Table Of Contents

show tarp host

show tarp interface

show tarp ldb

show tarp map

show tarp static-adjacencies

show tarp tid-cache

show tarp traffic

tarp allow-caching

tarp arp-request-timer

tarp blacklist-adjacency

tarp cache-timer

tarp enable

tarp global-propagate

tarp ldb-timer

tarp lifetime

tarp map

tarp nselector-type

tarp originate

tarp post-t2-response-timer

tarp propagate

tarp protocol-type

tarp query

tarp resolve

tarp route-static

tarp run

tarp sequence-number

tarp t1-response-timer

tarp t2-response-timer

tarp tid

tarp urc

timers basic (ISO CLNS)

which-route

show tarp host

To display information about a specific TARP router stored in the local TID cache, use the show tarp host command in EXEC mode.

show tarp host tid

Syntax Description

tid	Target identifier of the router from which you want information. Alphanumeric string up to 255 characters.

Command Modes

EXEC

Command History

Release	Modification
11.1	This command was introduced.

Examples

The following is sample output from the show tarp host command:

router# show tarp host artemis

TID of entry: artemis

NET of entry: 49.0001.1111.1111.1111.00

Entry type: DYNAMIC 

Expiration time: 280 seconds

Table 49 describes the fields shown in the display.

Table 49 show tarp host Field Descriptions

Field	Description
TID	Target identifier of the router.
NET	NSAP address of the router.
Entry type	Type of entry in the TID cache. Values are local, dynamic, or static. A static entry is created with the tarp map command.
Expiration time	Amount of time that a dynamically created entry will remain in the TID cache. The cache timer is set by the tarp cache-timer command.

Related Commands

Command	Description
tarp tid	Assigns a TID to the router.

show tarp interface

To list all interfaces that have TARP enabled, use the show tarp interface command in EXEC mode.

show tarp interface [type number]

Syntax Description

type	(Optional) Interface type.
number	(Optional) Interface number.

Command Modes

EXEC

Command History

Release	Modification
11.1	This command was introduced.

Examples

The following is sample output from the show tarp interface command:

router# show tarp interface

Ethernet0 is up, line protocol is up, encapsulation is ARPA

TARP propagation is enabled on this interface

Table 50 describes the fields shown in the display.

Table 50 show tarp interface Field Descriptions

Field	Description
Ethernet...is {up | down} ...is administratively down	Indicates whether the interface hardware is currently active (whether carrier detect is present) or if it has been taken down by an administrator.
line protocol is {up | down | administratively down}	Indicates whether the software processes that handle the line protocol think the line is usable (that is, whether keepalives are successful).
Encapsulation	Indicates the encapsulation method assigned to the interface.
TARP propagation	Indicates whether this interface can propagate TARP PDUs. The propagation is set by the tarp propagate command.

Related Commands

Command	Description
tarp enable	Enables the TARP on an interface.
tarp propagate	Reenables propagation of TARP PDUs on an interface.

show tarp ldb

To display the contents of the loop-detection buffer table, use the show tarp ldb command in EXEC mode.

show tarp ldb

Syntax Description

This command has no arguments or keywords.

Command Modes

EXEC

Command History

Release	Modification
11.1	This command was introduced.

Examples

The following is sample output from the show tarp ldb command:

router# show tarp ldb

   System ID          Sequence Number      Expiration (sec)

  1111.1111.1111              4            240

Table 51 describes the fields shown in the display.

Table 51 show tarp ldb Field Descriptions

Field	Description
System ID	System ID of the router.
Sequence Number	Sequence number of the last packet sent by the router specified by the system ID.
Expiration (sec)	Time, in seconds, left before this entry in the loop-detection buffer table is cleared. The time is set by the tarp ldb-timer command.

Related Commands

Command	Description
clear tarp ldb-table	Clears the system ID-to-sequence number mapping entries stored in the TARP loop-detection buffer table.
tarp sequence-number	Specifies the sequence number to be used in the next outgoing TARP PDU.

show tarp map

To list all static entries in the TID cache that were configured with the tarp map command, use the show tarp map command in EXEC mode.

show tarp map

Syntax Description

This command has no arguments or keywords.

Defaults

None

Command Modes

EXEC

Command History

Release	Modification
11.1	This command was introduced.

Examples

The following is sample output from the show tarp map command:

router# show tarp map

        Static MAP entries:

shashi                          49.0001.6666.6666.6666.00

sonali                          49.0001.7777.7777.7777.00

Table 52 describes the fields shown in the display.

Table 52 show tarp map Field Descriptions

Field	Description
shashi	TID of the static entry.
49.0001.6666.6666.6666.00	NSAP address of the static entry.

Related Commands

Command	Description
clear tarp tid-table	Clears the dynamically created TARP TID-to-NSAP address mapping entries stored in TID cache.
tarp map	Enters a TID-to-NSAP static route in the TID cache.

show tarp static-adjacencies

To list all static TARP adjacencies that are configured with the tarp route-static command, use the show tarp static-adjacencies command in EXEC mode.

show tarp static-adjacencies

Syntax Description

This command has no arguments or keywords.

Command Modes

EXEC

Command History

Release	Modification
11.1	This command was introduced.

Examples

The following is sample output from the show tarp static-adjacencies command:

router# show tarp static-adjacencies

        Manual (static) TARP adjacencies:

        55.0001.0001.1111.1111.1111.1111.1111.1111.1111.00

Table 53 describes the field shown in the display.

Table 53 show tarp static-adjacencies Field Descriptions

Field	Description
55.0001.0001.1111.1111.1111.1111.1111.1111.1111.0	NSAP address of the TARP adjacency.

Related Commands

Command	Description
tarp route-static	Configures a static TARP adjacency.

show tarp tid-cache

To display information about the entries in the TID cache, use the show tarp tid-cache command in EXEC mode. Entries are created dynamically, statically, or as a result of assigning a TID to the device by using the tarp tid command.

show tarp tid-cache [detail]

Syntax Description

detail

(Optional) List additional information in the TID/NET cache (such as the expiration time for dynamic entries).

Command Modes

EXEC

Command History

Release	Modification
11.1	This command was introduced.

Examples

The following is sample output from the show tarp tid-cache command:

router# show tarp tid-cache

TID ('*' : static; & : local)               NSAP

* shashi                       49.0001.6666.6666.6666.00

& router                       49.0001.3333.3333.3333.00

* sonali                       49.0001.7777.7777.7777.00

  artemis                      49.0001.1111.1111.1111.00

The following is sample output from the show tarp tid-cache detail command:

router# show tarp tid-cache detail

TID ('*': static; &: local)               NSAP

& router                       49.0001.3333.3333.3333.00

 Expiration time: NONE

Table 54 describes the fields shown in the displays.

Table 54 show tarp tid-cache Field Descriptions 

Field	Description
TID	Target identifier assigned to the TID cache entry. Static entries are flagged with an asterisk (*). The local entry is flagged with an ampersand (&).
NSAP	NSAP address of the TID cache entry.
*	An asterisk (*) indicates that the entry in the TID cache is static (that is, you have created an entry in the TID cache with the tarp map command.
&	An ampersand (&) indicates that the entry in the TID cache is the local entry (that is, the router to which you are connected).
Expiration time	Amount of time the entry remains in the TID cache. When this time expires, the entry is removed from the TID cache. Only dynamic entries have an expiration time. The local entry indicated by an ampersand (&) and static entries indicated by an asterisk (*) are not removed from the TID cache.

Related Commands

Command	Description
clear tarp tid-table	Clears the dynamically created TARP TID-to-NSAP address mapping entries stored in TID cache.
tarp cache-timer	Specifies the length of time that a dynamically created TARP entry remains in the TID cache.
tarp map	Enters a TID-to-NSAP static route in the TID cache.
tarp tid	Assigns a TID to the router.

show tarp traffic

To display statistics about TARP PDUs since the last time the counters were cleared, use the show tarp traffic command in EXEC mode.

show tarp traffic

Syntax Description

This command has no arguments or keywords.

Command Modes

EXEC

Command History

Release	Modification
11.1	This command was introduced.

Examples

The following is sample output from the show tarp traffic command:

router# show tarp traffic

TARP counters:

        Packets output: 11, Input: 5

        Hdr syntax: 0

        No memory: 0, Invalid packet: 0 

        Lifetime exceeded: 0 

Table 55 describes the fields shown in the display.

Table 55 show tarp traffic Field Descriptions

Field	Description
Packets output	Indicates the number of PDUs that this router has originated.
Input	Indicates the number of PDUs that this router has received.
Hdr syntax	Number of PDUs with bad header information.
No memory	Number of times a request for memory failed (because of insufficient memory).
Invalid packets	Number of received PDUs that contained invalid information.
Lifetime exceeded	Number of received PDUs with zero lifetime.

Related Commands

Command	Description
clear tarp counters	Clears all TARP counters that are displayed with the show tarp traffic command.

tarp allow-caching

To re-enable the storage of TID-to-NSAP address mapping in the TID cache, use the tarp allow-caching command in global configuration mode. To disable this function and clear the TID cache, use the no form of this command.

tarp allow-caching

no tarp allow-caching

Syntax Description

This command has no arguments or keywords.

Defaults

Enabled

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

By default, storing TID-to-network (NSAP) address mapping in cache is enabled unless you specifically disable the capability with the no tarp allow-caching command. If you disable this capability, you must use the tarp allow-caching command to re-enable storage of TID-to-network address mapping in cache. After re-enabling this capability, any previously cleared local entry and all static entries are restored.

Examples

The following example disables storage of TID-to-NSAP address mapping in cache on the router:

no tarp allow-caching

Related Commands

Command	Description
clear tarp tid-table	Clears the dynamically created TARP TID-to-NSAP address mapping entries stored in TID cache.
show tarp map	Lists all static entries in the TID cache that were configured with the tarp map command.
show tarp tid-cache	Displays information about the entries in the TID cache.
tarp cache-timer	Specifies the length of time that a dynamically created TARP entry remains in the TID cache.
tarp map	Enters a TID-to-NSAP static route in the TID cache.

tarp arp-request-timer

To set the timeout for TARP Type 5 PDUs, use the tarp arp-request-timer command in global configuration mode. To set the timeout to the default value, use the no form of this command.

tarp arp-request-timer seconds

no tarp arp-request-timer

Syntax Description

seconds

Number of seconds that the router will wait for a response from a TARP Type 5 PDU. The range is from 0 to 3600 seconds. The default is 40 seconds.

Defaults

40 seconds

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

You may want to increase the time if your network has a slow link or there are long delay times on the link.

TARP Type 5 PDUs are sent by the tarp query command to determine a TID that corresponds to a particular NSAP.

Examples

The following example sets the timeout for TARP Type 5 PDUs to 60 seconds (one minute):

tarp arp-request-timer 60

Related Commands

Command	Description
tarp lifetime	Specifies the lifetime for locally generated TARP PDUs based on the number of hops.
tarp query	Determines a TID corresponding to a specific NSAP address.

tarp blacklist-adjacency

To blacklist the specified router so that the router does not receive TARP PDUs propagated by this router, use the tarp blacklist-adjacency command in global configuration mode. To remove the specified router from the blacklist so that the router can once again receive propagated TARP PDUs, use the no form of this command.

tarp blacklist-adjacency nsap

no tarp blacklist-adjacency nsap

Syntax Description

nsap	NSAP address that cannot receive TARP PDUs. Use the full NSAP address.

Defaults

All hosts receive propagated TARP PDUs.

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

A TARP router propagates PDUs to all its TARP adjacencies (both dynamic and static). Use the tarp blacklist-adjacency command to bypass hosts that may not have TARP running or to bypass hosts to which you do not want to propagate TARP PDUs.

Examples

The following example specifies that the router 49.0001.0000.0c00.1111.1234.00 will not receive propagated TARP PDUs:

tarp blacklist-adjacency 49.0001.0000.0c00.1111.1234.00

Related Commands

Command	Description
show tarp blacklisted-adjacencies	Lists all blacklisted adjacencies (to which this router will not propagate TARP PDUs) by the tarp blacklist-adjacency command.

tarp cache-timer

To specify the length of time that a dynamically created TARP entry remains in the TID cache, use the tarp cache-timer command in global configuration mode. To set the timer to the default value, use the no form of this command.

tarp cache-timer seconds

no tarp cache-timer

Syntax Description

seconds

Number of seconds an entry remains in the TID cache. The range is 30 to 86,400 seconds. The default is 3,600 seconds (one hour).

Defaults

3,600 seconds

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

Static entries (those created with the tarp map command) remain in the TID cache unless cleared by the no tarp map command.

If entries frequently change, you may want to use a shorter time period. If entries are stable, you may want to use a longer time period.

Examples

The following example limits the time an entry remains in the TID cache to 1,800 seconds (30 minutes):

tarp cache-timer 1800

Related Commands

Command	Description
clear tarp tid-table	Clears the dynamically created TARP TID-to-NSAP address mapping entries stored in TID cache.
show tarp tid-cache	Displays information about the entries in the TID cache.

tarp enable

To enable the TARP on an interface, use the tarp enable command in interface configuration mode. To disable TARP on a particular interface, use the no form of this command.

tarp enable

no tarp enable

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

Enabling TARP allows the interface to request and respond to TARP PDUs. TARP PDUs are identified by a unique N-selector in the NSAP address. You must also have the TARP process running on the router by using the tarp run command.

Examples

The following example enables TARP on Ethernet interface 0:

interface ethernet 0 
 tarp enable

Related Commands

Command	Description
show tarp interface	Lists all interfaces that have TARP enabled.
tarp nselector-type	Specifies the N-selector to be used in CLNP PDUs to indicate that the packet is a TARP.
tarp propagate	Reenables propagation of TARP PDUs on an interface.
tarp run	Starts the TARP process on the router.

tarp global-propagate

To re-enable the capability to propagate TARP PDUs globally, use the tarp global-propagate command in global configuration mode. To disable global propagation of TARP PDUs, use the no form of this command.

tarp global-propagate

no tarp global-propagate

Syntax Description

This command has no arguments or keywords.

Defaults

Enabled

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

TARP PDUs are globally propagated to all TARP neighbors by default unless you specifically disable the capability with the no tarp global-propagate command. If you disable this capability, you must use the tarp global-propagate command to re-enable global purgation of TARP PDUs.

TARP PDUs are propagated on all interfaces by default unless you specifically disable the capability on a specific interface with the no tarp propagate command.

---

Note The no tarp global-propagate command disables propagation of TARP PDUs on the router (and thus on all interfaces).

---

Examples

The following example disables global propagation of TARP PDUs on this router:

no tarp global-propagate

Related Commands

Command	Description
tarp propagate	Reenables propagation of TARP PDUs on an interface.

tarp ldb-timer

To specify the length of time that a system ID-to-sequence number mapping entry remains in the loop-detection buffer table, use the tarp ldb-timer command in global configuration mode. To set the timer to the default value, use the no form of this command.

tarp ldb-timer seconds

no tarp ldb-timer

Syntax Description

seconds

Number of seconds that a system ID-to-sequence number mapping entry remains in the loop-detection buffer table. The range is 0 to 86,400 seconds. The default is 300 seconds.

Defaults

300 seconds

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

The loop-detection buffer table prevents TARP PDUs from looping.

Examples

The following example limits the time an entry remains in the loop-detection buffer table to 600 seconds (10 minutes):

tarp ldb-timer 600

Related Commands

Command	Description
clear tarp ldb-table	Clears the system ID-to-sequence number mapping entries stored in the TARP loop-detection buffer table.
show tarp ldb	Displays the contents of the loop-detection buffer table.
tarp lifetime	Specifies the lifetime for locally generated TARP PDUs based on the number of hops.

tarp lifetime

To specify the lifetime for locally generated TARP PDUs based on the number of hops, use the tarp lifetime command in global configuration mode. To set the PDU lifetime to the default value, use the no form of this command.

tarp lifetime hops

no tarp lifetime

Syntax Description

hops	Number of hosts that a PDU can traverse before it is discarded. Each router represents one hop. The range is 0 to 65535 hops. The default is 100 hops.

Defaults

100 hops

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

The number of hops specified is decremented after every hop. A PDU with a lifetime of zero is discarded.

Examples

The following example specifies that the TARP PDU can traverse 150 hosts before it is discarded:

tarp lifetime 150

Related Commands

Command	Description
tarp arp-request-timer	Sets the timeout for TARP Type 5 PDUs.
tarp ldb-timer	Specifies the length of time that a system ID-to-sequence number mapping entry remains in the loop-detection buffer table.

tarp map

To enter a TID-to-NSAP static route in the TID cache, use the tarp map command in global configuration mode. To remove a static map entry from the TID cache, use the no form of this command.

tarp map tid nsap

no tarp map tid nsap

Syntax Description

tid	Target identifier to be mapped to the specified NSAP. Alphanumeric string up to 255 characters.
nsap	NSAP address to map to the specified TID. Use the full NSAP address.

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

Use the tarp map command to map multiple NSAP addresses on a router. For example, using the tarp resolve to get the NSAP for a known TID will always return the first NSAP address. If the router has multiple NSAP addresses, you can use the tarp map command to map the TID to multiple NSAP addresses. If a router has NSAP addresses 1, 2, 3, the tarp resolve command will always return NSAP address 1. Use the tarp map command to map the router to NSAP addresses 2 and 3 so the tarp query command will return the TID corresponding to the other NSAP addresses.

Examples

The following example maps the NSAP address 49.0001.000.1111.1111.1234.00 to TID SJ1:

tarp map sj1 49.0001.0000.1111.1111.1234.00

Related Commands

Command	Description
clear tarp tid-table	Clears the dynamically created TARP TID-to-NSAP address mapping entries stored in TID cache.
show tarp map	Lists all static entries in the TID cache that were configured with the tarp map command.
tarp query	Determines a TID corresponding to a specific NSAP address.
tarp resolve	Determines an NSAP address corresponding to a specified TID.

tarp nselector-type

To specify the N-selector to be used in CLNP PDUs to indicate that the packet is a TARP, use the tarp nselector-type command in global configuration mode. To set the N-selector to the default value, use the no form of this command.

tarp nselector-type hex-digit

no tarp nselector-type

Syntax Description

hex-digit

Digit in hexadecimal format to be used to identify TARP PDUs. The default is AF.

Defaults

AF

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

This feature provides flexibility in using the N-selector field to indicate TARP PDUs. The N-selector must be the same on all hosts running the TARP process.

Examples

The following example changes the N-selector used in CLNP PDUs to BC:

tarp nselector-type BC

Related Commands

Command	Description
show tarp	Displays all global TARP parameters.

tarp originate

To re-enable the router to originate TARP PDUs, use the tarp originate command in global configuration mode. To disable the capability to originate TARP PDUs, use the no form of this command.

tarp originate

no tarp originate

Syntax Description

This command has no arguments or keywords.

Defaults

Enabled

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

Origination of TARP PDUs is enabled by default unless you specifically disable the capability with the no tarp originate command. If you disable this capability, you must use the tarp originate command to re-enable origination of TARP PDUs.

Examples

The following example disables the origination of TARP PDUs on this router:

no tarp originate

Related Commands

Command	Description
show tarp	Displays all global TARP parameters.

tarp post-t2-response-timer

To specify the length of time that a router waits for a response to a Type 2 PDU after the default timer expires, use the tarp post-t2-response-timer command in global configuration mode. To set the timer to the default value, use the no form of this command.

tarp post-t2-response-timer seconds

no tarp post-t2-response-timer

Syntax Description

seconds

Number of seconds that the router will wait for a response for a Type 2 PDU after the default timer has expired. The range is 0 to 3,600 seconds. The default is 15 seconds.

Defaults

15 seconds

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

A Type 1 PDU is sent to all Level 1 (IS-IS and ES-IS) neighbors when a router has a TID for which it has no matching NSAP information. If no response is received within the specified timeout period, a Type 2 PDU is sent to all Level 1 and Level 2 neighbors. If no response is received within the specified timeout period, additional time is allocated based on the number specified in the tarp post-t2-response-timer command.

Examples

The following example sets the additional time to wait for a response from a Type 2 PDU to 60 seconds:

tarp post-t2-response-timer 60

Related Commands

Command	Description
tarp t2-response-timer	Specifies the length of time the router will wait for a response from a Type 2 PDU.

tarp propagate

To reenable propagation of TARP PDUs on an interface, use the tarp propagate command in interface configuration mode. To disable propagation of TARP PDUs on one or more interfaces, use the no form of this command.

tarp propagate [all | message-type {unknowns | type-number} [type-number] [type-number]]

no tarp propagate [all | message-type {unknowns | type-number} [type-number] [type-number]]

Syntax Description

all	(Optional) Specifies all TARP PDUs.
message-type unknowns type-number	(Optional) Specifies only type-number broadcast PDUs. The unknowns keyword specifies unknown TARP packets that are not of the standard types 1 through 5. Valid values are 1, 2, and 4. You may enter more than one value for the type-number argument.

Defaults

Enabled

Command Modes

Interface configuration

Command History

Release	Modification
11.1	This command was introduced.
12.0	The following keywords and arguments were added: •all •message-type type-number
12.1(8)	The unknowns keyword was added.

Usage Guidelines

Pressing Return or Enter after tarp propagate is the same as typing the keyword all.

TARP PDUs are propagated on all interfaces by default unless you specifically disable the capability on a specific interface with the no tarp propagate command. The TARP PDU broadcast types 1, 2, and 4 can generate unnecessary traffic across the network, and some users may prefer to disable the propagation of the TARP PDUs. If you disable this capability, you must use the tarp propagate command to reenable propagation of TARP PDUs. Enabling propagation of TARP PDUs allows the interface to propagate PDUs to all neighbors on this interface. TARP PDUs are identified by a unique N-selector in the NSAP.

The current TARP standard specifies that if a TARP packet of an unknown type—any type other than the standard types 1 through 5—is received by an intermediate system, it should be propagated. Unknown TARP packets may be received from the equipment of other vendors.

To disable the propagation of unknown TARP packets, use the unknowns keyword before any values that are entered for the type-number argument:

no tarp propagate message-type unknowns 1 4

---

Note The no tarp global-propagate command disables propagation of TARP PDUs on the router (and, thus, on all interfaces).

---

Examples

The following example starts the TARP process on the router and enables TARP propagation on Ethernet interface 0:

interface ethernet 0 
 tarp propagate

Related Commands

Command	Description
show tarp interface	Lists all interfaces that have TARP enabled.
tarp enable	Enables the TARP on an interface.
tarp global-propagate	Reenables the capability to propagate TARP PDUs globally.
tarp nselector-type	Specifies the N-selector to be used in CLNP PDUs to indicate that the packet is a TARP.
tarp run	Starts the TARP process on the router.

tarp protocol-type

To specify the network protocol type to be used in outgoing TARP PDUs, use the tarp protocol-type command in global configuration mode. To set the protocol type to the default value, use the no form of this command.

tarp protocol-type hex-digit

no tarp protocol-type

Syntax Description

hex-digit

Digit in hexadecimal format to be used to identify the protocol used in outgoing TARP PDUs. The default is FE (for CLNP).

Defaults

FE

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

Only FE is supported.

Examples

The following example shows the tarp network protocol-type changed from the default of FE to AO:

tarp protocol-type ao

Related Commands

Command	Description
show tarp	Displays all global TARP parameters.

tarp query

To a specific NSAP address, use the tarp query command in EXEC mode to determine a corresponding TID entry.

tarp query nsap

Syntax Description

nsap	NSAP address that you want the TID for. Use the full NSAP address.

Command Modes

EXEC

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

If there is a TID entry in the local TID cache, the requested information is displayed.

If there is no TID entry in the local TID cache, a TARP Type 5 PDU is sent to the specified NSAP address. Because the NSAP address is specified, the PDU is unicast to the particular NSAP address. If a response is received (in the form of a Type 3 PDU), the local TID cache is updated and the requested information is displayed.

The length of time that the router will wait for a response to a Type 5 PDU is controlled by the tarp arp-request-timer command.

Examples

The following is sample output from the tarp query command:

router# tarp query 49.0001.3333.3333.3333.00

Type escape sequence to abort.

Sending TARP type 5 PDU, timeout 40 seconds...

 TID corresponding to NET 49.0001.3333.3333.3333.00 is cerd

Table 56 describes the fields shown in the display.

Table 56 tarp query Field Descriptions

Field	Description
Sending TARP type 5 PDU	PDU requesting the TID of the specified NSAP.
Timeout...	Number of seconds the router will wait for a response from the Type 5 PDU. The timeout is set by the tarp arp-request-timer command.
TID corresponding to... is...	Indicates the TID for the specified NSAP address.

Related Commands

Command	Description
show tarp	Displays all global TARP parameters.
tarp arp-request-timer	Sets the timeout for TARP Type 5 PDUs.

tarp resolve

To determine an NSAP address corresponding to a specified TID, use the tarp resolve command in EXEC mode.

tarp resolve tid [1 | 2]

Syntax Description

tid	Target identifier to be mapped to the specified NSAP. Alphanumeric string up to 255 characters.
1	(Optional) Send a Type 1 PDU. The default is a Type 1 PDU. If a response is not received before the timeout period, a Type 2 PDU is sent.
2	(Optional) Send only Type 2 PDU.

Command Modes

EXEC

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

If there is an NSAP entry in the local TID cache, the requested information is displayed.

If there is no NSAP entry in the local TID cache, a TARP Type 1 or Type 2 PDU is sent out. By default a Type 1 PUD is sent. A Type 1 PDU is sent to all Level 1 (IS-IS and ES-IS) neighbors. If a response is received (in the form of a Type 3 PDU), the local TID cache is updated and the requested information is displayed.

If a response from the Type 1 PDU is not received within the timeout period, a Type 2 PDU is sent to all Level 1 and Level 2 neighbors. If a response is received (in the form of a Type 3 PDU), the local TID cache is updated and the requested information is displayed.

The length of time that the router will wait for a response to a Type 1 PDU is controlled by the tarp t1-response-timer command. The length of time that the router waits for a response to a Type 2 PDU is controlled by the tarp t2-response-timer command and the tarp-post-t2-response-timer command.

Examples

The following is sample output from the tarp resolve command:

router# tarp resolve artemis

Type escape sequence to abort.

Sending TARP type 1 PDU, timeout 15 seconds...

 NET corresponding to TID artemis is 49.0001.1111.1111.1111.00

Table 57 describes the fields shown in the display.

Table 57 tarp resolve Field Descriptions

Field	Description
Sending TARP type 1 PDU	PDU requesting the NSAP of the specified TID.
timeout...	Number of seconds the router will wait for a response from the Type 1 PDU. The timeout is set by the tarp t1-response-timer command.
NET corresponding to... is...	Indicates the NSAP address (in this case, 49.0001.1111.1111.1111.00) for the specified TID.

Related Commands

Command	Description
tarp map	Enters a TID-to-NSAP static route in the TID cache.
tarp post-t2-response-timer	Specifies the length of time that a router waits for a response to a Type 2 PDU after the default timer expires.
tarp t1-response-timer	Specifies the length of time the router will wait for a response from a Type 1 PDU.
tarp t2-response-timer	Specifies the length of time the router will wait for a response from a Type 2 PDU.

tarp route-static

To configure a static TARP adjacency, use the tarp route-static command in global configuration mode. To remove a static TARP adjacency from the TARP queue, use the no form of this command .

tarp route-static nsap [all | message-type {unknowns | type-number} [type-number] [type-number]]

no tarp route-static nsap [all | message-type {unknowns | type-number} [type-number] [type-number]]

Syntax Description

nsap	NSAP address to create a static TARP adjacency. Use the full NSAP address.
all	(Optional) Specifies all TARP PDUs.
message-type unknowns type-number	(Optional) Specifies only type-number broadcast PDUs. The unknowns keyword specifies unknown TARP packets that are not of the standard types 1 through 5. Valid values are 1, 2, and 4. You may enter more than one value for the type-number argument.

Defaults

None

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.
12.0	The following keywords and arguments were added: •all •message-type type-number
12.1(8)	The unknowns keyword was added.

Usage Guidelines

Pressing Return or Enter after tarp route-static is the same as typing the keyword all.

A TARP router propagates PDUs to all its adjacencies and static TARP adjacencies.

If a router is not running TARP, the router discards TARP PDUs rather than propagating the PDUs to all its adjacencies. To allow propagation of the PDU to hosts that are "beyond" a non-TARP router, you must use the tarp route-static command to ensure that the hosts receive PDUs. The tarp route-static command allows TARP PDUs to "tunnel" through hosts that are not running TARP. The current TARP standard specifies that if a TARP packet of an unknown type—any type other than the standard types 1 through 5—is received by an intermediate system, it should be propagated.Unknown TARP packets may be received from the equipment of other vendors.

To allow the unknown packet types to "tunnel" through hosts that are not running TARP, use the keyword preceding any values entered for the type-number argument:

tarp route-static nsap message-type unknowns 1 4

The specified router, as identified by the NSAP address, is stored in a TARP static adjacencies queue.

Use the tarp blacklist-adjacency command to prevent sending TARP PDUs directly to hosts that are not running TARP.

Examples

The following example adds 49.0001.0000.0c00.1111.1234.00 as a static TARP adjacency to the TARP queue:

tarp route-static 49.0001.0000.0c00.1111.1234.00

Related Commands

Command	Description
show tarp static-adjacencies	Lists all static TARP adjacencies that are configured with the tarp route-static command.
tarp blacklist-adjacency	Blacklists the specified router so that the router does not receive TARP PDUs propagated by this router.

tarp run

To start the TARP process on the router, use the tarp run command in global configuration mode. To stop the TARP process, use the no form of this command.

tarp run

no tarp run

Syntax Description

This command has no arguments or keywords.

Defaults

No TARP process (unless configured to start in NVRAM).

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

You must also enable TARP on the individual interfaces by using the tarp enable command.

Examples

The following example starts the TARP process on the router:

tarp run

Related Commands

Command	Description
tarp enable	Enables the TARP on an interface.
tarp propagate	Reenables propagation of TARP PDUs on an interface.

tarp sequence-number

To specify the sequence number to be used in the next outgoing TARP PDU, use the tarp sequence-number command in global configuration mode. To return to the default value, use the no form of this command.

tarp sequence-number number

no tarp sequence-number number

Syntax Description

number

Number from 0 to 65535 that will be used as the sequence number in the next outgoing PDU. The default is zero.

Defaults

Zero

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

The sequence number lets the router determine if information received in the PDU is newer than the last information received. You may want to increase the sequence number to ensure that other hosts update their entries in TID cache.

Examples

The following example causes a sequence number of 10 to be assigned to the next TARP PDU:

tarp sequence-number 10

Related Commands

Command	Description
show tarp	Displays all global TARP parameters.
show tarp ldb	Displays the contents of the loop-detection buffer table.

tarp t1-response-timer

To specify the length of time the router will wait for a response from a Type 1 PDU, use the tarp t1-response-timer command in global configuration mode. To set the timer to the default value, use the no form of this command.

tarp t1-response-timer seconds

no tarp t1-response-timer

Syntax Description

seconds

Number of seconds that the router will wait to receive a response from a Type 1 PDU. The range is 0 to 3600 seconds. The default is 15 seconds.

Defaults

15 seconds

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

A Type 1 PDU is sent to all Level 1 (IS-IS and ES-IS) neighbors when a router has a TID for which it has no matching NSAP information. If no response is received within the timeout period (specified by the tarp t1-response-timer command), a Type 2 PDU is sent to all Level 2 neighbors.

Examples

The following example sets the timeout period for a Type 1 PDU to 60 seconds:

tarp t1-response-timer 60

Related Commands

Command	Description
tarp t2-response-timer	Specifies the length of time the router will wait for a response from a Type 2 PDU.

tarp t2-response-timer

To specify the length of time the router will wait for a response from a Type 2 PDU, use the tarp t2-response-timer command in global configuration mode. To set the timer to the default value, use the no form of this command.

tarp t2-response-timer seconds

no tarp t2-response-timer

Syntax Description

seconds

Number of seconds that the router will wait to receive a response from a Type 2 PDU. The range is 0 to 3600 seconds. The default is 25 seconds.

Defaults

25 seconds

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

A Type 1 PDU is sent to all Level 1 (IS-IS and ES-IS) neighbors when a router has a TID for which it has no matching NSAP information. If no response is received within the timeout period (specified by the tarp t1-response-timer command), a Type 2 PDU is sent to all Level 2 neighbors. If no response is received within the timeout period (specified by the tarp t2-response-timer command), additional time can be allocated by using the tarp post-t2-response-timer command.

Examples

The following example sets the timeout period for a Type 2 PDU to 60 seconds:

tarp t2-response-timer 60

Related Commands

Command	Description
tarp post-t2-response-timer	Specifies the length of time that a router waits for a response to a Type 2 PDU after the default timer expires.
tarp t1-response-timer	Specifies the length of time the router will wait for a response from a Type 1 PDU.

tarp tid

To assign a TID to the router, use the tarp tid command in global configuration mode. To remove the TID from the router, use the no form of this command.

tarp tid tid

no tarp tid tid

Syntax Description

tid	Target identifier to be used by this router. Alphanumeric string up to 255 characters.

Defaults

None

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

All hosts using TARP must have a unique TID assigned.

Examples

The following example assigns the TID SJ3 to the router:

tarp tid sj3

Related Commands

Command	Description
show tarp	Displays all global TARP parameters.
show tarp host	Displays information about a specific TARP router stored in the local TID cache.
show tarp tid-cache	Displays information about the entries in the TID cache.

tarp urc

To set the update remote cache bit in all subsequent outgoing PDUs, use the tarp urc command in global configuration mode. To set the update remote cache bit to the default value, use the no form of this command.

tarp urc {0 | 1}

no tarp urc

Syntax Description

0	Sets the update remote cache bit to 0, which is the default value. When the bit is zero, the receiver's PDU will update its TID cache entry.
1	Sets the update remote cache bit to 1. When the bit is 1, the receiver's TID cache is not updated.

Defaults

The default value is 0.

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

If you do not specify either 0 or 1, the default value 0 is used.

Examples

The following example sets the update remote cache bit in the outgoing PDU to 1, so the cache at the receiver's end is not updated:

tarp urc 1

Related Commands

Command	Description
show tarp	Displays all global TARP parameters.

timers basic (ISO CLNS)

To configure ISO IGRP timers, use the timers basic command in router configuration mode. To restore the default values, use the timers basic router configuration command, use the no form of this command.

timers basic update-interval holddown-interval invalid-interval

no timers basic update-interval holddown-interval invalid-interval

Syntax Description

update-interval	Time, in seconds, between the sending of routing updates. The default value is 90 seconds.
holddown-interval	Time, in seconds, a system or area router is kept in holddown state, during which routing information regarding better paths is suppressed. (A router enters into a holddown state when an update packet is received that indicates the route is unreachable. The route is marked inaccessible and advertised as unreachable. However, the route is still used for forwarding packets.) When the holddown interval expires, routes advertised by other sources are accepted and the route is no longer inaccessible. The default value is 145 seconds.
invalid-interval	Time, in seconds, that a route remains in the routing table after it has been determined that it is not reachable. After that length of time, the route is removed from the routing table. The default value is 135 seconds.

Defaults

update-interval = 90 seconds
holddown-interval = 145 seconds
invalid-interval = 135 seconds

Command Modes

Router configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Because the ISO IGRP routing protocol executes a distributed, asynchronous routing algorithm, it is important that these timers be the same for all routers in the network.

Examples

In the following example, updates are broadcast every 60 seconds. When an update packet is received that indicates the router is unreachable, the router will be in holddown state for 100 seconds before once more becoming accessible. If a router is not heard from in 130 seconds, the route is removed from the routing table.

router iso-igrp

 timers basic 60 100 130

which-route

If you want to know which next-hop router will be used or if you have multiple processes running and want to troubleshoot your configuration, use the which-route command in EXEC mode. This command displays the routing table in which the specified CLNS destination is found.

which-route {nsap-address | clns-name}

Syntax Description

nsap-address	CLNS destination network address.
clns-name	Destination host name.

Command Modes

EXEC

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Route information can reside in the following tables:

•IS-IS Level 1 routing table

•ISO IGRP system-id or area routing table

•Prefix routing table (IS-IS Level 2 routes, ISO IGRP domain routes, and static routes)

•Adjacency database

Examples

The following example shows that destination information for router gray is found in the IS-IS Level 1 routing table. The destination is on the local system.

gray# which-route gray

Route look-up for destination 39.0001.0000.0c00.bda8.00, GRAY

 Found route in IS-IS level-1 routing table - destination is local 

The following example shows that destination information for NSAP address 49.0001.0000.0c00.bda8.00 is found in the ISO IGRP Level 1 routing table. The destination is on the local system.

gray# which-route 49.0001.0000.0c00.bda8.00

Route look-up for destination 49.0001.0000.0c00.bda8.00

 Found route in ISO IGRP routing table - destination is local

The following example shows that destination information for router green is found in the IS-IS Level 1 routing table. The destination is not on the local system.

gray# which-route green

Route look-up for destination 39.0001.0000.0c00.7f06.00, GREEN

 Found route in IS-IS level-1 routing table

Adjacency entry used:

System Id       SNPA             Interface   State Holdtime Type Protocol

GREEN           0000.0c00.2d55   Ethernet0   Up     91        L1L2  IS-IS

  Area Address(es): 39.0001

Table 58 describes the display fields in the adjacency entry used to reach system green.

Table 58 which-route Field Descriptions

Field	Description
System ID	Six-byte value that identifies a system in an area. A name is displayed in this field if one has been assigned with the clns host global configuration command.
SNPA	SNPA data link address.
Interface	Interface from which system information was learned.
State	State of the ES or IS. Possible values are as follows: Init—The system is an IS and is waiting for an IS-IS hello message. The neighbor to the IS-IS is not adjacent. Up—The ES or IS is reachable.
Holdtime	Number of seconds for which the information is valid.
Type	Adjacency type. Possible values are as follows: ES—An end-system adjacency that is either discovered by the ES-IS protocol or statically configured. IS—A router adjacency that is either discovered by the IS-IS protocol or is statically configured. L1—A router adjacency for Level 1 routing only. L1L2—A router adjacency for Level 1 and Level 2 routing. L2—A router adjacency for Level 2 only.
Protocol	Protocol through which the adjacency was learned. Valid protocol sources are ES-IS, IS-IS, ISO IGRP, and Static.

The following example shows that destination information for NSAP address 49.0001.1111.1111.1111.00 is found in the ISO IGRP routing table. Table 58 describes the display fields in the adjacency entry used to reach NSAP address 49.0001.1111.1111.1111.00.

gray# which-route 49.0001.1111.1111.1111.00

Route look-up for destination 49.0001.1111.1111.1111.00

 Found route in ISO IGRP routing table

Adjacency entry used:

System Id       SNPA             Interface   State Holdtime Type Protocol

1111.1111.1111 0000.0c01.151d   Ethernet1   Up     38        L1L2 ISO IGRP

 Area Address(es): 49.0001

The following example indicates that the specified address is not found in a routing table:

gray# which-route 47.0003.0000.0000.0000.00

Route look-up for destination 47.0003.0000.0000.0000.00

 Route not found

The following example indicates that the specified NSAP address was found in the CLNS prefix routing table. This information is followed by the route entry used to reach NSAP address 49.0003.0000.0000.0000.00.

gray# which-route 49.0003.0000.0000.0000.00

Route look-up for destination 49.0003.0000.0000.0000.00

 Found route in CLNS prefix routing table

Route entry used:

49 [10/0]

  via 1111.1111.1111, Ethernet1, Static

Related Commands

Command	Description
clns host	Defines a name-to-NSAP mapping that can then be used with commands requiring NSAPs.