- Plesk for Linux
Cannot setup slave DNS server using Slave DNS extension, if point to exclamation mark it displays the following error:
CONFIG_TEXT: Error code 1: rndc: connect failed: 203.0.113.2#953: timed out
'nmap' utility reports that the port is filtered.
# nmap -p953 203.0.113.2
PORT STATE SERVICE
953/tcp filtered rndc
Port 953 is required by
rndc tool. The connection from master DNS server to slave DNS server via port 953 is not available.
Check firewall settings and make sure that access from the master DNS server to the slave DNS via port 953.