Description of Linux Iptables Parameters

Description of matching parameters:

-- Source (-s) ----------- match the source IP address

-- Destination (-d) --------- match the destination IP address

-- Protocol (-p) ----------- matching protocol

-- In-interface (-I) ---------- entry

-- Out-interface (-o) ----------- exit

-- State ------------------------ match a group of connection statuses

-- String ------------------------- match the direct sequence of application-layer data

-- Comment ----------------------- how many 256 bytes of comment data are associated for a rule in the kernel memory

Target parameters:

ACCEPT ---------------------- allow data packets to pass

DROP ------------------------- discard data packets

LOG --------------------------- record data to syslog

REJECT ------------------------- discard data packets and send appropriate response packets

RETURN -------------------------- continue to process data packets in the call chain