Message IST530I or IST1278I received with GUNBIND PENDING or session hangs in PSESEND state

Problem statement

A GUNBIND PENDING message is received at logoff time in a cross-domain environment (if IOPD is specified or defaulted in the VTAM® start options), or the session hangs in PSESEND session termination state.

Common symptoms

Message IST530I or IST1278I:
```
GUNBIND PENDING FROM applname TO LU
```
Message IST530I or IST1278I
```
GUNBIND PENDING FROM VTAM TO LU
```
The session displays PSESEND as the session termination state.

Probable cause

The application did not issue a CLSDST macroinstruction.
The device did not respond to the UNBIND request or returned a response that was incorrect or not valid.
A virtual route between the primary logical unit (PLU) subarea and the secondary logical unit (SLU) subarea is held or blocked.
The network ID defined in the NCP does not match the network ID coded in the VTAM start options.

User response

Enter (on the terminal owning the host) and note the status:
```
D NET,ID=devicename,E
```
If the session termination state is PSESEND, enter:
```
D NET,SESSIONS,SID=sid 
```
(where the SID is that of the PSESEND session in the IST635I message group)
This display will show which session partner is withholding the session end signal to complete the session termination.
- If a SESSEND is needed from the PLU, VTAM is waiting for a CLSDST macroinstruction to be issued.
- If a SESSEND is needed from the SLU, there is usually a problem in a network element, such as the host VTAM, NCP, or SLU.
If the device is remote and hangs in PSESEND session termination state at logoff, start the following trace (in the device-owning host), and trace a logon and logoff:
```
F NET,TRACE,TYPE=BUF,ID=devicename
```
Check the X'15' vector in the SESSST and SESSEND RUs (if they are present) to see if the network ID matches the network ID coded in the VTAM start options.
Enter (on the application-owning host) and note the status:
```
D NET,ID=applname,E
```
This indicates whether other sessions are affected. If the application name has many sessions, this display output can be very large.
```
D NET,ID=devicename,E
```
This indicates whether the session status matches the session status in the device host.
```
D NET,ROUTE,DESTSUB=device_subarea_number,TEST=YES
```
This indicates that a virtual route is held or blocked.
```
D NET,TERM,SID=sid,TYPE=FORCE
```
This may help expedite session termination.
If it is suspected that no CLSDST macroinstruction is being issued, a buffer trace of the application and a VTAM internal trace with MODE=EXT,OPT=API specified may be needed to verify:
- That the application was notified of session termination
- Which exit was scheduled
- What actions or commands were issued (if any) by the application