The support priest sent me the complete list of recommended PTFs for EE and we were missing three PTFs. I have since confirmed that those were probably the three that we needed because after applying them the systems are again able to communicate using the old protocol.
When I checked I found that the EE list noted above wasn't up to date. I've sent feedback to the keepers of the web site, but as a courtesy I thought I'd post the complete list here as well:
PTF | Release | Cumulative Tape | Modules |
MF40235 | 540 | 7107 | *HPRIP ctlr with exchange ID defined will not vary on and SDLC XID has problem if HPR=*YES. |
MF43629 | 540 | 8305 | *HPRIP ctlr with exchange ID defined will not vary on. |
MF42291 | 540 | 8183 | DLUR and HPRIP controllers go vary on pending after Activate instead of VARIED ON, CPA58D1. MSCP changed to allow DLUR to recover on VTAM deactivate or activate. |
MF42499 | 540 | 8057 | NETWORK ID ALWHPTWR and HPR are *YES, ICF applications fail w/CPF5535, jobs remain in a UNKNOWN state. Sequence of BAD XID network frames case EE to be improperly initialized with invalid controller's values. |
MF42587 | 540 | 8057 | EE HPRIP controller remains in VaryOnPending status with no XID's being sent out. |
MF45692 | 540 | 1000 | EE using HPR and RTP receives timeout error. application joblogs show CPF5355. APPN&SrcSink shows RTPburst timer did not expire AND EE/HPR CONNECTION STALLS AND NO DATA IS SENT |
MF44200 | 540 | 8305 | EE endnode unable to locate a CICS region on ZOS LPAR |
MF43891 | 540 | 8305 | LDLC remains in a reset status, LatePrenegotiation XID does not send a NULL XID on its own. |
MF45851 | 540 | 1000 | HPR config is active, but active connections lock up, When you vary off APPC *HPRIP controllers and vl 07000C1F occurs, the process to activate PTF. An IPL will be needed to reset error condition. AND EE/HPR stops sending data when incoming stream data packet missing |
MF46217 | 540 | 1000 | EE task may block streams on gate before error is sent back |
MF46237 | 540 | 1000 | Vary On HPRIP CTL fails after IPL, XID does not complete |
MF44897 | 545 | 8305 | DLUR and HPRIP controllers go vary on pending after Activate instead of VARIED ON, CPA58D1. MSCP changed to allow DLUR to recover on VTAM deactivate or activate. |
MF45170 | 545 | 9104 | NETWORK ID ALWHPTWR and HPR are *YES, ICF applications fail w/CPF5535, jobs remain in a UNKNOWN state. Sequence of BAD XID network frames case EE to be improperly initialized with invalid controller's values. |
MF44262 | 545 | 8305 | *HPRIP ctlr with exchange ID defined will not vary on. |
MF45881 | 545 | 9104 | HEA fc181X and Virtual Ethernet fc268C lossing data in UDP layer |
MF46122 | 545 | 8305 | NETWORK ID ALWHPTWR and HPR are *YES, ICF applications fail w/ CPF5535 and will now accept retransmitted frames in BIND. |
MF43329 | 545 | 8183 | Partition/system crash with srcB6005121 on vary of EE controller |
MF44072 | 545 | 8183 | EE HPRIP controller remains in VaryOnPending status with no XID's being sent out |
  | 545 | do not order - test status | MF44344 - EE/HPR ICF application fails. CPF5107 E015 unbind received RTP did not check for this error |
MF46366 | 545 | 1000 | Vary On HPRIP CTL fails after IPL, XID does not complete |
MF46218 | 545 | 1000 | EE task may block streams on gate before error is sent back |
MF46063 | 545 | 1000 | APPC using HPR/EE gets RTP timeout |
MF46064 | 545 | 1000 | EE endnode unable to locate a CICS region on ZOS LPAR |