TARP > Config
Use the TARP Config subtab to provision the TID Address Resolution protocol. TARP is used when TL1 TIDs must be translated to an NSAP address. During the TID-to-NSAP translation, the TID is first mapped to a NET and then the NSAP is derived from the NET based on the NSAP selector value.
 
Item
Description
TARP PDUs Propagation
If checked (default), TARP Type 1 PDUs received by the node that are not excluded by the loop detection buffer are propagated to other NEs within the Level 1 OSI area. (Type 1 PDUs request a protocol address that matches a target TID within a Level 1 routing area.) The propagation does not occur if the NE is the target of the Type 1 PDU, and PDUs are not propagated to the NE from which the PDU was received. (This parameter is not used when the Node Routing Area (Provisioning > OSI > Main Setup tab) is set to End System.)
TARP PDUs L2 Propagation
(Does not apply to all platforms.) If checked (default), TARP Type 2 PDUs received by the node that are not excluded by the loop detection buffer are propagated to other NEs within the Level 2 OSI areas. (Type 2 PDUs request a protocol address that matches a target TID within a Level 2 routing area.) The propagation occurs if the NE is not the target of the Type 2 PDU, and PDUs are not propagated to the NE from which the PDU was received. (This parameter is only used when the Node Routing Area is provisioned to Intermediate System Level 1/Level 2.)
TARP PDUs Origination
If checked (default), the node performs all TARP origination functions including:
 •
TID to NSAP resolution requests (originate TARP Type 1 and Type 2 PDUs)
 •
NSAP to TID requests (originate Type 5 PDUs)
 •
TARP address changes (originate Type 4 PDUs)
Note
TARP Echo and NSAP to TID is not supported.
TARP Data Cache
If checked (default), the node maintains a TARP data cache (TDC). The TDC is a database of TID to NSAP pairs created from TARP Type 3 PDUs received by the node—TARP 3 PDUs are responses to Type 1 and Type 2 PDUs—and modified by TARP Type 4 PDUs (TID to NSAP updates or corrections). It can also be populated with static entries entered on the TARP > Static TDC tab. (This parameter is only used when the TARP PDUs Origination parameter is enabled.)
L2 TARP Data Cache
(Does not apply to all platforms.) If checked (default), the TIDs and NSAPs of NEs originating Type 2 requests are added to the TDC before the node propagates the requests to other NEs.
Note
This parameter is designed for Intermediate System Level 1/Level 2 nodes that are connected to other Intermediate System Level 1/Level 2 nodes. Enabling the parameter for Intermediate System Level 1 nodes is not recommended.
LDB
If checked (default), enables the TARP loop detection buffer. The LDB prevents TARP PDUs from being sent more than once on the same subnet.
Note
The LDP parameter is not used if the Node Routing Mode is provisioned to End System or the TARP PDUs L1 Propagation parameter is not enabled.
LAN TARP Storm Suppression
If checked (default), enables the TARP storm suppression to prevent redundant TARP PDUs from being propagated across the network.
Send Type 4 PDU on Startup
If checked, a TARP Type 4 PDU is originated during the initial ONS 15454 startup. Type 4 PDUs indicate a TID or NSAP change has occurred at the NE. (The default setting is not enabled.)
Type 4 PDU Delay
Sets the amount of time that will pass before the Type 4 PDU is generated when Send Type 4 PDU on Startup is enabled. 60 seconds is the default. The range is 0 to 255 seconds.
Note
The Send Type 4 PDU on Startup and Type 4 PDU Delay parameters are not used if TARP PDUs Origination is not enabled.
Timers
LDB Entry
Sets the TARP loop detection buffer timer. The LDB buffer time is assigned to each LDB entry for which the TARP sequence number (tar-seq) is zero. The default is 5 minutes. The range is 1 to 10 minutes.
LDB Flush
Sets the frequency period for flushing the LDB. The default is 5 minutes. The range is 0 to 1440 minutes.
T1
Sets the amount of time to wait for response to a Type 1 Request PDU. Type 1 requests seek a specific NE TID within an OSI Level 1 area. 15 seconds is the default. The range is 0 to 3600 seconds.
T2
Sets the amount of time to wait for a Type 2 Request PDU. TARP Type 2 requests seek a specific NE TID value within an OSI Level 1 and Level 2 areas. 25 seconds is the default. The range is 0 to 3600 seconds.
T3
Sets the amount of time to wait for an address resolution request. 40 seconds is the default. The range is 0 to 3600 seconds.
T4
Sets the amount of time to wait for an error recovery. This timer begins after the T2 timer expires without successfully finding the NE TID. 20 seconds is the default. The range is 0 to 3600 seconds.
Apply
Applies changes made to the TARP > Config subtab parameters.
Reset
Cancels any TARP > Config subtab changes and returns the fields to their last-saved settings.
Help
Displays context-sensitive help.

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