Ensure port availability

Make sure required ports are available.

Before installing Redis Enterprise Software, make sure all required ports are available.

If ports that Redis assigns to the database are being used by the operating system or other processes, the installation fails.

Follow the relevant sections to configure required ports.

For recommended and optional port configuration, see Network port configurations.

Update sysctl.conf to avoid port collisions

To avoid port collision, update /etc/sysctl.conf to include:

net.ipv4.ip_local_port_range = 30000 65535

OS conflicts with port 53

If port 53 is in use, the installation fails. This issue can occur in default installations of certain operating systems in which systemd-resolved (DNS server) or dnsmasq is running.

To prevent this issue, change the system configuration to make this port available before installation.

To prevent systemd-resolved from using port 53:

1. Edit /etc/systemd/resolved.conf:

   sudo vi /etc/systemd/resolved.conf
   

2. Add DNSStubListener=no as the last line in the file and save the file.

3. Rename the current /etc/resolv.conf file:

   sudo mv /etc/resolv.conf /etc/resolv.conf.orig
   

4. Create a symbolic link for /etc/resolv.conf:

   sudo ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
   

   Note:

   You might encounter a temporary name resolution error (sudo: unable to resolve host {hostname}: Temporary failure in name resolution), which should be fixed when you restart systemd-resolved in the next step.

5. Restart the DNS service:

   sudo service systemd-resolved restart
   

To prevent dnsmasq from using port 53:

1. Stop the dnsmasq service if it's running:

   sudo systemctl stop dnsmasq
   

2. Prevent dnsmasq from starting automatically at system boot:

   sudo systemctl disable dnsmasq
   

3. Mask dnsmasq to prevent it from being started manually or by other services:

   sudo systemctl mask dnsmasq
   

4. Verify dnsmasq is no longer active and won't start at system boot:

   sudo systemctl status dnsmasq