# Copyright 1999-2023 Gentoo Authors # Distributed under the terms of the GNU General Public License v2 # This file contains descriptions of XTABLES_ADDONS USE-EXPANDED variables. # Keep it sorted. account - ACCOUNT target is a high performance accounting system for large local networks asn - match a packet by its source or destination Autonomous System Number chaos - CHAOS target causes confusion on the other end by doing odd things with incoming packets condition - matches if a specific condition variable is (un)set delude - DELUDE target will reply to a SYN packet with SYN-ACK, and to all other packets with an RST dhcpmac - DHCPMAC target/match in conjunction with ebtables can be used to completely change all MAC addresses from and to a VMware-based virtual machine dnetmap - DNETMAP target allows dynamic two-way 1:1 mapping of IPv4 subnets echo - ECHO target sends back all packets it received fuzzy - matches a rate limit based on a fuzzy logic controller (FLC) geoip - match a packet by its source or destination country gradm - match packets based on grsecurity RBAC status iface - match allows to check interface states ipmark - IPMARK target allows mark a received packet basing on its IP address ipp2p - matches certain packets in P2P flows ipv4options - match against a set of IPv4 header options length2 - matches the length of a packet against a specific value or range of values logmark - LOGMARK target will log packet and connection marks to syslog lscan - match detects simple low-level scan attemps based upon the packet's contents quota2 - match implements a named counter which can be increased or decreased on a per-match basis pknock - match implements so-called "port knocking", a stealthy system for network authentication proto - modifies the protocol number in IP packet header psd - match attempts to detect TCP and UDP port scans (derived from Solar Designer's scanlogd) sysrq - SYSRQ target allows to remotely trigger sysrq on the local machine over the network tarpit - TARPIT target captures and holds incoming TCP connections using no local per-connection resources