On 2/16/22 17:06, William Cole via Nut-upsuser wrote:
Hello All,

I ran telnet on both machines:
   First from the server [235] to the client [236]
   Then from the client [236] to the server [235]

The result in both cases:
   Trying 192.168.1.xxx
   telnet: Unable to connect to remote host: Connection refused.

I am 90% sure that you have a firewall that blocks TCP connections. Many modern linux distros come with a default firewall which blocks all incoming connections or allow a very limited subset of ports, like ssh  ( port 22 ) and web ( port 80 and/or 443 ).

You can do a quick test by running as root ( or via sudo if needed ) one of the following two commands on the server machine:

    iptables -I INPUT -p tcp --dport 3493 -j ACCEPT <==  this will enable access to port TCP/3493

or

    iptables -F <=== this should disable the firewall completely. Note that depending on the distribution that you use, a more civilized way to ( temporary ) disable the firewall exists, for instance in recent Debian/Ubuntu you'd run /ufw disable/ while on CentOS/RHEL you'd use /systemctl stop firewalld ( /with the obvious /ufw enable/ resp /systemctl start firewalld/ to enable the firewall back )

If I am right, once you've allowed the incoming connection, repeating the telnet command should succeed. In this case you must modify the firewall and add a permanent rule to allow the connection.


wolfy
//



_______________________________________________
Nut-upsuser mailing list
[email protected]
https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/nut-upsuser

Reply via email to