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
72 depends on IP_NF_NAT=n || IP_NF_NAT
74 This option enables support for a netlink-based userspace interface
77 config IP_NF_CT_PROTO_SCTP
78 tristate 'SCTP protocol connection tracking support (EXPERIMENTAL)'
79 depends on IP_NF_CONNTRACK && EXPERIMENTAL
81 With this option enabled, the connection tracking code will
82 be able to do state tracking on SCTP connections.
84 If you want to compile it as a module, say M here and read
85 <file:Documentation/modules.txt>. If unsure, say `N'.
88 tristate "FTP protocol support"
89 depends on IP_NF_CONNTRACK
91 Tracking FTP connections is problematic: special helpers are
92 required for tracking them, and doing masquerading and other forms
93 of Network Address Translation on them.
95 To compile it as a module, choose M here. If unsure, say Y.
98 tristate "IRC protocol support"
99 depends on IP_NF_CONNTRACK
101 There is a commonly-used extension to IRC called
102 Direct Client-to-Client Protocol (DCC). This enables users to send
103 files to each other, and also chat to each other without the need
104 of a server. DCC Sending is used anywhere you send files over IRC,
105 and DCC Chat is most commonly used by Eggdrop bots. If you are
106 using NAT, this extension will enable you to send files and initiate
107 chats. Note that you do NOT need this extension to get files or
108 have others initiate chats, or everything else in IRC.
110 To compile it as a module, choose M here. If unsure, say Y.
112 config IP_NF_NETBIOS_NS
113 tristate "NetBIOS name service protocol support (EXPERIMENTAL)"
114 depends on IP_NF_CONNTRACK && EXPERIMENTAL
116 NetBIOS name service requests are sent as broadcast messages from an
117 unprivileged port and responded to with unicast messages to the
118 same port. This make them hard to firewall properly because connection
119 tracking doesn't deal with broadcasts. This helper tracks locally
120 originating NetBIOS name service requests and the corresponding
121 responses. It relies on correct IP address configuration, specifically
122 netmask and broadcast address. When properly configured, the output
123 of "ip address show" should look similar to this:
125 $ ip -4 address show eth0
126 4: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000
127 inet 172.16.2.252/24 brd 172.16.2.255 scope global eth0
129 To compile it as a module, choose M here. If unsure, say N.
132 tristate "TFTP protocol support"
133 depends on IP_NF_CONNTRACK
135 TFTP connection tracking helper, this is required depending
136 on how restrictive your ruleset is.
137 If you are using a tftp client behind -j SNAT or -j MASQUERADING
140 To compile it as a module, choose M here. If unsure, say Y.
143 tristate "Amanda backup protocol support"
144 depends on IP_NF_CONNTRACK
146 select TEXTSEARCH_KMP
148 If you are running the Amanda backup package <http://www.amanda.org/>
149 on this machine or machines that will be MASQUERADED through this
150 machine, then you may want to enable this feature. This allows the
151 connection tracking and natting code to allow the sub-channels that
152 Amanda requires for communication of the backup data, messages and
155 To compile it as a module, choose M here. If unsure, say Y.
158 tristate 'PPTP protocol support'
159 depends on IP_NF_CONNTRACK
161 This module adds support for PPTP (Point to Point Tunnelling
162 Protocol, RFC2637) connection tracking and NAT.
164 If you are running PPTP sessions over a stateful firewall or NAT
165 box, you may want to enable this feature.
167 Please note that not all PPTP modes of operation are supported yet.
168 For more info, read top of the file
169 net/ipv4/netfilter/ip_conntrack_pptp.c
171 If you want to compile it as a module, say M here and read
172 Documentation/modules.txt. If unsure, say `N'.
175 tristate 'H.323 protocol support (EXPERIMENTAL)'
176 depends on IP_NF_CONNTRACK && EXPERIMENTAL
178 H.323 is a VoIP signalling protocol from ITU-T. As one of the most
179 important VoIP protocols, it is widely used by voice hardware and
180 software including voice gateways, IP phones, Netmeeting, OpenPhone,
183 With this module you can support H.323 on a connection tracking/NAT
186 This module supports RAS, Fast Start, H.245 Tunnelling, Call
187 Forwarding, RTP/RTCP and T.120 based audio, video, fax, chat,
188 whiteboard, file transfer, etc. For more information, please
189 visit http://nath323.sourceforge.net/.
191 If you want to compile it as a module, say 'M' here and read
192 Documentation/modules.txt. If unsure, say 'N'.
195 tristate "IP Userspace queueing via NETLINK (OBSOLETE)"
197 Netfilter has the ability to queue packets to user space: the
198 netlink device can be used to access them using this driver.
200 This option enables the old IPv4-only "ip_queue" implementation
201 which has been obsoleted by the new "nfnetlink_queue" code (see
202 CONFIG_NETFILTER_NETLINK_QUEUE).
204 To compile it as a module, choose M here. If unsure, say N.
206 config IP_NF_IPTABLES
207 tristate "IP tables support (required for filtering/masq/NAT)"
208 depends on NETFILTER_XTABLES
210 iptables is a general, extensible packet identification framework.
211 The packet filtering and full NAT (masquerading, port forwarding,
212 etc) subsystems now use this: say `Y' or `M' here if you want to use
215 To compile it as a module, choose M here. If unsure, say N.
218 config IP_NF_MATCH_IPRANGE
219 tristate "IP range match support"
220 depends on IP_NF_IPTABLES
222 This option makes possible to match IP addresses against IP address
225 To compile it as a module, choose M here. If unsure, say N.
227 config IP_NF_MATCH_TOS
228 tristate "TOS match support"
229 depends on IP_NF_IPTABLES
231 TOS matching allows you to match packets based on the Type Of
232 Service fields of the IP packet.
234 To compile it as a module, choose M here. If unsure, say N.
236 config IP_NF_MATCH_RECENT
237 tristate "recent match support"
238 depends on IP_NF_IPTABLES
240 This match is used for creating one or many lists of recently
241 used addresses and then matching against that/those list(s).
243 Short options are available by using 'iptables -m recent -h'
244 Official Website: <http://snowman.net/projects/ipt_recent/>
246 To compile it as a module, choose M here. If unsure, say N.
248 config IP_NF_MATCH_ECN
249 tristate "ECN match support"
250 depends on IP_NF_IPTABLES
252 This option adds a `ECN' match, which allows you to match against
253 the IPv4 and TCP header ECN fields.
255 To compile it as a module, choose M here. If unsure, say N.
257 config IP_NF_MATCH_DSCP
258 tristate "DSCP match support"
259 depends on IP_NF_IPTABLES
261 This option adds a `DSCP' match, which allows you to match against
262 the IPv4 header DSCP field (DSCP codepoint).
264 The DSCP codepoint can have any value between 0x0 and 0x4f.
266 To compile it as a module, choose M here. If unsure, say N.
268 config IP_NF_MATCH_AH
269 tristate "AH match support"
270 depends on IP_NF_IPTABLES
272 This match extension allows you to match a range of SPIs
273 inside AH header of IPSec packets.
275 To compile it as a module, choose M here. If unsure, say N.
277 config IP_NF_MATCH_TTL
278 tristate "TTL match support"
279 depends on IP_NF_IPTABLES
281 This adds CONFIG_IP_NF_MATCH_TTL option, which enabled the user
282 to match packets by their TTL value.
284 To compile it as a module, choose M here. If unsure, say N.
286 config IP_NF_MATCH_OWNER
287 tristate "Owner match support"
288 depends on IP_NF_IPTABLES
290 Packet owner matching allows you to match locally-generated packets
291 based on who created them: the user, group, process or session.
293 To compile it as a module, choose M here. If unsure, say N.
295 config IP_NF_MATCH_ADDRTYPE
296 tristate 'address type match support'
297 depends on IP_NF_IPTABLES
299 This option allows you to match what routing thinks of an address,
300 eg. UNICAST, LOCAL, BROADCAST, ...
302 If you want to compile it as a module, say M here and read
303 <file:Documentation/modules.txt>. If unsure, say `N'.
305 config IP_NF_MATCH_HASHLIMIT
306 tristate 'hashlimit match support'
307 depends on IP_NF_IPTABLES
309 This option adds a new iptables `hashlimit' match.
311 As opposed to `limit', this match dynamically crates a hash table
312 of limit buckets, based on your selection of source/destination
313 ip addresses and/or ports.
315 It enables you to express policies like `10kpps for any given
316 destination IP' or `500pps from any given source IP' with a single
319 # `filter', generic and specific targets
321 tristate "Packet filtering"
322 depends on IP_NF_IPTABLES
324 Packet filtering defines a table `filter', which has a series of
325 rules for simple packet filtering at local input, forwarding and
326 local output. See the man page for iptables(8).
328 To compile it as a module, choose M here. If unsure, say N.
330 config IP_NF_TARGET_REJECT
331 tristate "REJECT target support"
332 depends on IP_NF_FILTER
334 The REJECT target allows a filtering rule to specify that an ICMP
335 error should be issued in response to an incoming packet, rather
336 than silently being dropped.
338 To compile it as a module, choose M here. If unsure, say N.
340 config IP_NF_TARGET_LOG
341 tristate "LOG target support"
342 depends on IP_NF_IPTABLES
344 This option adds a `LOG' target, which allows you to create rules in
345 any iptables table which records the packet header to the syslog.
347 To compile it as a module, choose M here. If unsure, say N.
349 config IP_NF_TARGET_ULOG
350 tristate "ULOG target support"
351 depends on IP_NF_IPTABLES
354 This option enables the old IPv4-only "ipt_ULOG" implementation
355 which has been obsoleted by the new "nfnetlink_log" code (see
356 CONFIG_NETFILTER_NETLINK_LOG).
358 This option adds a `ULOG' target, which allows you to create rules in
359 any iptables table. The packet is passed to a userspace logging
360 daemon using netlink multicast sockets; unlike the LOG target
361 which can only be viewed through syslog.
363 The apropriate userspace logging daemon (ulogd) may be obtained from
364 <http://www.gnumonks.org/projects/ulogd/>
366 To compile it as a module, choose M here. If unsure, say N.
368 config IP_NF_TARGET_TCPMSS
369 tristate "TCPMSS target support"
370 depends on IP_NF_IPTABLES
372 This option adds a `TCPMSS' target, which allows you to alter the
373 MSS value of TCP SYN packets, to control the maximum size for that
374 connection (usually limiting it to your outgoing interface's MTU
377 This is used to overcome criminally braindead ISPs or servers which
378 block ICMP Fragmentation Needed packets. The symptoms of this
379 problem are that everything works fine from your Linux
380 firewall/router, but machines behind it can never exchange large
382 1) Web browsers connect, then hang with no data received.
383 2) Small mail works fine, but large emails hang.
384 3) ssh works fine, but scp hangs after initial handshaking.
386 Workaround: activate this option and add a rule to your firewall
389 iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN \
390 -j TCPMSS --clamp-mss-to-pmtu
392 To compile it as a module, choose M here. If unsure, say N.
394 # NAT + specific targets
397 depends on IP_NF_IPTABLES && IP_NF_CONNTRACK
399 The Full NAT option allows masquerading, port forwarding and other
400 forms of full Network Address Port Translation. It is controlled by
401 the `nat' table in iptables: see the man page for iptables(8).
403 To compile it as a module, choose M here. If unsure, say N.
405 config IP_NF_NAT_NEEDED
407 depends on IP_NF_NAT != n
410 config IP_NF_TARGET_MASQUERADE
411 tristate "MASQUERADE target support"
414 Masquerading is a special case of NAT: all outgoing connections are
415 changed to seem to come from a particular interface's address, and
416 if the interface goes down, those connections are lost. This is
417 only useful for dialup accounts with dynamic IP address (ie. your IP
418 address will be different on next dialup).
420 To compile it as a module, choose M here. If unsure, say N.
422 config IP_NF_TARGET_REDIRECT
423 tristate "REDIRECT target support"
426 REDIRECT is a special case of NAT: all incoming connections are
427 mapped onto the incoming interface's address, causing the packets to
428 come to the local machine instead of passing through. This is
429 useful for transparent proxies.
431 To compile it as a module, choose M here. If unsure, say N.
433 config IP_NF_TARGET_NETMAP
434 tristate "NETMAP target support"
437 NETMAP is an implementation of static 1:1 NAT mapping of network
438 addresses. It maps the network address part, while keeping the host
439 address part intact. It is similar to Fast NAT, except that
440 Netfilter's connection tracking doesn't work well with Fast NAT.
442 To compile it as a module, choose M here. If unsure, say N.
444 config IP_NF_TARGET_SAME
445 tristate "SAME target support"
448 This option adds a `SAME' target, which works like the standard SNAT
449 target, but attempts to give clients the same IP for all connections.
451 To compile it as a module, choose M here. If unsure, say N.
453 config IP_NF_NAT_SNMP_BASIC
454 tristate "Basic SNMP-ALG support (EXPERIMENTAL)"
455 depends on EXPERIMENTAL && IP_NF_NAT
458 This module implements an Application Layer Gateway (ALG) for
459 SNMP payloads. In conjunction with NAT, it allows a network
460 management system to access multiple private networks with
461 conflicting addresses. It works by modifying IP addresses
462 inside SNMP payloads to match IP-layer NAT mapping.
464 This is the "basic" form of SNMP-ALG, as described in RFC 2962
466 To compile it as a module, choose M here. If unsure, say N.
470 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
471 default IP_NF_NAT if IP_NF_IRC=y
472 default m if IP_NF_IRC=m
474 # If they want FTP, set to $CONFIG_IP_NF_NAT (m or y),
475 # or $CONFIG_IP_NF_FTP (m or y), whichever is weaker. Argh.
478 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
479 default IP_NF_NAT if IP_NF_FTP=y
480 default m if IP_NF_FTP=m
482 config IP_NF_NAT_TFTP
484 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
485 default IP_NF_NAT if IP_NF_TFTP=y
486 default m if IP_NF_TFTP=m
488 config IP_NF_NAT_AMANDA
490 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
491 default IP_NF_NAT if IP_NF_AMANDA=y
492 default m if IP_NF_AMANDA=m
494 config IP_NF_NAT_PPTP
496 depends on IP_NF_NAT!=n && IP_NF_PPTP!=n
497 default IP_NF_NAT if IP_NF_PPTP=y
498 default m if IP_NF_PPTP=m
500 config IP_NF_NAT_H323
502 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
503 default IP_NF_NAT if IP_NF_H323=y
504 default m if IP_NF_H323=m
506 # mangle + specific targets
508 tristate "Packet mangling"
509 depends on IP_NF_IPTABLES
511 This option adds a `mangle' table to iptables: see the man page for
512 iptables(8). This table is used for various packet alterations
513 which can effect how the packet is routed.
515 To compile it as a module, choose M here. If unsure, say N.
517 config IP_NF_TARGET_TOS
518 tristate "TOS target support"
519 depends on IP_NF_MANGLE
521 This option adds a `TOS' target, which allows you to create rules in
522 the `mangle' table which alter the Type Of Service field of an IP
523 packet prior to routing.
525 To compile it as a module, choose M here. If unsure, say N.
527 config IP_NF_TARGET_ECN
528 tristate "ECN target support"
529 depends on IP_NF_MANGLE
531 This option adds a `ECN' target, which can be used in the iptables mangle
534 You can use this target to remove the ECN bits from the IPv4 header of
535 an IP packet. This is particularly useful, if you need to work around
536 existing ECN blackholes on the internet, but don't want to disable
537 ECN support in general.
539 To compile it as a module, choose M here. If unsure, say N.
541 config IP_NF_TARGET_DSCP
542 tristate "DSCP target support"
543 depends on IP_NF_MANGLE
545 This option adds a `DSCP' match, which allows you to match against
546 the IPv4 header DSCP field (DSCP codepoint).
548 The DSCP codepoint can have any value between 0x0 and 0x4f.
550 To compile it as a module, choose M here. If unsure, say N.
552 config IP_NF_TARGET_TTL
553 tristate 'TTL target support'
554 depends on IP_NF_MANGLE
556 This option adds a `TTL' target, which enables the user to modify
557 the TTL value of the IP header.
559 While it is safe to decrement/lower the TTL, this target also enables
560 functionality to increment and set the TTL value of the IP header to
561 arbitrary values. This is EXTREMELY DANGEROUS since you can easily
562 create immortal packets that loop forever on the network.
564 To compile it as a module, choose M here. If unsure, say N.
566 config IP_NF_TARGET_CLUSTERIP
567 tristate "CLUSTERIP target support (EXPERIMENTAL)"
568 depends on IP_NF_MANGLE && EXPERIMENTAL
569 depends on (IP_NF_CONNTRACK && IP_NF_CONNTRACK_MARK) || (NF_CONNTRACK_MARK && NF_CONNTRACK_IPV4)
571 The CLUSTERIP target allows you to build load-balancing clusters of
572 network servers without having a dedicated load-balancing
573 router/server/switch.
575 To compile it as a module, choose M here. If unsure, say N.
577 # raw + specific targets
579 tristate 'raw table support (required for NOTRACK/TRACE)'
580 depends on IP_NF_IPTABLES
582 This option adds a `raw' table to iptables. This table is the very
583 first in the netfilter framework and hooks in at the PREROUTING
586 If you want to compile it as a module, say M here and read
587 <file:Documentation/modules.txt>. If unsure, say `N'.
590 config IP_NF_ARPTABLES
591 tristate "ARP tables support"
592 depends on NETFILTER_XTABLES
594 arptables is a general, extensible packet identification framework.
595 The ARP packet filtering and mangling (manipulation)subsystems
596 use this: say Y or M here if you want to use either of those.
598 To compile it as a module, choose M here. If unsure, say N.
600 config IP_NF_ARPFILTER
601 tristate "ARP packet filtering"
602 depends on IP_NF_ARPTABLES
604 ARP packet filtering defines a table `filter', which has a series of
605 rules for simple ARP packet filtering at local input and
606 local output. On a bridge, you can also specify filtering rules
607 for forwarded ARP packets. See the man page for arptables(8).
609 To compile it as a module, choose M here. If unsure, say N.
611 config IP_NF_ARP_MANGLE
612 tristate "ARP payload mangling"
613 depends on IP_NF_ARPTABLES
615 Allows altering the ARP packet payload: source and destination
616 hardware and network addresses.