Sending and receiving UDP packets?

The receiver must set port of receiver to match port set in sender DatagramPacket. For debugging, try listening on port > 1024 (e.g. 5000 or 9000). Ports < 1024 are normally used by system services and need admin access to bind on such a port. If the receiver sends packet to the hard-coded port it’s … Read more

Open firewall port on CentOS 7 [closed]

Use this command to find your active zone(s): firewall-cmd –get-active-zones It will say either public, dmz, or something else. You should only apply to the zones required. In the case of public try: firewall-cmd –zone=public –add-port=2888/tcp –permanent Then remember to reload the firewall for changes to take effect. firewall-cmd –reload Otherwise, substitute public for your … Read more

What is the best practice of docker + ufw under Ubuntu

Problem This problem has been around for a long time. Disable iptables in Docker will take other problems. Rollback changes first If you have modified your server according to the current solution that we find on the internet, please rollback these changes first, including: Enable Docker’s iptables feature. Remove all changes like –iptables=false , including … Read more