Unable to establish a DLSw circuit
Symptom
A DLSw circuit cannot be correctly established. The display dlsw circuit command output shows that the virtual circuit is not in the CONNECTED state.
Analysis
Many reasons can cause circuit establishment failure.
A TCP connection with the peer end must be successfully established first.
If a TCP connection can be successfully established but circuit establishment fails, the problem is usually caused by abnormal cooperation between the router and the SNA device, most likely from some incorrect SDLC configuration.
Solution
First enable the SDLC debugging, and check whether the SDLC interface can receive/forward frames correctly by executing the display interface command. If the interface cannot receive/forward frames correctly, possible causes are incorrect encoding scheme, baud rate or clock configuration on the interface. Modify the interface configuration of the router or adjust the configuration parameters of the SDLC device.
If frames can be received and forwarded correctly, examine whether the configuration of the PU type is correct. Use the sdlc xid command to configure the XID and change the PU type.
If the PU type is correct, use the display dlsw circuit verbose command to check whether the virtual circuit can enter the CIRCUIT_EST state. If not, the MAC address of the SDLC peer is not correctly configured. Use the sdlc mac-map remote command to modify the configuration parameters.
If the circuit can reach the CIRCUIT_EST state but cannot reach the CONNECTED state, the configuration of the SDLC on the router does not match that of the SNA devices. Check the configuration of the SDLC devices on both sides and the router. For example, check whether the XID (PU2.1) of the SNA device is correctly configured, and whether the XID (PU2.0) of the router is correctly configured. If all these configurations are correct, check whether the SDLC line on the primary SDLC device side (such as the AS/400 or S390) is activated. Sometimes the SDLC line needs to be activated manually.