netstat is now considered too old to be used in new code.

Fair, but you'd think the latest most advanced model of GPT 4o1 (eg strawberry) would be able to successfully complete this task.

4o1 mini seems to have got it right. The trick is to give it minimal direction and let it do its thing.

netstat -an | while IFS= read -r line; do ips=$(echo "$line" | grep -oE '([0-9]{1,3}\.){3}[0-9]{1,3}|([a-fA-F0-9]{1,4}:){1,7}[a-fA-F0-9]{1,4}'); for ip in $ips; do clean_ip=$(echo "$ip" | cut -d'%' -f1); fqdn=$(dig +short -x "$clean_ip" | grep '\.'); if [ -n "$fqdn" ]; then line=$(echo "$line" | sed "s/$ip/$fqdn/g"); fi; done; echo "$line"; done