Re: default firewall utility changes for Debian 11 bullseye

[Thomas Pircher <thp+debian@p5r.uk>]

Stephan Seitz wrote:
> What would be the replacement for a simple single line like
> iptables -I INPUT -j DROP -s <ip>  -p tcp –dport 587 ?

You can use the iptables-translate. It is not foolproof and does not
always git the best results, but it can give you a good starting point
for your optimisations:

# iptables-translate -A INPUT -s 1.2.3.4  -p tcp --dport 587 -j DROP
nft add rule ip filter INPUT ip saddr 1.2.3.4 tcp dport 587 counter drop

Thomas