So, it’s a URL encoding issue. I did some research online, and found that UCS Director isn’t encoding the square braces natively, so it generates an error.
So this URI API Path - /api/node/mo/topology/pod-1/node-201/sys/phys-[eth1/96]/phys.json
The [ ] need to be encoded manually to this in Hex
Left Square Bracket ("[") 5B
Right Square Bracket ("]") 5D
/api/node/mo/topology/pod-1/node-201/sys/phys-%5Beth1/96%5D/phys.json
Once I replaced the [ with %5B and ] with %5D, UCS Director was able to properly send the API path to ACI and return the correct results.
Jul 14, 2019 18:42:31 CDT ALL ($) = {'totalCount':'1','imdata':[{'ethpmPhysIf':{'attributes':{'accessVlan':'unknown','allowedVlans':'','backplaneMac':'00:42:68:6D:4C:7A','bundleBupId':'1','bundleIndex':'unspecified','cfgAccessVlan':'unknown','cfgNativeVlan':'unknown','childAction':'','currErrIndex':'4294967295','diags':'none','dn':'topology/pod-1/node-201/sys/phys-[eth1/96]/phys','encap':'3','errDisTimerRunning':'no','errVlanStatusHt':'0','errVlans':'','hwBdId':'0','hwResourceId':'0','intfT':'phy','iod':'100','lastErrors':'0','lastLinkStChg':'1969-12-31T19:00:00.000-05:00','media':'2','modTs':'never','monPolDn':'uni/infra/moninfra-default','nativeVlan':'unknown','numOfSI':'0','operBitset':'4','operDceMode':'edge','operDuplex':'full','operEEERxWkTime':'0','operEEEState':'not-applicable','operEEETxWkTime':'0','operErrDisQual':'none','operFecMode':'disable-fec','operFlowCtrl':'0','operMdix':'auto','operMode':'trunk','operModeDetail':'unknown','operPhyEnSt':'unknown','operRouterMac':'00:00:00:00:00:00','operSpeed':'10G','operSt':'down','operStQual':'link-failure','operStQualCode':'0','operVlans':'','osSum':'failed','portCfgWaitFlags':'0','primaryVlan':'vlan-1','resetCtr':'0','siList':'','status':'','txT':'unknown','usage':'discovery','userCfgdFlags':'0','vdcId':'1'}}}]}
Jul 14, 2019 18:42:31 CDT Task #3 (ACI API Test (Execute Generic API)) completed successfully in 0 seconds