How to view and edit the ephemeral port range on Linux?

linux unix networking network-programming unix-socket
Steephen picture Steephen · Feb 18, 2015 · Viewed 20.9k times · Source

In my Linux system ephemeral port range is showing different ranges as follows

$ cat /proc/sys/net/ipv4/ip_local_port_range 
32768  61000 


cat /etc/sysctl.conf | grep net.ipv4.ip_local_port_range
net.ipv4.ip_local_port_range = 9000 65500

Which will be the effective ephemeral port range in my system?

Answer

Steephen picture Steephen · Feb 18, 2015

Following command will list the ephemeral port range in Linux system

sysctl -A | grep ip_local_port_range

If we don't want to reboot, after editing /etc/sysctl.conf file if we execute following command it will be effective.

sysctl -p /etc/sysctl.conf .

The truth of the matter of effective range is output of

sysctl net.ipv4.ip_local_port_range

as mentioned by eckes in comment.

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