Preventing other applications from using a port
One of my applications uses randomly-selected ports from a port range to listen on. By default, 40000-59999.
The application runs on a firewalled server, and of course expects me to open the whole range on the firewall.
I'm not comfortable opening a large range of ports, most of which will never be used. The main concern is that another application may, also randomly, choose a port in that range and end up open to the world. I can configure the port range to be smaller, which would reduce the problem somewhat, but not truly solve it.
I have two ideas how to solve this conceptually, but don't know how/if it can actually be implemented. Operating system is RedHat Linux 7.4. The firewall is iptables/firewalld. SELinux is disabled (yes, I know, I don't like that either...)
My first idea: somehow "magically" prevent all other applications from binding to ports in this range. SELinux might be able to do that, but unfortunately I cannot use SELinux on that server (another application chokes on it).
My second idea: somehow get iptables to open ports by executable instead of by port number. This is a feature in the Windows firewall, but I don't think I have seen a way to do this with iptables.
What I'm looking for is ideas for implementing either of my ideas, or a third approach.
linux iptables
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One of my applications uses randomly-selected ports from a port range to listen on. By default, 40000-59999.
The application runs on a firewalled server, and of course expects me to open the whole range on the firewall.
I'm not comfortable opening a large range of ports, most of which will never be used. The main concern is that another application may, also randomly, choose a port in that range and end up open to the world. I can configure the port range to be smaller, which would reduce the problem somewhat, but not truly solve it.
I have two ideas how to solve this conceptually, but don't know how/if it can actually be implemented. Operating system is RedHat Linux 7.4. The firewall is iptables/firewalld. SELinux is disabled (yes, I know, I don't like that either...)
My first idea: somehow "magically" prevent all other applications from binding to ports in this range. SELinux might be able to do that, but unfortunately I cannot use SELinux on that server (another application chokes on it).
My second idea: somehow get iptables to open ports by executable instead of by port number. This is a feature in the Windows firewall, but I don't think I have seen a way to do this with iptables.
What I'm looking for is ideas for implementing either of my ideas, or a third approach.
linux iptables
add a comment |
One of my applications uses randomly-selected ports from a port range to listen on. By default, 40000-59999.
The application runs on a firewalled server, and of course expects me to open the whole range on the firewall.
I'm not comfortable opening a large range of ports, most of which will never be used. The main concern is that another application may, also randomly, choose a port in that range and end up open to the world. I can configure the port range to be smaller, which would reduce the problem somewhat, but not truly solve it.
I have two ideas how to solve this conceptually, but don't know how/if it can actually be implemented. Operating system is RedHat Linux 7.4. The firewall is iptables/firewalld. SELinux is disabled (yes, I know, I don't like that either...)
My first idea: somehow "magically" prevent all other applications from binding to ports in this range. SELinux might be able to do that, but unfortunately I cannot use SELinux on that server (another application chokes on it).
My second idea: somehow get iptables to open ports by executable instead of by port number. This is a feature in the Windows firewall, but I don't think I have seen a way to do this with iptables.
What I'm looking for is ideas for implementing either of my ideas, or a third approach.
linux iptables
One of my applications uses randomly-selected ports from a port range to listen on. By default, 40000-59999.
The application runs on a firewalled server, and of course expects me to open the whole range on the firewall.
I'm not comfortable opening a large range of ports, most of which will never be used. The main concern is that another application may, also randomly, choose a port in that range and end up open to the world. I can configure the port range to be smaller, which would reduce the problem somewhat, but not truly solve it.
I have two ideas how to solve this conceptually, but don't know how/if it can actually be implemented. Operating system is RedHat Linux 7.4. The firewall is iptables/firewalld. SELinux is disabled (yes, I know, I don't like that either...)
My first idea: somehow "magically" prevent all other applications from binding to ports in this range. SELinux might be able to do that, but unfortunately I cannot use SELinux on that server (another application chokes on it).
My second idea: somehow get iptables to open ports by executable instead of by port number. This is a feature in the Windows firewall, but I don't think I have seen a way to do this with iptables.
What I'm looking for is ideas for implementing either of my ideas, or a third approach.
linux iptables
linux iptables
asked 21 mins ago
Kevin Keane
325111
325111
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