Kerberos not communicating while add Peer between two cluster's for HDFS Replication.
Error msg : peer kdc host is not reachable on port 88 .Please ensure that KDC is up and no firewalls are blocking port 88
Can you check the "/etc/krb5.conf" file present on the host which is showing the error "kdc host is not reachable on port 88" ?
Checks from Client machine:
Then verify what is the hostname for KDC mentioned in this file?
suppose kdc hostname is "kdc.example.com" then check if you are able to access that hhostname & port from the problematic machine?
# telnet kdc.example.com 88 (OR) # nc -v kdc.example.com 88
Also please verify if the "/etc/hosts" file is mapped to correct hostname& port for the kdc.example.com?
# cat /etc/hosts
On the KDC host
Check on the KDC side is the port 88 is listening and iptables/firewall is disabled?
# netstat -tnlpa | grep $PID_Of_KDC # service iptables status # systemctl status firewalld
# telnet kdc.example.com 88 is working (but from CM >> Backup>>Add Peers >> from here it is not working)
# cat /etc/hosts - Mapping was correct
# netstat -tnlpa | grep $PID_Of_KDC
tcp 0 0.0.0.0:88 lISTEN 68214/krb5kdc
# service iptables status
# systemctl status firewalld - Command not found