iptables and NoMachine

[OES1]

 

I have tried to setup NoMachine access remotely on Ubuntu 18 Bionic Beaver across the LAN with an iptables firewall running without success.

I am able to connect to the server over LAN without any firewall just fine. But if I setup the following config in iptables, then the NoMachine server becomes unreachable:

Chain INPUT (policy DROP)

target     prot opt source               destination

ACCEPT     udp  —  192.168.0.0/24       anywhere

ACCEPT     tcp  —  192.168.0.0/24       anywhere

 

Output and forward chain are both empty and set to accept all connections. I was hoping that this configuration would allow LAN connections (both of the machines are on 192.168.0.x) but not external connections.

 

I am also using SSL if this is significant with a cert file generated as detailed here: https://www.nomachine.com/AR10M00866

 

Any advice would be much appreciated! Thanks.

 

NoMachine Free 6.8.1 on both server and client machines.

Server running Ubuntu 18.04 LTS on a Virtual Display. Client running Windows 10.

[Haven]

Hello OES1,
NoMachine processes are connecting to each other by the localhost.
Please add also an exception for that. It could look like that:
iptables -A INPUT -p tcp -s localhost -j ACCEPT

[OES1]

Hi Haven,

 

Thanks this worked perfectly! Resolved

Cheers,

[Author]

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