---|
encapsulation sdlc |
Configures an SDLC interface. |
sdlc xid-pause-timer
To control the frequency of exchange identification (XID) retries between a router and an upstream virtual telecommunications access method (VTAM), use the sdlc xid-pause-timer command in interface configuration mode. To restore the default timer value, use the no form of this command.
sdlc xid-pause-timer time
no sdlc xid-pause-timer time
Syntax Description
time |
Length of time the router is to wait, in seconds, before sending the next retry XID. The valid range is from 10 to 300 seconds. The default is 10 seconds. |
Defaults
The default XID pause timer value is 10 seconds.
Command Modes
Interface configuration
Command History
Usage Guidelines
When a router attempts to send an XID upstream to VTAM, and the switched major node is down, the router continues to send retry XIDs at 10-second intervals. If many other routers are also attempting to send retry XIDs to VTAM, the resulting XID flood can cause problems. The sdlc xid-pause-timer command enables you to control the interval between router XID retries.
Examples
The following example specifies an XID pause timer value of 60 seconds:
interface serial 0
sdlc xid-pause-timer 60
sdllc partner
To enable device-initiated connections for SDLC Logical Link Control. Cisco (SDLLC), use the sdllc partner command in interface configuration mode. This command must be specified for the serial interface that links to the serial line device. To cancel the original instruction, use the no form of this command.
sdllc partner mac-address sdlc-address
no sdllc partner mac-address sdlc-address
Syntax Description
mac-address |
MAC address of the Token Ring host. |
sdlc-address |
Synchronous Data Link Control (SDLC) address of the serial device that will communicate with the Token Ring host. |
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
Both the MAC address of the Token Ring host and the SDLC serial line address must be configured to initiate connections with the Token Ring host.
The Token Ring host and the serial device communicate with each other through the Cisco IOS software. Although the device is said to initiate connections, the software actually initiates connections with the Token Ring host on behalf of the serial device. As part of Cisco's SDLLC implementation, the serial device "thinks" that it is communicating with a host also on a serial line. It is actually the software that does all the frame and protocol conversions between serial and Token Ring devices.
There are two conditions under which the Cisco IOS software will attempt to initiate a connection to a host on behalf of a serial device:
•When the serial device attached to the router is powered on. In this case, the router attached to the serial line detects a change in interface signals and initiates a connection with the Token Ring hosts by exchanging explorer and exchange identification (XID) packets.
•When a serial interface previously shut down is brought back online. When the no shutdown command is issued, the software will detect a change in the serial line state from down to up and initiate a session with the Token Ring host by exchanging explorer and XID packets.
The Cisco IOS software will continue trying once a minute to initiate a connection whenever one of these two conditions is met, until the host responds to its requests. When you no longer want the software to initiate connections with a host, use the no sdllc partner command.
Note For device-initiated sessions, the host will check the IDBLK and IDNUM parameters of the serial device it receives in the XID packet against the information configured on the host. If the information in the XID packet does not match with what is configured on the host, the host will drop the session. Therefore, for device-initiated connections, always specify the correct IDBLK and IDNUM parameters on the router serial interfaces with the sdllc xid command.
Examples
In the following example, a serial device at SDLC address C2 wants to initiate a connection with a Token Ring host at MAC address 4000.0122.0001. The router initiates the connection on behalf of a serial device:
! sample global command
source-bridge ring-group 100
!
interface serial 0
! router initiates connections with Token Ring host at MAC address
! 4000.0122.0001 on behalf of serial device c2
sdllc partner 4000.0122.0001 c2
Related Commands
|
|
---|---|
sdllc xid |
Specifies an XID value appropriate for the designated SDLC station associated with this serial interface. |
sdllc ring-largest-frame
To indicate the largest I-frame size that can be sent to or received from the Logical Link Control, type 2 (LLC2) primary station, use the sdllc ring-largest-frame command in interface configuration mode. To return to the default, use the no form of this command.
sdllc ring-largest-frame bytes
no sdllc ring-largest-frame bytes
Syntax Description
bytes |
Frame size in bytes. Values are 516, 1500, 2052, 4472, 8144, 11407, and 17800. The default is 516 bytes. |
Defaults
516 bytes
Command Modes
Interface configuration
Command History
Usage Guidelines
Values for the bytes argument match those for the lf size of the various source-bridge remote-peer commands. You must ensure that your remote peer connection can support this largest frame size. Values for the bytes argument are 516, 1500, 2052, 4472, 8144, 11407, and 17800.
Faster screen updates to 3278-style terminals often can be obtained by allowing the Token Ring front-end processor (FEP) to send as large a frame as possible and by allowing the Cisco IOS software to segment the frame into multiple Synchronous Data Link Control (SDLC) I-frames.
Examples
In the following example, the software can send or receive a frame as large as 11407 bytes from the Logical Link Control, type 2 (LLC2) primary station. Any frames larger will be fragmented by the software.
! sample global command
source-bridge ring-group 100
!
interface serial 3
! largest frame sent or received on serial 3 is 11407 bytes
sdllc ring-largest-frame 11407
Related Commands
sdllc sap
To associate a service access point (SAP) value other than the default SAP value with a serial interface configured for SDLC Logical Link Control. Cisco (SDLLC), use the sdllc sap command in interface configuration mode. To return this SAP value to its default state, use the no form of this command.
sdllc sap sdlc-address ssap dsap
no sdllc sap sdlc-address ssap dsap
Syntax Description
Defaults
The default source SAP value for IBM Systems Network Architecture (SNA) devices is 4.
The default destination SAP value for IBM SNA devices is 4.
Command Modes
Interface configuration
Command History
Usage Guidelines
You use the sdllc sap command in conjunction with the sdllc traddr command in interface configuration modes. A SAP can be viewed as a port through which a higher-layer application can communicate with its counterpart (peer) operating on another system. Although the standard SAP value for IBM SNA devices is 4, and NetBIOS devices is xF0, other values are allowed.
Examples
In the following example, source SAP and destination SAP values of 2 are specified for the remote SDLC device at the SDLC address C1 02 02:
interface serial 0
sdllc sap c1 02 02
Related Commands
|
|
---|---|
sdllc traddr |
Enables SDLLC media translation on a serial interface. The address specified is a MAC address to be assigned to the serial station. |
sdllc sdlc-largest-frame
To indicate the largest information frame (I-frame) size that can be sent or received by the designated Synchronous Data Link Control (SDLC) station, use the sdllc sdlc-largest-frame command in interface configuration mode. To return to the default value, use the no form of this command.
sdllc sdlc-largest-frame address value
no sdllc sdlc-largest-frame address value
Syntax Description
address |
Address of the SDLC station that will communicate with the Token Ring host. |
value |
Largest frame size that can be sent or received by this SDLC station. The default is 265 bytes. |
Defaults
265 bytes
Command Modes
Interface configuration
Command History
Usage Guidelines
Most SDLC devices are limited to frames of 265 bytes. I-frames received from the Token Ring station that are larger than this size will be properly fragmented.
Examples
In the following example, the Cisco IOS software can send or receive a frame as large as 265 bytes (the default) from the SDLC station at address C6. Any frames larger will be fragmented by the software.
! sample global command
source-bridge ring-group 100
!
interface serial 4
! largest frame sent or received on serial 4 is 265 bytes
sdllc sdlc-largest-frame c6 265
sdllc traddr
To enable SDLC Logical Link Control. Cisco (SDLLC) media translation on a serial interface, use the sdllc traddr command in interface configuration mode. To disable SDLLC media translation on the interface, use the no form of this command.
sdllc traddr mac-address vrn bn trn
no sdllc traddr mac-address vrn bn trn
Syntax Description
mac-address |
MAC address to be assigned to the serial interface. |
vrn |
SDLLC virtual ring number. |
bn |
SDLLC bridge number. |
trn |
SDLLC target ring number. |
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
The address specified is a MAC address to be assigned to the serial station.
Every control unit hooked off the serial line requires a virtual Token Ring address (VTRA). This usually is assigned by the system administrator as a locally administered MAC address (unique across the network).
When you enable SDLLC media translation by specifying the sdllc traddr command on a serial interface, you must specify a VTRA for each serial station attached to the serial line. The last two hexadecimal digits (that is, the last byte) of the VTRA must be 00. The Cisco IOS software uses this byte to represent the Synchronous Data Link Control (SDLC) address of a station on the serial link.
Note Addresses in the range from xxxx.xxxx.xx00 to xxxx.xxxx.xxFF are reserved for use by the Cisco IOS software. You must adhere to this addressing requirement. If you do not follow this addressing requirement, there may be a conflict between the VTRA and the addresses reserved by the software for the Synchronous Data Link Control (SDLC) link.
The vrn, bn, and trn arguments represent the SDLLC virtual ring number, bridge number, and target ring number, respectively, that you assign to the interface. In design, the serial interface appears to be a ring, vrn, on a source-route bridged network, and ties in through the bridge, bn, to the virtual ring group, trn. This provides access to other, real rings through remote source-route bridging source-bridge remote-peer commands. Note that SDLLC can be configured on a router containing no Token Ring interface cards.
The sdllc traddr command automatically turns on the Logical Link Control, type 2 (LLC2) process with default values. To change any of the LLC2 parameters, specify their values on the serial interface that is being enabled for SDLLC. This is done on the serial interface, even though LLC2 does not run on the serial interface, but on the SDLLC virtual ring associated with the serial interface. LLC2 commands can be configured after specifying the sdllc traddr command.
Examples
In the following example, SDLLC media translation is enabled off the serial 0 interface to a serial station at MAC address 0110.2222.3300. The SDLLC virtual ring number is 8, the bridge number is 1, and the target ring number is 100.
! global command to apply commands to the ring group
source-bridge ring-group 100
! remote peer at IP address 10.108.1.1 belongs to ring group 100 and uses
! tcp as the transport
source-bridge remote-peer 100 tcp 10.108.1.1
source-bridge remote-peer 100 tcp 10.108.2.2
!
interface serial 0
encapsulation sdlc-primary
! establish address of SDLC station off serial-0 as c1
sdlc address c1
! enable SDLLC media translation to serial station 0110.2222.3300
! on virtual ring 8, bridge 1, to target ring 100
sdllc traddr 0110.2222.3300 8 1 100
Related Commands
sdllc xid
To specify an exchange identification (XID) value appropriate for the designated Synchronous Data Link Control (SDLC) station associated with this serial interface, use the sdllc xid command in interface configuration mode. To disable XID processing for this address, use the no form of this command.
sdllc xid address xid
no sdllc xid address xid
Syntax Description
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
Exchange identification (XID) requests and responses are usually exchanged before sessions are started. Be sure that the XID value configured on the router matches the IDBLK and IDNUM parameters configured on the host. The XID response to an XID request from the Token Ring host will contain the information you configured in the sdllc xid command. The host will check the XID response it receives with the IDBLK and IDNUM parameters (that are configured in virtual telecommunications access method (VTAM)). If they match, the Token Ring host will initiate a session with the router. If they do not match, the host will not initiate a session.
Examples
The following example specifies an XID value of 01720002 at address C2:
! sample global command
source-bridge ring-group 100
!
interface serial 0
! sdllc exchange identification value of 01720002 at address c2
sdllc xid c2 01720002
Related Commands
|
|
---|---|
sdllc partner |
Enables device-initiated connections for SDLLC. Must be specified for the serial interface that links to the serial line device. |
sec-profile
To specify a security profile to be associated with a listen point, use the sec-profile command in TN3270 listen-point configuration mode. To remove this specification, use the no form of this command.
sec-profile profilename
no sec-profile profilename
Syntax Description
Defaults
No default behavior or values
Command Modes
TN3270 listen-point configuration
Command History
Usage Guidelines
If this command is not entered or if the no form of the command is entered, the security profile reverts to the profile configured in the default-profile command. If no default profile is specified, the listen point accepts only nonsecure connections
This command has no retroactive effect.
Examples
The following example specifies LAM as the security profile name for all new clients connecting to listen point 10.10.10.1 until the sec-profile LAM1 command is configured. Once the sec-profile LAM1 command is configured, all new client connections to 10.10.10.1 will use LAM1 as the profile name.
tn3270-server
security
profile LAM ssl
keylen 128
servercert slot0:lam
certificate reload
profile LAM1 ssl
keylen 40
servercert slot0:lam1
certificate reload
listen-point 10.10.10.1
sec-profile LAM
pu DIRECT 012ABCDE tok 0 04
Sec-profile LAM1
security (TN3270)
To enable security on the TN3270 server, use the security command in TN3270 server configuration mode. To turn off security on the TN3270 server, use the no form of this command.
security
no security
Syntax Description
This command has no arguments or keywords.
Defaults
The default is to have security enabled.
Command Modes
TN3270 server configuration
Command History
Usage Guidelines
If the no form of this command is configured, any listen points that contain a security profile definition are reconfigured and are no longer secure. Sessions already established on the listen point will continue to run in the same mode (secure or nonsecure) as originally configured. If sessions are active on a listen point, a message will be sent to the console stating that the listen point has sessions running with an outdated security specification. A shutdown/restart sequence must be performed on the listen point if the user wants the sessions on the listen point to use the new specification.
Entering the security command moves the user into security configuration mode. Entering the no form of this command moves the user to a TN3270 server configuration mode.
This command has no retroactive effect.
Examples
In the following example, security is enabled on the TN3270 server:
tn3270-server
security
profile secure-1 ss1
servercert
To specify the location of the TN3270 server's security certificate in the router's Flash memory, use the servercert command in profile configuration mode.
servercert location
Syntax Description
location |
Hexadecimal string of up to 63 characters specifying the location of the server's certificate in the Flash memory. |
Defaults
No default behavior or values
Command Modes
Profile configuration
Command History
Usage Guidelines
The certificate is in X.509 format, signed by a certification authority (CA). The certificate must be created offline. It cannot be created using the Cisco IOS software. Use third-party software or a Windows-based utility. The certificate should be in privacy enhanced mail (PEM) or Base 64 format. The output from the certificate generation contains two parts: the certificate and the private key. Concatenate these two files to create a single certificate file in PEM or Base 64 format.
Store the concatenated file in Flash memory using TFIP and the location entered using the servercert location command. If the file does not exist in the Flash memory when the command is entered, an error message is displayed indicating that the file does not exist. The first time this command is configured the certificate is automatically loaded from the specified location. Subsequent changes to the location file do not cause the certificate to be read automatically into system's memory. The certificate reload command must be entered to read the certificate into memory. If the user exits from the profile configuration mode without configuring the servercert command, a warning message is displayed. The warning message indicates that it is mandatory to configure a certificate using the servercert command.
Examples
The following example specifies that slot0:lam is the location of the security certificate:
tn3270-server
security
profile LAM ssl
keylen 512
servercert slot0:lam
certificate reload
Related Commands
|
|
---|---|
profile |
Specifies a name and a security protocol for a security profile and enters profile configuration mode. |