IBM MQ can restrict the client which connect to the QMGR from another QMGR or from a client application by using the SSLPEER arrtribute on the channel ( Channel can be a SVRCONN or SDR or RCVR or Cluster sender and Receiver channels)
SSLPEER validate the DN of the certitificate that the client or QMGR is trying to connect over the channel.
QMGR Chanel may contain SSLPEER value which can be full Subject of the certificate or a partial matching values with Wildcard (*) or a partial values.
SSLPEER(‘CN=ABC.COM, OU=ABC*’)
the application which tries to connect with the above cert will be allowed by QMGR
if it is bettween QMGR1 to QMGR2 . SSLPEER should be configured in opposite way like QMGR1 certificate details should in SSLPEER of channel with in QMGR2 and viceversa.
SSLPEER Missmatch error will get if the confiugreation are not matched with SSLPeer name that is sent by the client.
ping channe(CHLNAME)
or look for the MQ logs
if the SSLPeer not matches it will through the error on the logs.
SDR channel will be in Retrying stage in such case.