2 # IP netfilter configuration
5 menu "IP: Netfilter Configuration"
6 depends on INET && NETFILTER
8 config NF_CONNTRACK_IPV4
9 tristate "IPv4 support for new connection tracking (EXPERIMENTAL)"
10 depends on EXPERIMENTAL && NF_CONNTRACK
12 Connection tracking keeps a record of what packets have passed
13 through your machine, in order to figure out how they are related
16 This is IPv4 support on Layer 3 independent connection tracking.
17 Layer 3 independent connection tracking is experimental scheme
18 which generalize ip_conntrack to support other layer 3 protocols.
20 To compile it as a module, choose M here. If unsure, say N.
22 # connection tracking, helpers and protocols
23 config IP_NF_CONNTRACK
24 tristate "Connection tracking (required for masq/NAT)"
26 Connection tracking keeps a record of what packets have passed
27 through your machine, in order to figure out how they are related
30 This is required to do Masquerading or other kinds of Network
31 Address Translation (except for Fast NAT). It can also be used to
32 enhance packet filtering (see `Connection state match support'
35 To compile it as a module, choose M here. If unsure, say N.
38 bool "Connection tracking flow accounting"
39 depends on IP_NF_CONNTRACK
41 If this option is enabled, the connection tracking code will
42 keep per-flow packet and byte counters.
44 Those counters can be used for flow-based accounting or the
49 config IP_NF_CONNTRACK_MARK
50 bool 'Connection mark tracking support'
51 depends on IP_NF_CONNTRACK
53 This option enables support for connection marks, used by the
54 `CONNMARK' target and `connmark' match. Similar to the mark value
55 of packets, but this mark value is kept in the conntrack session
56 instead of the individual packets.
58 config IP_NF_CONNTRACK_EVENTS
59 bool "Connection tracking events (EXPERIMENTAL)"
60 depends on EXPERIMENTAL && IP_NF_CONNTRACK
62 If this option is enabled, the connection tracking code will
63 provide a notifier chain that can be used by other kernel code
64 to get notified about changes in the connection tracking state.
68 config IP_NF_CONNTRACK_NETLINK
69 tristate 'Connection tracking netlink interface (EXPERIMENTAL)'
70 depends on EXPERIMENTAL && IP_NF_CONNTRACK && NETFILTER_NETLINK
71 depends on IP_NF_CONNTRACK!=y || NETFILTER_NETLINK!=m
73 This option enables support for a netlink-based userspace interface
76 config IP_NF_CT_PROTO_SCTP
77 tristate 'SCTP protocol connection tracking support (EXPERIMENTAL)'
78 depends on IP_NF_CONNTRACK && EXPERIMENTAL
80 With this option enabled, the connection tracking code will
81 be able to do state tracking on SCTP connections.
83 If you want to compile it as a module, say M here and read
84 <file:Documentation/modules.txt>. If unsure, say `N'.
87 tristate "FTP protocol support"
88 depends on IP_NF_CONNTRACK
90 Tracking FTP connections is problematic: special helpers are
91 required for tracking them, and doing masquerading and other forms
92 of Network Address Translation on them.
94 To compile it as a module, choose M here. If unsure, say Y.
97 tristate "IRC protocol support"
98 depends on IP_NF_CONNTRACK
100 There is a commonly-used extension to IRC called
101 Direct Client-to-Client Protocol (DCC). This enables users to send
102 files to each other, and also chat to each other without the need
103 of a server. DCC Sending is used anywhere you send files over IRC,
104 and DCC Chat is most commonly used by Eggdrop bots. If you are
105 using NAT, this extension will enable you to send files and initiate
106 chats. Note that you do NOT need this extension to get files or
107 have others initiate chats, or everything else in IRC.
109 To compile it as a module, choose M here. If unsure, say Y.
111 config IP_NF_NETBIOS_NS
112 tristate "NetBIOS name service protocol support (EXPERIMENTAL)"
113 depends on IP_NF_CONNTRACK && EXPERIMENTAL
115 NetBIOS name service requests are sent as broadcast messages from an
116 unprivileged port and responded to with unicast messages to the
117 same port. This make them hard to firewall properly because connection
118 tracking doesn't deal with broadcasts. This helper tracks locally
119 originating NetBIOS name service requests and the corresponding
120 responses. It relies on correct IP address configuration, specifically
121 netmask and broadcast address. When properly configured, the output
122 of "ip address show" should look similar to this:
124 $ ip -4 address show eth0
125 4: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000
126 inet 172.16.2.252/24 brd 172.16.2.255 scope global eth0
128 To compile it as a module, choose M here. If unsure, say N.
131 tristate "TFTP protocol support"
132 depends on IP_NF_CONNTRACK
134 TFTP connection tracking helper, this is required depending
135 on how restrictive your ruleset is.
136 If you are using a tftp client behind -j SNAT or -j MASQUERADING
139 To compile it as a module, choose M here. If unsure, say Y.
142 tristate "Amanda backup protocol support"
143 depends on IP_NF_CONNTRACK
145 If you are running the Amanda backup package <http://www.amanda.org/>
146 on this machine or machines that will be MASQUERADED through this
147 machine, then you may want to enable this feature. This allows the
148 connection tracking and natting code to allow the sub-channels that
149 Amanda requires for communication of the backup data, messages and
152 To compile it as a module, choose M here. If unsure, say Y.
155 tristate 'PPTP protocol support'
156 depends on IP_NF_CONNTRACK
158 This module adds support for PPTP (Point to Point Tunnelling
159 Protocol, RFC2637) connection tracking and NAT.
161 If you are running PPTP sessions over a stateful firewall or NAT
162 box, you may want to enable this feature.
164 Please note that not all PPTP modes of operation are supported yet.
165 For more info, read top of the file
166 net/ipv4/netfilter/ip_conntrack_pptp.c
168 If you want to compile it as a module, say M here and read
169 Documentation/modules.txt. If unsure, say `N'.
172 tristate "IP Userspace queueing via NETLINK (OBSOLETE)"
174 Netfilter has the ability to queue packets to user space: the
175 netlink device can be used to access them using this driver.
177 This option enables the old IPv4-only "ip_queue" implementation
178 which has been obsoleted by the new "nfnetlink_queue" code (see
179 CONFIG_NETFILTER_NETLINK_QUEUE).
181 To compile it as a module, choose M here. If unsure, say N.
183 config IP_NF_IPTABLES
184 tristate "IP tables support (required for filtering/masq/NAT)"
185 depends on NETFILTER_XTABLES
187 iptables is a general, extensible packet identification framework.
188 The packet filtering and full NAT (masquerading, port forwarding,
189 etc) subsystems now use this: say `Y' or `M' here if you want to use
192 To compile it as a module, choose M here. If unsure, say N.
195 config IP_NF_MATCH_IPRANGE
196 tristate "IP range match support"
197 depends on IP_NF_IPTABLES
199 This option makes possible to match IP addresses against IP address
202 To compile it as a module, choose M here. If unsure, say N.
204 config IP_NF_MATCH_MULTIPORT
205 tristate "Multiple port match support"
206 depends on IP_NF_IPTABLES
208 Multiport matching allows you to match TCP or UDP packets based on
209 a series of source or destination ports: normally a rule can only
210 match a single range of ports.
212 To compile it as a module, choose M here. If unsure, say N.
214 config IP_NF_MATCH_TOS
215 tristate "TOS match support"
216 depends on IP_NF_IPTABLES
218 TOS matching allows you to match packets based on the Type Of
219 Service fields of the IP packet.
221 To compile it as a module, choose M here. If unsure, say N.
223 config IP_NF_MATCH_RECENT
224 tristate "recent match support"
225 depends on IP_NF_IPTABLES
227 This match is used for creating one or many lists of recently
228 used addresses and then matching against that/those list(s).
230 Short options are available by using 'iptables -m recent -h'
231 Official Website: <http://snowman.net/projects/ipt_recent/>
233 To compile it as a module, choose M here. If unsure, say N.
235 config IP_NF_MATCH_ECN
236 tristate "ECN match support"
237 depends on IP_NF_IPTABLES
239 This option adds a `ECN' match, which allows you to match against
240 the IPv4 and TCP header ECN fields.
242 To compile it as a module, choose M here. If unsure, say N.
244 config IP_NF_MATCH_DSCP
245 tristate "DSCP match support"
246 depends on IP_NF_IPTABLES
248 This option adds a `DSCP' match, which allows you to match against
249 the IPv4 header DSCP field (DSCP codepoint).
251 The DSCP codepoint can have any value between 0x0 and 0x4f.
253 To compile it as a module, choose M here. If unsure, say N.
255 config IP_NF_MATCH_AH_ESP
256 tristate "AH/ESP match support"
257 depends on IP_NF_IPTABLES
259 These two match extensions (`ah' and `esp') allow you to match a
260 range of SPIs inside AH or ESP headers of IPSec packets.
262 To compile it as a module, choose M here. If unsure, say N.
264 config IP_NF_MATCH_TTL
265 tristate "TTL match support"
266 depends on IP_NF_IPTABLES
268 This adds CONFIG_IP_NF_MATCH_TTL option, which enabled the user
269 to match packets by their TTL value.
271 To compile it as a module, choose M here. If unsure, say N.
273 config IP_NF_MATCH_OWNER
274 tristate "Owner match support"
275 depends on IP_NF_IPTABLES
277 Packet owner matching allows you to match locally-generated packets
278 based on who created them: the user, group, process or session.
280 To compile it as a module, choose M here. If unsure, say N.
282 config IP_NF_MATCH_ADDRTYPE
283 tristate 'address type match support'
284 depends on IP_NF_IPTABLES
286 This option allows you to match what routing thinks of an address,
287 eg. UNICAST, LOCAL, BROADCAST, ...
289 If you want to compile it as a module, say M here and read
290 <file:Documentation/modules.txt>. If unsure, say `N'.
292 config IP_NF_MATCH_HASHLIMIT
293 tristate 'hashlimit match support'
294 depends on IP_NF_IPTABLES
296 This option adds a new iptables `hashlimit' match.
298 As opposed to `limit', this match dynamically crates a hash table
299 of limit buckets, based on your selection of source/destination
300 ip addresses and/or ports.
302 It enables you to express policies like `10kpps for any given
303 destination IP' or `500pps from any given source IP' with a single
306 config IP_NF_MATCH_POLICY
307 tristate "IPsec policy match support"
308 depends on IP_NF_IPTABLES && XFRM
310 Policy matching allows you to match packets based on the
311 IPsec policy that was used during decapsulation/will
312 be used during encapsulation.
314 To compile it as a module, choose M here. If unsure, say N.
316 # `filter', generic and specific targets
318 tristate "Packet filtering"
319 depends on IP_NF_IPTABLES
321 Packet filtering defines a table `filter', which has a series of
322 rules for simple packet filtering at local input, forwarding and
323 local output. See the man page for iptables(8).
325 To compile it as a module, choose M here. If unsure, say N.
327 config IP_NF_TARGET_REJECT
328 tristate "REJECT target support"
329 depends on IP_NF_FILTER
331 The REJECT target allows a filtering rule to specify that an ICMP
332 error should be issued in response to an incoming packet, rather
333 than silently being dropped.
335 To compile it as a module, choose M here. If unsure, say N.
337 config IP_NF_TARGET_LOG
338 tristate "LOG target support"
339 depends on IP_NF_IPTABLES
341 This option adds a `LOG' target, which allows you to create rules in
342 any iptables table which records the packet header to the syslog.
344 To compile it as a module, choose M here. If unsure, say N.
346 config IP_NF_TARGET_ULOG
347 tristate "ULOG target support (OBSOLETE)"
348 depends on IP_NF_IPTABLES
351 This option enables the old IPv4-only "ipt_ULOG" implementation
352 which has been obsoleted by the new "nfnetlink_log" code (see
353 CONFIG_NETFILTER_NETLINK_LOG).
355 This option adds a `ULOG' target, which allows you to create rules in
356 any iptables table. The packet is passed to a userspace logging
357 daemon using netlink multicast sockets; unlike the LOG target
358 which can only be viewed through syslog.
360 The apropriate userspace logging daemon (ulogd) may be obtained from
361 <http://www.gnumonks.org/projects/ulogd/>
363 To compile it as a module, choose M here. If unsure, say N.
365 config IP_NF_TARGET_TCPMSS
366 tristate "TCPMSS target support"
367 depends on IP_NF_IPTABLES
369 This option adds a `TCPMSS' target, which allows you to alter the
370 MSS value of TCP SYN packets, to control the maximum size for that
371 connection (usually limiting it to your outgoing interface's MTU
374 This is used to overcome criminally braindead ISPs or servers which
375 block ICMP Fragmentation Needed packets. The symptoms of this
376 problem are that everything works fine from your Linux
377 firewall/router, but machines behind it can never exchange large
379 1) Web browsers connect, then hang with no data received.
380 2) Small mail works fine, but large emails hang.
381 3) ssh works fine, but scp hangs after initial handshaking.
383 Workaround: activate this option and add a rule to your firewall
386 iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN \
387 -j TCPMSS --clamp-mss-to-pmtu
389 To compile it as a module, choose M here. If unsure, say N.
391 # NAT + specific targets
394 depends on IP_NF_IPTABLES && IP_NF_CONNTRACK
396 The Full NAT option allows masquerading, port forwarding and other
397 forms of full Network Address Port Translation. It is controlled by
398 the `nat' table in iptables: see the man page for iptables(8).
400 To compile it as a module, choose M here. If unsure, say N.
402 config IP_NF_NAT_NEEDED
404 depends on IP_NF_NAT != n
407 config IP_NF_TARGET_MASQUERADE
408 tristate "MASQUERADE target support"
411 Masquerading is a special case of NAT: all outgoing connections are
412 changed to seem to come from a particular interface's address, and
413 if the interface goes down, those connections are lost. This is
414 only useful for dialup accounts with dynamic IP address (ie. your IP
415 address will be different on next dialup).
417 To compile it as a module, choose M here. If unsure, say N.
419 config IP_NF_TARGET_REDIRECT
420 tristate "REDIRECT target support"
423 REDIRECT is a special case of NAT: all incoming connections are
424 mapped onto the incoming interface's address, causing the packets to
425 come to the local machine instead of passing through. This is
426 useful for transparent proxies.
428 To compile it as a module, choose M here. If unsure, say N.
430 config IP_NF_TARGET_NETMAP
431 tristate "NETMAP target support"
434 NETMAP is an implementation of static 1:1 NAT mapping of network
435 addresses. It maps the network address part, while keeping the host
436 address part intact. It is similar to Fast NAT, except that
437 Netfilter's connection tracking doesn't work well with Fast NAT.
439 To compile it as a module, choose M here. If unsure, say N.
441 config IP_NF_TARGET_SAME
442 tristate "SAME target support"
445 This option adds a `SAME' target, which works like the standard SNAT
446 target, but attempts to give clients the same IP for all connections.
448 To compile it as a module, choose M here. If unsure, say N.
450 config IP_NF_TARGET_IDLETIMER
451 tristate "IDLETIMER target support"
452 depends on IP_NF_IPTABLES
454 This option adds a `IDLETIMER' target. Each matching packet resets
455 the timer associated with input and/or output interfaces. Timer
456 expiry causes kobject uevent. Idle timer can be read via sysfs.
458 To compile it as a module, choose M here. If unsure, say N.
460 config IP_NF_NAT_SNMP_BASIC
461 tristate "Basic SNMP-ALG support (EXPERIMENTAL)"
462 depends on EXPERIMENTAL && IP_NF_NAT
465 This module implements an Application Layer Gateway (ALG) for
466 SNMP payloads. In conjunction with NAT, it allows a network
467 management system to access multiple private networks with
468 conflicting addresses. It works by modifying IP addresses
469 inside SNMP payloads to match IP-layer NAT mapping.
471 This is the "basic" form of SNMP-ALG, as described in RFC 2962
473 To compile it as a module, choose M here. If unsure, say N.
477 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
478 default IP_NF_NAT if IP_NF_IRC=y
479 default m if IP_NF_IRC=m
481 # If they want FTP, set to $CONFIG_IP_NF_NAT (m or y),
482 # or $CONFIG_IP_NF_FTP (m or y), whichever is weaker. Argh.
485 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
486 default IP_NF_NAT if IP_NF_FTP=y
487 default m if IP_NF_FTP=m
489 config IP_NF_NAT_TFTP
491 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
492 default IP_NF_NAT if IP_NF_TFTP=y
493 default m if IP_NF_TFTP=m
495 config IP_NF_NAT_AMANDA
497 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
498 default IP_NF_NAT if IP_NF_AMANDA=y
499 default m if IP_NF_AMANDA=m
501 config IP_NF_NAT_PPTP
503 depends on IP_NF_NAT!=n && IP_NF_PPTP!=n
504 default IP_NF_NAT if IP_NF_PPTP=y
505 default m if IP_NF_PPTP=m
507 # mangle + specific targets
509 tristate "Packet mangling"
510 depends on IP_NF_IPTABLES
512 This option adds a `mangle' table to iptables: see the man page for
513 iptables(8). This table is used for various packet alterations
514 which can effect how the packet is routed.
516 To compile it as a module, choose M here. If unsure, say N.
518 config IP_NF_TARGET_TOS
519 tristate "TOS target support"
520 depends on IP_NF_MANGLE
522 This option adds a `TOS' target, which allows you to create rules in
523 the `mangle' table which alter the Type Of Service field of an IP
524 packet prior to routing.
526 To compile it as a module, choose M here. If unsure, say N.
528 config IP_NF_TARGET_ECN
529 tristate "ECN target support"
530 depends on IP_NF_MANGLE
532 This option adds a `ECN' target, which can be used in the iptables mangle
535 You can use this target to remove the ECN bits from the IPv4 header of
536 an IP packet. This is particularly useful, if you need to work around
537 existing ECN blackholes on the internet, but don't want to disable
538 ECN support in general.
540 To compile it as a module, choose M here. If unsure, say N.
542 config IP_NF_TARGET_DSCP
543 tristate "DSCP target support"
544 depends on IP_NF_MANGLE
546 This option adds a `DSCP' match, which allows you to match against
547 the IPv4 header DSCP field (DSCP codepoint).
549 The DSCP codepoint can have any value between 0x0 and 0x4f.
551 To compile it as a module, choose M here. If unsure, say N.
553 config IP_NF_TARGET_TTL
554 tristate 'TTL target support'
555 depends on IP_NF_MANGLE
557 This option adds a `TTL' target, which enables the user to modify
558 the TTL value of the IP header.
560 While it is safe to decrement/lower the TTL, this target also enables
561 functionality to increment and set the TTL value of the IP header to
562 arbitrary values. This is EXTREMELY DANGEROUS since you can easily
563 create immortal packets that loop forever on the network.
565 To compile it as a module, choose M here. If unsure, say N.
567 config IP_NF_TARGET_CLUSTERIP
568 tristate "CLUSTERIP target support (EXPERIMENTAL)"
569 depends on IP_NF_MANGLE && EXPERIMENTAL
570 depends on (IP_NF_CONNTRACK && IP_NF_CONNTRACK_MARK) || (NF_CONNTRACK_MARK && NF_CONNTRACK_IPV4)
572 The CLUSTERIP target allows you to build load-balancing clusters of
573 network servers without having a dedicated load-balancing
574 router/server/switch.
576 To compile it as a module, choose M here. If unsure, say N.
578 # raw + specific targets
580 tristate 'raw table support (required for NOTRACK/TRACE)'
581 depends on IP_NF_IPTABLES
583 This option adds a `raw' table to iptables. This table is the very
584 first in the netfilter framework and hooks in at the PREROUTING
587 If you want to compile it as a module, say M here and read
588 <file:Documentation/modules.txt>. If unsure, say `N'.
591 config IP_NF_ARPTABLES
592 tristate "ARP tables support"
593 depends on NETFILTER_XTABLES
595 arptables is a general, extensible packet identification framework.
596 The ARP packet filtering and mangling (manipulation)subsystems
597 use this: say Y or M here if you want to use either of those.
599 To compile it as a module, choose M here. If unsure, say N.
601 config IP_NF_ARPFILTER
602 tristate "ARP packet filtering"
603 depends on IP_NF_ARPTABLES
605 ARP packet filtering defines a table `filter', which has a series of
606 rules for simple ARP packet filtering at local input and
607 local output. On a bridge, you can also specify filtering rules
608 for forwarded ARP packets. See the man page for arptables(8).
610 To compile it as a module, choose M here. If unsure, say N.
612 config IP_NF_ARP_MANGLE
613 tristate "ARP payload mangling"
614 depends on IP_NF_ARPTABLES
616 Allows altering the ARP packet payload: source and destination
617 hardware and network addresses.