iptables, nft: add masquerade example (#6979)

pages/linux/iptables.md

@@ -19,6 +19,10 @@
 
 `sudo iptables -A {{chain}} -s {{ip}} -p {{protocol}} --dport {{port}} -j {{rule}}`
 
+- Add a NAT rule to translate all traffic from the `192.168.0.0/24` subnet to the host's public IP:
+
+`sudo iptables -t {{nat}} -A {{POSTROUTING}} -s {{192.168.0.0/24}} -j {{MASQUERADE}}`
+
 - Delete chain rule:
 
 `sudo iptables -D {{chain}} {{rule_line_number}}`

pages/linux/nft.md

@@ -20,6 +20,10 @@
 
 `sudo nft add rule {{inet}} {{filter}} {{input}} {{tcp}} {{dport \{ telnet, ssh, http, https \} accept}}`
 
+- Add a NAT rule to translate all traffic from the `192.168.0.0/24` subnet to the host's public IP:
+
+`sudo nft add rule {{nat}} {{postrouting}} ip saddr {{192.168.0.0/24}} {{masquerade}}`
+
 - Show rule handles:
 
 `sudo nft --handle --numeric list chain {{family}} {{table}} {{chain}}`