Internal error in communication channel.
Already have CSCsu84143 installed.
I have a multiserver environment with 2 servers (DCR master = CM & IPM; DCR slave = RME & DFM)
I always recommend using short hostnames for certs and multi-server trust. However, if you must use FQDN, then the cert must use the FQDN, and the slave needs to be registered to the server using FQDN.
In the case of my local servers, the IP had been changed while keeping the servers' hostnames the same. Only problem was, DNS was pointing the current hostname to the old IP addresses. The fix was to change the servers' hostnames to match the new DNS entries for the corresponding IP addresses. I then regenerated the certs for the new short hostnames, and re-established the peer relationship using the short hostnames. Everything has worked fine since.