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TMA-ROCKY9-3.3.1.1

Ensure net.ipv4.ip_forward is configured

MittelStufe 1Automatisiertlinux

Beschreibung

The net.ipv4.ip_forward flag tells the system whether it can forward IPv4 packets or not. More information about the kernel parameter configuration files, their location, and load preference is available in the "Configure Network Kernel Parameters" section overview. Note: • If this system is a router this recommendation is not applicable. • If net.ipv4.conf.all.forwarding=0 and net.ipv4.conf.default.forwarding=0 are configured, this recommendation may be skipped.

So wird geprüft

Prüfmethode: Shell-Befehl

shell
chk() { p=$1; allowed=" $2 "; case $p in net.ipv6.*) [ -d /proc/sys/net/ipv6 ] || return 0;; esac; v=$(sysctl -n "$p" 2>/dev/null) || { echo "$p: not available"; return 1; }; case "$allowed" in *" $v "*) ;; *) echo "$p is $v (running)"; return 1;; esac; sd=$(readlink -e /lib/systemd/systemd-sysctl || readlink -e /usr/lib/systemd/systemd-sysctl); f=$("$sd" --cat-config 2>/dev/null | grep -Po "^\h*${p//./\.}\h*=\h*\K\H+" | tail -n1); [ -n "$f" ] || { echo "$p is not set in any sysctl configuration file"; return 1; }; case "$allowed" in *" $f "*) ;; *) echo "$p is $f in configuration"; return 1;; esac; }; if chk net.ipv4.ip_forward 0; then echo compliant; fi
Erwartete Ausgabe
compliant

So wird behoben

Behebungsmethode: Anleitung oder Infrastruktur-Patch

1. Review all files being used by systemd-sysctl and comment out or remove all net.ipv4.ip_forward lines that are not net.ipv4.ip_forward=0. Example script: #!/usr/bin/env bash { l_option="net.ipv4.ip_forward" l_value="0" l_grep="${l_option//./(\\.|\\/)}" a_files=() l_systemdsysctl="$(readlink -e /lib/systemd/systemd-sysctl \ || readlink -e /usr/lib/systemd/systemd-sysctl)" a_files+=("/etc/sysctl.conf") while IFS= read -r l_fname; do l_file="$(readlink -e "${l_fname//# /}")" [ -n "$l_file" ] && ! grep -Psiq -- '(^|\h+)'"$l_file"'\b' \ <<< "${a_files[*]}" && a_files+=("$l_file") done < <("$l_systemdsysctl" --cat-config | tac | \ grep -Psio -- '^\h*#\h*\/[^#\n\r\h]+\.conf\b') for l_file in "${…

Eigenschaften

Betriebssysteme
rocky-9
Tags
cis-convertedkernellinuxsysctl
Referenz
CIS Rocky Linux 9 Benchmark v3.0.0 - 3.3.1.1

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