Symptoms
- FTP service fails to start with the following error:
xinetd[503]: socket creation failed (Address family not supported by protocol (errno = 97)). service = ftp
xinetd[503]: Service ftp failed to start and is deactivated.` - IPv6 support is disabled:
# grep v6 /etc/modprobe.conf
alias ipv6 off
options ipv6 disable=1
# grep -i v6 /etc/sysconfig/network
NETWORKING_IPV6=no
IPV6FORWARDING=yes
Cause
The issue is caused by disabled IPv6 support on the host
Resolution
Connect to the server via SSH and remove the line in /etc/xinetd.d/ftp_psa
as shown in the example below:
service ftp
{
flags = IPv6 <== REMOVE
flags = IPv4 <== ADD
disable = no
socket_type = stream
protocol = tcp
wait = no
user = root
instances = UNLIMITED
server = /usr/sbin/in.proftpd
server_args = -c /etc/proftpd.conf
}
Note: this change could be lost after Plesk upgrade.