iptables vs nftables on Ubuntu
On current Ubuntu the iptables command already writes nftables rules. Prove it on your box, read the native ruleset, and see where ufw and Docker collide.
#nftables
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List the active firewall rules on Ubuntu
Three views of one ruleset on Ubuntu: nft list ruleset, iptables -L -n -v and ufw status. Find shadowed rules with counters and see why Docker skips ufw.
Install Fail2ban on Ubuntu 24.04: stop SSH bots
On Ubuntu 24.04 a plain apt install already bans SSH brute force. The fail2ban-client status sshd output proves it, plus the fix when Total failed stays at 0.
Self-host a WireGuard VPN on your VPS
Set up WireGuard on your own Linux VPS: key generation, wg0.conf, IP forwarding, NAT, AllowedIPs semantics, DNS, and the handshake failures that bite.