Spectrum's Internal_If_Alias attribute does not match the devices actual ifAlias entry for ports

Products

• CA Spectrum

Issue/Introduction

When modeling devices that support Cisco's CatStackApp functionality, the Internal_If_Alias (0x11f82) attribute does not match the devices actual ifAlias (0x11f7e) entry for ports. This is because the Internal_If_Alias attribute was designed to be used internally by Spectrum. The attribute is used as part of an inference handler to keep track of the interface table information. Depending upon the device information, Spectrum may set the Internal_If_Alias to a value that does not match the external ifAlias on the device. This is functioning as designed.

There may be a need to utilize the value of an interfaces ifalias as querying or using the external ifalias attribute (attribute 0x11f7e) in Spectrum, this is very expensive and should not be used. In Spectrum attribute X_ifAlias (0x13224) was added, which is designed to be a copy of the devices external ifalias value. This will allow users to create global collections and searches that use the internal value instead of the external value.

There are a few considerations for this attribute:

• The X_ifAlias(0x13224) attribute will attempt to update on SS startup. If the device is DOWN when the SS starts up, the X_ifAlias(0x13224) may not be in synch with the external ifalias since external ifalias is a read from the device.
  
  
• The X_ifAlias(0x13224) does NOT update when running a model reconfiguration. It only updates at SS startup and by using the update action code of 0x10411 (from CLI) -- this can be scripted or customized into event procedures if need be. See below for details.

Environment

Spectrum 22.x and above

Resolution

Implement an event procedure to run the action code 0x10411.

Many customers will send a device configuration change trap to Spectrum.  When that is sent, you can use action code 0x10411 to re read the ifAlias on the ports.  To do that, add this entry to the $SPECROOT/custom/Events/EventDisp on the SpectroSERVER(s):

 

0x821029 E 0 P "Action( {C CURRENT_MODEL}, {I 66577} )"

After adding that entry, navigate to the VNM - Component Detail - SpectroSERVER Control - Press the Update Event Configuration button

Additional Information

 

Note:  When creating global collection searches for ifAlias, use the X_ifAlias attribute instead.  This will prevent the need for Spectrum to externally query the devices when the search is run.