iptables: No chain/target/match by that name.

>PROBLEM

When running a "iptables conntrack" command, for instance like this:

    iptables -A INPUT -p tcp --dport 8081 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

 

returns the error message:
  
  iptables: No chain/target/match by that name.

>SOLUTION

The solution may contemplate alternatives due different causes.
This post shows two of them.

>using linux on a openvz container

OpenVZ servers share a kernel with the host, and as a result, you cannot load any kernel modules, and do some other tasks.

(FROM: Enabling Conntrack for iptables to work on openvz container?_

Ask your service provider to turn on the NetFilter for the server.

>linux, but not a container

Check this link.

>ENV

OpenVz container