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 If you are running the Amanda backup package <http://www.amanda.org/>
147 on this machine or machines that will be MASQUERADED through this
148 machine, then you may want to enable this feature. This allows the
149 connection tracking and natting code to allow the sub-channels that
150 Amanda requires for communication of the backup data, messages and
153 To compile it as a module, choose M here. If unsure, say Y.
156 tristate 'PPTP protocol support'
157 depends on IP_NF_CONNTRACK
159 This module adds support for PPTP (Point to Point Tunnelling
160 Protocol, RFC2637) connection tracking and NAT.
162 If you are running PPTP sessions over a stateful firewall or NAT
163 box, you may want to enable this feature.
165 Please note that not all PPTP modes of operation are supported yet.
166 For more info, read top of the file
167 net/ipv4/netfilter/ip_conntrack_pptp.c
169 If you want to compile it as a module, say M here and read
170 Documentation/modules.txt. If unsure, say `N'.
173 tristate 'H.323 protocol support'
174 depends on IP_NF_CONNTRACK
176 H.323 is a VoIP signalling protocol from ITU-T. As one of the most
177 important VoIP protocols, it is widely used by voice hardware and
178 software including voice gateways, IP phones, Netmeeting, OpenPhone,
181 With this module you can support H.323 on a connection tracking/NAT
184 This module supports RAS, Fast-start, H.245 tunnelling, RTP/RTCP
185 and T.120 based data and applications including audio, video, FAX,
186 chat, whiteboard, file transfer, etc. For more information, please
187 see http://nath323.sourceforge.net/.
189 If you want to compile it as a module, say 'M' here and read
190 Documentation/modules.txt. If unsure, say 'N'.
193 tristate "IP Userspace queueing via NETLINK (OBSOLETE)"
195 Netfilter has the ability to queue packets to user space: the
196 netlink device can be used to access them using this driver.
198 This option enables the old IPv4-only "ip_queue" implementation
199 which has been obsoleted by the new "nfnetlink_queue" code (see
200 CONFIG_NETFILTER_NETLINK_QUEUE).
202 To compile it as a module, choose M here. If unsure, say N.
204 config IP_NF_IPTABLES
205 tristate "IP tables support (required for filtering/masq/NAT)"
206 depends on NETFILTER_XTABLES
208 iptables is a general, extensible packet identification framework.
209 The packet filtering and full NAT (masquerading, port forwarding,
210 etc) subsystems now use this: say `Y' or `M' here if you want to use
213 To compile it as a module, choose M here. If unsure, say N.
216 config IP_NF_MATCH_IPRANGE
217 tristate "IP range match support"
218 depends on IP_NF_IPTABLES
220 This option makes possible to match IP addresses against IP address
223 To compile it as a module, choose M here. If unsure, say N.
225 config IP_NF_MATCH_TOS
226 tristate "TOS match support"
227 depends on IP_NF_IPTABLES
229 TOS matching allows you to match packets based on the Type Of
230 Service fields of the IP packet.
232 To compile it as a module, choose M here. If unsure, say N.
234 config IP_NF_MATCH_RECENT
235 tristate "recent match support"
236 depends on IP_NF_IPTABLES
238 This match is used for creating one or many lists of recently
239 used addresses and then matching against that/those list(s).
241 Short options are available by using 'iptables -m recent -h'
242 Official Website: <http://snowman.net/projects/ipt_recent/>
244 To compile it as a module, choose M here. If unsure, say N.
246 config IP_NF_MATCH_ECN
247 tristate "ECN match support"
248 depends on IP_NF_IPTABLES
250 This option adds a `ECN' match, which allows you to match against
251 the IPv4 and TCP header ECN fields.
253 To compile it as a module, choose M here. If unsure, say N.
255 config IP_NF_MATCH_DSCP
256 tristate "DSCP match support"
257 depends on IP_NF_IPTABLES
259 This option adds a `DSCP' match, which allows you to match against
260 the IPv4 header DSCP field (DSCP codepoint).
262 The DSCP codepoint can have any value between 0x0 and 0x4f.
264 To compile it as a module, choose M here. If unsure, say N.
266 config IP_NF_MATCH_AH
267 tristate "AH match support"
268 depends on IP_NF_IPTABLES
270 This match extension allows you to match a range of SPIs
271 inside AH header of IPSec packets.
273 To compile it as a module, choose M here. If unsure, say N.
275 config IP_NF_MATCH_TTL
276 tristate "TTL match support"
277 depends on IP_NF_IPTABLES
279 This adds CONFIG_IP_NF_MATCH_TTL option, which enabled the user
280 to match packets by their TTL value.
282 To compile it as a module, choose M here. If unsure, say N.
284 config IP_NF_MATCH_OWNER
285 tristate "Owner match support"
286 depends on IP_NF_IPTABLES
288 Packet owner matching allows you to match locally-generated packets
289 based on who created them: the user, group, process or session.
291 To compile it as a module, choose M here. If unsure, say N.
293 config IP_NF_MATCH_ADDRTYPE
294 tristate 'address type match support'
295 depends on IP_NF_IPTABLES
297 This option allows you to match what routing thinks of an address,
298 eg. UNICAST, LOCAL, BROADCAST, ...
300 If you want to compile it as a module, say M here and read
301 <file:Documentation/modules.txt>. If unsure, say `N'.
303 config IP_NF_MATCH_HASHLIMIT
304 tristate 'hashlimit match support'
305 depends on IP_NF_IPTABLES
307 This option adds a new iptables `hashlimit' match.
309 As opposed to `limit', this match dynamically crates a hash table
310 of limit buckets, based on your selection of source/destination
311 ip addresses and/or ports.
313 It enables you to express policies like `10kpps for any given
314 destination IP' or `500pps from any given source IP' with a single
317 # `filter', generic and specific targets
319 tristate "Packet filtering"
320 depends on IP_NF_IPTABLES
322 Packet filtering defines a table `filter', which has a series of
323 rules for simple packet filtering at local input, forwarding and
324 local output. See the man page for iptables(8).
326 To compile it as a module, choose M here. If unsure, say N.
328 config IP_NF_TARGET_REJECT
329 tristate "REJECT target support"
330 depends on IP_NF_FILTER
332 The REJECT target allows a filtering rule to specify that an ICMP
333 error should be issued in response to an incoming packet, rather
334 than silently being dropped.
336 To compile it as a module, choose M here. If unsure, say N.
338 config IP_NF_TARGET_LOG
339 tristate "LOG target support"
340 depends on IP_NF_IPTABLES
342 This option adds a `LOG' target, which allows you to create rules in
343 any iptables table which records the packet header to the syslog.
345 To compile it as a module, choose M here. If unsure, say N.
347 config IP_NF_TARGET_ULOG
348 tristate "ULOG target support"
349 depends on IP_NF_IPTABLES
352 This option enables the old IPv4-only "ipt_ULOG" implementation
353 which has been obsoleted by the new "nfnetlink_log" code (see
354 CONFIG_NETFILTER_NETLINK_LOG).
356 This option adds a `ULOG' target, which allows you to create rules in
357 any iptables table. The packet is passed to a userspace logging
358 daemon using netlink multicast sockets; unlike the LOG target
359 which can only be viewed through syslog.
361 The apropriate userspace logging daemon (ulogd) may be obtained from
362 <http://www.gnumonks.org/projects/ulogd/>
364 To compile it as a module, choose M here. If unsure, say N.
366 config IP_NF_TARGET_TCPMSS
367 tristate "TCPMSS target support"
368 depends on IP_NF_IPTABLES
370 This option adds a `TCPMSS' target, which allows you to alter the
371 MSS value of TCP SYN packets, to control the maximum size for that
372 connection (usually limiting it to your outgoing interface's MTU
375 This is used to overcome criminally braindead ISPs or servers which
376 block ICMP Fragmentation Needed packets. The symptoms of this
377 problem are that everything works fine from your Linux
378 firewall/router, but machines behind it can never exchange large
380 1) Web browsers connect, then hang with no data received.
381 2) Small mail works fine, but large emails hang.
382 3) ssh works fine, but scp hangs after initial handshaking.
384 Workaround: activate this option and add a rule to your firewall
387 iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN \
388 -j TCPMSS --clamp-mss-to-pmtu
390 To compile it as a module, choose M here. If unsure, say N.
392 # NAT + specific targets
395 depends on IP_NF_IPTABLES && IP_NF_CONNTRACK
397 The Full NAT option allows masquerading, port forwarding and other
398 forms of full Network Address Port Translation. It is controlled by
399 the `nat' table in iptables: see the man page for iptables(8).
401 To compile it as a module, choose M here. If unsure, say N.
403 config IP_NF_NAT_NEEDED
405 depends on IP_NF_NAT != n
408 config IP_NF_TARGET_MASQUERADE
409 tristate "MASQUERADE target support"
412 Masquerading is a special case of NAT: all outgoing connections are
413 changed to seem to come from a particular interface's address, and
414 if the interface goes down, those connections are lost. This is
415 only useful for dialup accounts with dynamic IP address (ie. your IP
416 address will be different on next dialup).
418 To compile it as a module, choose M here. If unsure, say N.
420 config IP_NF_TARGET_REDIRECT
421 tristate "REDIRECT target support"
424 REDIRECT is a special case of NAT: all incoming connections are
425 mapped onto the incoming interface's address, causing the packets to
426 come to the local machine instead of passing through. This is
427 useful for transparent proxies.
429 To compile it as a module, choose M here. If unsure, say N.
431 config IP_NF_TARGET_NETMAP
432 tristate "NETMAP target support"
435 NETMAP is an implementation of static 1:1 NAT mapping of network
436 addresses. It maps the network address part, while keeping the host
437 address part intact. It is similar to Fast NAT, except that
438 Netfilter's connection tracking doesn't work well with Fast NAT.
440 To compile it as a module, choose M here. If unsure, say N.
442 config IP_NF_TARGET_SAME
443 tristate "SAME target support"
446 This option adds a `SAME' target, which works like the standard SNAT
447 target, but attempts to give clients the same IP for all connections.
449 To compile it as a module, choose M here. If unsure, say N.
451 config IP_NF_NAT_SNMP_BASIC
452 tristate "Basic SNMP-ALG support (EXPERIMENTAL)"
453 depends on EXPERIMENTAL && IP_NF_NAT
456 This module implements an Application Layer Gateway (ALG) for
457 SNMP payloads. In conjunction with NAT, it allows a network
458 management system to access multiple private networks with
459 conflicting addresses. It works by modifying IP addresses
460 inside SNMP payloads to match IP-layer NAT mapping.
462 This is the "basic" form of SNMP-ALG, as described in RFC 2962
464 To compile it as a module, choose M here. If unsure, say N.
468 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
469 default IP_NF_NAT if IP_NF_IRC=y
470 default m if IP_NF_IRC=m
472 # If they want FTP, set to $CONFIG_IP_NF_NAT (m or y),
473 # or $CONFIG_IP_NF_FTP (m or y), whichever is weaker. Argh.
476 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
477 default IP_NF_NAT if IP_NF_FTP=y
478 default m if IP_NF_FTP=m
480 config IP_NF_NAT_TFTP
482 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
483 default IP_NF_NAT if IP_NF_TFTP=y
484 default m if IP_NF_TFTP=m
486 config IP_NF_NAT_AMANDA
488 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
489 default IP_NF_NAT if IP_NF_AMANDA=y
490 default m if IP_NF_AMANDA=m
492 config IP_NF_NAT_PPTP
494 depends on IP_NF_NAT!=n && IP_NF_PPTP!=n
495 default IP_NF_NAT if IP_NF_PPTP=y
496 default m if IP_NF_PPTP=m
498 config IP_NF_NAT_H323
500 depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
501 default IP_NF_NAT if IP_NF_H323=y
502 default m if IP_NF_H323=m
504 # mangle + specific targets
506 tristate "Packet mangling"
507 depends on IP_NF_IPTABLES
509 This option adds a `mangle' table to iptables: see the man page for
510 iptables(8). This table is used for various packet alterations
511 which can effect how the packet is routed.
513 To compile it as a module, choose M here. If unsure, say N.
515 config IP_NF_TARGET_TOS
516 tristate "TOS target support"
517 depends on IP_NF_MANGLE
519 This option adds a `TOS' target, which allows you to create rules in
520 the `mangle' table which alter the Type Of Service field of an IP
521 packet prior to routing.
523 To compile it as a module, choose M here. If unsure, say N.
525 config IP_NF_TARGET_ECN
526 tristate "ECN target support"
527 depends on IP_NF_MANGLE
529 This option adds a `ECN' target, which can be used in the iptables mangle
532 You can use this target to remove the ECN bits from the IPv4 header of
533 an IP packet. This is particularly useful, if you need to work around
534 existing ECN blackholes on the internet, but don't want to disable
535 ECN support in general.
537 To compile it as a module, choose M here. If unsure, say N.
539 config IP_NF_TARGET_DSCP
540 tristate "DSCP target support"
541 depends on IP_NF_MANGLE
543 This option adds a `DSCP' match, which allows you to match against
544 the IPv4 header DSCP field (DSCP codepoint).
546 The DSCP codepoint can have any value between 0x0 and 0x4f.
548 To compile it as a module, choose M here. If unsure, say N.
550 config IP_NF_TARGET_TTL
551 tristate 'TTL target support'
552 depends on IP_NF_MANGLE
554 This option adds a `TTL' target, which enables the user to modify
555 the TTL value of the IP header.
557 While it is safe to decrement/lower the TTL, this target also enables
558 functionality to increment and set the TTL value of the IP header to
559 arbitrary values. This is EXTREMELY DANGEROUS since you can easily
560 create immortal packets that loop forever on the network.
562 To compile it as a module, choose M here. If unsure, say N.
564 config IP_NF_TARGET_CLUSTERIP
565 tristate "CLUSTERIP target support (EXPERIMENTAL)"
566 depends on IP_NF_MANGLE && EXPERIMENTAL
567 depends on (IP_NF_CONNTRACK && IP_NF_CONNTRACK_MARK) || (NF_CONNTRACK_MARK && NF_CONNTRACK_IPV4)
569 The CLUSTERIP target allows you to build load-balancing clusters of
570 network servers without having a dedicated load-balancing
571 router/server/switch.
573 To compile it as a module, choose M here. If unsure, say N.
575 # raw + specific targets
577 tristate 'raw table support (required for NOTRACK/TRACE)'
578 depends on IP_NF_IPTABLES
580 This option adds a `raw' table to iptables. This table is the very
581 first in the netfilter framework and hooks in at the PREROUTING
584 If you want to compile it as a module, say M here and read
585 <file:Documentation/modules.txt>. If unsure, say `N'.
588 config IP_NF_ARPTABLES
589 tristate "ARP tables support"
590 depends on NETFILTER_XTABLES
592 arptables is a general, extensible packet identification framework.
593 The ARP packet filtering and mangling (manipulation)subsystems
594 use this: say Y or M here if you want to use either of those.
596 To compile it as a module, choose M here. If unsure, say N.
598 config IP_NF_ARPFILTER
599 tristate "ARP packet filtering"
600 depends on IP_NF_ARPTABLES
602 ARP packet filtering defines a table `filter', which has a series of
603 rules for simple ARP packet filtering at local input and
604 local output. On a bridge, you can also specify filtering rules
605 for forwarded ARP packets. See the man page for arptables(8).
607 To compile it as a module, choose M here. If unsure, say N.
609 config IP_NF_ARP_MANGLE
610 tristate "ARP payload mangling"
611 depends on IP_NF_ARPTABLES
613 Allows altering the ARP packet payload: source and destination
614 hardware and network addresses.