An MQCONN call was issued from a client to connect to a queue manager but the attempt to allocate a conversation to the remote system failed. Common causes of this reason code are:
  • The listener has not been started on the remote system.
  • The connection name in the client channel definition is incorrect.
  • The network is currently unavailable.
  • A firewall blocking the port, or protocol-specific traffic.
  • The security call initializing the IBM® MQ client is blocked by a security exit on the SVRCONN channel at the server.

Completion code


Programmer response

Examine the client error log for messages explaining the cause of the problem.

[Linux]If you are using a Linux® server, and receiving a 2538 return code when trying to connect to a queue manager, ensure that you check your internal firewall configuration.
  • To diagnose the problem, issue the following commands to temporarily turn off the internal Linux firewall :
    /etc/init.d/iptables save
    /etc/init.d/iptables stop
  • To turn the internal Linux firewall back on, issue the command:
    /etc/init.d/iptables start
  • To permanently turn off the internal Linux firewall, issue the command:
    chkconfig iptables off