When listening sockets for some particular port are listed on a rhel-7, only IPv6 sockets are listed on that particular port. But still, IPv4 connections are able to establish, how come? The example below is for a test application acting as a server here, listening on TCP port 3005: # netstat -nlt6 Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address   Foreign Address   State  tcp6  0  0 :::22     :::*     LISTEN  tcp6  0  0 ::1:25     :::*     LISTEN  tcp6  0  0 :::3005     :::*     LISTEN # netstat -nlt4 Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address   Foreign Address   State  tcp  0  0 0.0.0.0:22    0.0.0.0:*    LISTEN  tcp  0  0 127.0.0.1:25   0.0.0.0:*    LISTEN So as can be seen in the example above there is only IPv6 listening socket on the TCP port 3005. But IPv4 TCP clients are still able to establish a connection to this port. # telnet 127.0.0.1 3005 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. # netstat -nt4 Active Internet…