ipset: add page (#6411)

pages/linux/ipset.md

@@ -0,0 +1,24 @@
+# ipset
+
+> A tool to create IP sets for firewall rules.
+> More information: <https://manned.org/ipset>.
+
+- Create an empty IP set which will contain IP addresses:
+
+`ipset create {{set_name}} hash:ip`
+
+- Destroy a specific IP set:
+
+`ipset destroy {{set_name}}`
+
+- Add an IP address to a specific set:
+
+`ipset add {{set_name}} {{192.168.1.25}}`
+
+- Delete a specific IP address from a set:
+
+`ipset del {{set_name}} {{192.168.1.25}}`
+
+- Save an IP set:
+
+`ipset save {{set_name}} > {{path/to/ip_set}}`