.\" $OpenBSD: bgpd.conf.5,v 1.41 2004/11/19 10:06:33 claudio Exp $ .\" .\" Copyright (c) 2004 Claudio Jeker .\" Copyright (c) 2003, 2004 Henning Brauer .\" Copyright (c) 2002 Daniel Hartmeier .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .Dd March 10, 2004 .Dt BGPD.CONF 5 .Os .Sh NAME .Nm bgpd.conf .Nd Border Gateway Protocol daemon configuration file .Sh DESCRIPTION The .Xr bgpd 8 daemon implements the Border Gateway Protocol version 4 as described in RFC 1771. .Sh SECTIONS The .Nm config file is divided into four main sections. .Bl -tag -width xxxx .It Sy Macros User-defined variables may be defined and used later, simplifying the configuration file. .It Sy Global Configuration Global settings for .Xr bgpd 8 . .It Sy Neighbors and Groups .Xr bgpd 8 establishes sessions with .Em neighbors . The neighbor definition and properties are set in this section, as well as grouping neighbors for the ease of configuration. .It Sy Filter Filter rules for incoming and outgoing .Em UPDATES . .El .Pp With the exception of macros, the sections should be grouped and appear in .Nm in the order shown above. .Sh MACROS Much like .Xr cpp 1 or .Xr m4 1 , macros can be defined that will later be expanded in context. Macro names must start with a letter, and may contain letters, digits and underscores. Macro names may not be reserved words (for example, .Ic AS , .Ic neighbor , or .Ic group ) . Macros are not expanded inside quotes. .Pp For example, .Bd -literal -offset indent peer1="1.2.3.4" neighbor $peer1 { remote-as 65001 } .Ed .Sh GLOBAL CONFIGURATION There are quite a few settings that affect the operation of the .Xr bgpd 8 daemon globally. .Pp .Bl -tag -width Ds -compact .It Ic AS Ar as-number Set the local .Em autonomous system number to .Ar as-number . The AS numbers are assigned by local RIRs, such as .Pp .Bl -tag -width xxxxxxxx -compact .It APNIC for the Asia Pacific region, .It ARIN for North America, parts of the Caribbean and Africa, .It LACNIC for Latin America and Caribbean, and .It RIPE NCC for Europe, the Middle East and parts of Asia and Africa. .El .Pp For example, .Bd -literal -offset indent AS 65001 .Ed .Pp sets the local AS to 65001. .Pp .It Xo .Ic dump .Pq Ic table Ns \&| Ns Ic table-mp .Ar file Op Ar timeout .Xc .It Xo .Ic dump .Pq Ic all Ns \&| Ns Ic updates .Pq Ic in Ns \&| Ns Ic out .Ar file Op Ar timeout .Xc Dump the RIB, a.k.a. the .Em routing information base , and all BGP messages in Multi-threaded Routing Toolkit (MRT) format. Dumping the RIB is normally an expensive operation, but it should not influence the session handling. Excessive dumping may result in delayed update processing. .Pp For example, the following will dump the entire table to the .Xr strftime 3 Ns -expanded filename. The .Ic table-mp format is multi-protocol capable but often not supported by 3rd-party tools. The timeout is optional: .Bd -literal -offset indent dump table "/tmp/rib-dump-%H%M" 300 .Ed .Pp Similar to the table dump, but this time all BGP messages and .Em state transitions will be dumped to the specified file: .Bd -literal -offset indent dump all in "/tmp/all-in-%H%M" 300 .Ed .Pp As before, but only the .Em UPDATE messages will be dumped to the file: .Bd -literal -offset indent dump updates in "/tmp/updates-in-%H%M" 300 .Ed .Pp It is also possible to dump outgoing messages: .Bd -literal -offset indent dump all out "/tmp/all-out-%H%M" 300 # or dump updates out "/tmp/updates-out-%H%M" 300 .Ed .Pp .It Xo .Ic fib-update .Pq Ic yes Ns \&| Ns Ic no .Xc If set to .Ic no , do not update the Forward Information Base, a.k.a. the kernel routing table. The default is .Ic yes . .Pp .It Ic holdtime Ar seconds Set the holdtime in seconds. The holdtime is reset to its initial value every time either a .Em KEEPALIVE or an .Em UPDATE message is received from the neighbor. If the holdtime expires the session is dropped. The default is 90 seconds. Neighboring systems negotiate the holdtime used when the connection is established in the .Em OPEN messages. Each neighbor announces its configured holdtime; the smaller one is then agreed upon. .Pp .It Ic holdtime min Ar seconds The minimal accepted holdtime in seconds. This value must be greater than or equal to 3. .Pp .It Ic listen on Ar address Specify the local IP address .Xr bgpd 8 should listen on. .Bd -literal -offset indent listen on 127.0.0.1 .Ed .Pp .It Ic log updates Log received and sent updates. .Pp .It Xo .Ic network .Ar address Ns Li / Ns Ar prefix .Op Ic set ...\& .Xc Announce the specified network as belonging to our AS. .Bd -literal -offset indent network 192.168.7.0/24 .Ed .Pp It is possible to set default .Em AS path attributes per .Ic network statement: .Bd -literal -offset indent network 192.168.7.0/24 set localpref 220 .Ed .Pp See also the .Sx ATTRIBUTE SET section. .Pp .It Xo .Ic rde .Ic route-age .Pq Ic ignore Ns \&| Ns Ic evaluate .Xc If set to .Ic evaluate , the best path selection will not only be based on the path attributes but also on the age of the route. In this case the decision process is no longer deterministic. The default is .Ic ignore . .Pp .It Xo .Ic route-collector .Pq Ic yes Ns \&| Ns Ic no .Xc If set to .Ic yes , the route selection process is turned off. The default is .Ic no . .Pp .It Ic router-id Ar address Set the router ID to the given IP address, which must be local to the machine. .Bd -literal -offset indent router-id 10.0.0.1 .Ed .Pp If not given, the BGP ID is determined as the biggest IP address assigned to the local machine. .El .Sh NEIGHBORS AND GROUPS .Xr bgpd 8 establishes TCP connections to other BGP speakers called .Em neighbors . Each neighbor is specified by a .Ic neighbor section, which allows properties to be set specifially for that neighbor: .Bd -literal -offset indent neighbor 10.0.0.2 { remote-as 65002 descr "a neighbor" } .Ed .Pp Multiple neighbors can be grouped together by a .Ic group section. Each .Ic neighbor section within the .Ic group section inherits all properties from its group: .Bd -literal -offset indent group "peering AS65002" { remote-as 65002 neighbor 10.0.0.2 { descr "AS65002-p1" } neighbor 10.0.0.3 { descr "AS65002-p2" } } .Ed .Pp Instead of the neighbor's IP address, an address/netmask pair may be given: .Bd -literal -offset indent neighbor 10.0.0.0/8 .Ed .Pp In this case, the neighbor specification becomes a .Em template , and if a neighbor connects from an IP address within the given network, the template is .Em cloned , inheriting everything from the template but the remote address, which is replaced by the connecting neighbor's address. With a template specification it is valid to omit .Ic remote-as ; .Xr bgpd 8 will then accept any AS the neighbor presents in the .Em OPEN message. .Pp There are several neighbor properties: .Pp .Bl -tag -width Ds -compact .It Xo .Ic announce .Sm off .Po Ic all \*(Ba none \*(Ba .Ic self \*(Ba default-route Pc .Sm on .Xc If set to .Ic none , no .Em UPDATE messages will be sent to the neighbor. If set to .Ic default-route , only the default route will be announced to the neighbor. If set to .Ic all , all generated .Em UPDATE messages will be sent to the neighbor. This is usually used for .Em transit AS's and .Em IBGP peers. The default value for .Em EBGP peers is .Ic self , which limits the sent .Em UPDATE messages to announcements of the local AS. The default for IBGP peers is .Ic all . .Pp .It Ic descr Ar description Add a description. The description is used when logging neighbor events and in status reports, etc., and has no further meaning to .Xr bgpd 8 . .Pp .It Xo .Ic dump .Pq Ic all Ns \&| Ns Ic updates .Pq Ic in Ns \&| Ns Ic out .Ar file Op Ar timeout .Xc Do a peer specific MRT dump. Peer specific dumps are limited to .Ic all and .Ic updates . See also the .Ic dump section in .Sx GLOBAL CONFIGURATION . .Pp .It Xo .Ic enforce neighbor-as .Pq Ic yes Ns \&| Ns Ic no .Xc If set to .Ic yes , .Em AS paths whose .Em leftmost AS is not equal to the .Em remote AS of the neighbor are rejected and a .Em NOTIFICATION is sent back. The default value for IBGP peers is .Ic no otherwise the default is .Ic yes . .Pp .It Ic holdtime Ar seconds Set the holdtime in seconds. Inherited from the global configuration if not given. .Pp .It Ic holdtime min Ar seconds Set the minimal acceptable holdtime. Inherited from the global configuration if not given. .Pp .It Xo .Ic ipsec .Pq Ic ah Ns \&| Ns Ic esp .Pq Ic in Ns \&| Ns Ic out .Ic spi Ar spi-number authspec Op Ar encspec .Xc Enable IPsec with static keying. There must be at least two .Ic ipsec statements per peer with manual keying, one per direction. .Ar authspec specifies the authentication algorithm and key. It can be .Bd -literal -offset indent sha1 md5 .Ed .Pp .Ar encspec specifies the encryption algorithm and key. .Ic ah does not support encryption. With .Ic esp , encryption is optional. .Ar encspec can be .Bd -literal -offset indent 3des 3des-cbc aes aes-128-cbc .Ed .Pp Keys must be given in hexadecimal format. .Pp .It Xo .Ic ipsec .Pq Ic ah Ns \&| Ns Ic esp .Ic ike .Xc Enable IPsec with dynamic keying. In this mode, .Xr bgpd 8 sets up the flows, and a key management daemon such as .Xr isakmpd 8 is responsible for managing the session keys. With .Xr isakmpd 8 , it is sufficient to copy the peer's public key, found in .Pa /etc/isakmpd/private/local.pub , to the local machine. It must be stored in a file named after the peer's IP address and must be stored in .Pa /etc/isakmpd/pubkeys/ipv4/ . The local public key must be copied to the peer in the same way. As .Xr bgpd 8 manages the flows on its own, it is sufficient to restrict .Xr isakmpd 8 to only take care of keying by specifying the flags .Fl Ka . This can be done in .Xr rc.conf.local 8 . After starting the .Xr isakmpd 8 and .Xr bgpd 8 daemons on both sides, the session should be established. .Pp .It Ic local-address Ar address When .Xr bgpd 8 initiates the TCP connection to the neighbor system, it normally does not bind to a specific IP address. If a .Ic local-address is given, .Xr bgpd 8 binds to this address first. .Pp .It Ic max-prefix Ar number Limit the amount of prefixes received. No such limit is imposed by default. .Pp .It Ic multihop Ar hops Neighbors not in the same AS as the local .Xr bgpd 8 normally have to be directly connected to the local machine. If this is not the case, the .Ic multihop statement defines the maximum hops the neighbor may be away. .Pp .It Ic passive Do not attempt to actively open a TCP connection to the neighbor system. .Pp .It Ic remote-as Ar as-number Set the AS number of the remote system. .Pp .It Ic route-reflector Op Ar address Act as an RFC 2796 .Em route-reflector for this neighbor. An optional cluster ID can be specified; otherwise the BGP ID will be used. .Pp .It Ic set Ar attribute ... Set the .Em AS path attributes to some default per .Ic neighbor or .Ic group block: .Bd -literal -offset indent set localpref 300 .Ed .Pp See also the .Sx ATTRIBUTE SET section. .Pp .It Ic tcp md5sig password Ar secret .It Ic tcp md5sig key Ar secret Enable TCP MD5 signatures per RFC 2385. The shared secret can either be given as a password or hexadecimal key. .Bd -literal -offset indent tcp md5sig password mekmidasdigoat tcp md5sig key deadbeef .Ed .El .Sh FILTER .Xr bgpd 8 has the ability to .Ic allow and .Ic deny .Em UPDATES based on .Em prefix or .Em AS path attributes . In addition, .Em UPDATES may also be modified by filter rules. .Pp For each .Em UPDATE processed by the filter, the filter rules are evaluated in sequential order, from first to last. The last matching .Ic allow or .Ic deny rule decides what action is taken. .Pp The following actions can be used in the filter: .Bl -tag -width xxxxxxxx .It Ic allow The .Em UPDATE is passed. .It Ic deny The .Em UPDATE is blocked. .It Ic match Apply the filter attribute set without influencing the filter decision. .El .Sh PARAMETERS The rule parameters specify the .Em UPDATES to which a rule applies. An .Em UPDATE always comes from, or goes to, one neighbor. Most parameters are optional, but each can appear at most once per rule. If a parameter is specified, the rule only applies to packets with matching attributes. .Pp .Bl -tag -width Ds -compact .It Ar as-type as-number This rule applies only to .Em UPDATES where the .Em AS path matches. The .Ar as-number is matched against a part of the .Em AS path specified by the .Ar as-type . .Ar as-type is one of the following operators: .Pp .Bl -tag -width transmit-as -compact .It Ic AS (any part) .It Ic source-as (rightmost AS number) .It Ic transit-as (all but the rightmost AS number) .El .Pp Multiple .Ar as-number entries for a given type or .Ar as-type as-number entries may also be specified, separated by commas or whitespace, if enclosed in curly brackets: .Bd -literal -offset indent deny from any AS { 1, 2, 3 } deny from any { AS 1, source-as 2, transit-as 3 } deny from any { AS { 1, 2, 3 }, source-as 4, transit-as 5 } .Ed .Pp .It Xo .Ic community .Ar as-number Ns Li \&: Ns Ar local .Xc .It Ic community Ar name This rule applies only to .Em UPDATES where the .Ic community path attribute is present and matches. Communities are specified as .Ar as-number Ns Li : Ns Ar local , where .Ar as-number is an AS number and .Ar local is a locally significant number between zero and .Li 65535 . Both .Ar as-number and .Ar local may be set to .Sq * to do wildcard matching. Alternatively, well-known communities may be given by name instead and include .Ic NO_EXPORT , .Ic NO_ADVERTISE , .Ic NO_EXPORT_SUBCONFED , and .Ic NO_PEER . .Pp .It Xo .Pq Ic from Ns \&| Ns Ic to .Ar peer .Xc This rule applies only to .Em UPDATES coming from, or going to, this particular neighbor. This parameter must be specified. .Ar peer is one of the following: .Pp .Bl -tag -width "group descr" -compact .It Ic any Any neighbor will be matched. .It Ar address Neighbors with this address will be matched. .It Ic group Ar descr Neighbors in this group will be matched. .El .Pp Multiple .Ar peer entries may also be specified, separated by commas or whitespace, if enclosed in curly brackets: .Bd -literal -offset indent deny from { 128.251.16.1, 251.128.16.2, group hojo } .Ed .Pp .It Xo .Ic prefix .Ar address Ns Li / Ns Ar len .Xc This rule applies only to .Em UPDATES for the specified prefix. .Pp Multiple .Ar address Ns Li / Ns Ar len entries may be specified, separated by commas or whitespace, if enclosed in curly brackets: .Bd -literal -offset indent deny from any prefix { 192.168.0.0/16, 10.0.0.0/8 } .Ed .Pp Multiple lists can also be specified, which is useful for macro expansion: .Bd -literal -offset indent good="{ 192.168.0.0/16, 172.16.0.0/12, 10.0.0.0/8 }" bad="{ 224.0.0.0/4, 240.0.0.0/4 }" ugly="{ 127.0.0.1/8, 169.254.0.0/16 }" deny from any prefix { $good $bad $ugly } .Ed .Pp .It Ic prefixlen Ar range This rule applies only to .Em UPDATES for prefixes where the prefixlen matches. Prefix length ranges are specified by using these operators: .Bd -literal -offset indent = (equal) != (unequal) < (less than) <= (less than or equal) > (greater than) >= (greater than or equal) - (range including boundaries) >< (except range) .Ed .Pp >< and - are binary operators (they take two arguments). For instance, to match all prefix lengths >= 8 and <= 12, and hence the CIDR netmasks 8, 9, 10, 11 and 12: .Bd -literal -offset indent prefixlen 8-12 .Ed .Pp Or, to match all prefix lengths < 8 or > 12, and hence the CIDR netmasks 0\-7 and 13\-32: .Bd -literal -offset indent prefixlen 8><12 .Ed .Pp .Ic prefixlen can be used together with .Ic prefix . .Pp This will match all prefixes in the 10.0.0.0/8 netblock with netmasks longer than 16: .Bd -literal -offset indent prefix 10.0.0.0/8 prefixlen > 16 .Ed .Pp .It Ic quick If an .Em UPDATE matches a rule which has the .Ic quick option set, this rule is considered the last matching rule, and evaluation of subsequent rules is skipped. .Pp .It Ic set Ar attribute ... All matching rules can set the .Em AS path attributes to some default. The set of every matching rule is applied, not only the last matching one. See also the following section. .El .Sh ATTRIBUTE SET .Em AS path attributes can be modified with .Ic set . .Pp .Ic set can be used on .Ic network statements, in .Ic neighbor or .Ic group blocks, and on filter rules. Attribute sets can be expressed as lists. .Pp The following attributes can be modified: .Pp .Bl -tag -width Ds -compact .It Xo .Ic community .Ar as-number Ns Li : Ns Ar local .Xc .It Ic community Ar name Set the .Em COMMUNITIES AS path attribute. Communities are specified as .Ar as-number Ns Li : Ns Ar local , where .Ar as-number is an AS number and .Ar local is a locally-significant number between zero and .Li 0xffff . Alternately, well-known communities may be specified by name: .Ic NO_EXPORT , .Ic NO_ADVERTISE , or .Ic NO_EXPORT_SUBCONFED . .Pp .It Ic localpref Ar number Set the .Em LOCAL_PREF AS path attribute. .Pp .It Ic med Ar number Set the .Em MULTI_EXIT_DISC AS path attribute. .Pp .It Xo .Ic nexthop .Po Ar address Ns \&| Ns .Ic blackhole Ns \&| Ns Ic reject Pc .Xc Set the .Em NEXTHOP AS path attribute to a different nexthop address, or use blackhole or reject routes. .Bd -literal -offset indent set nexthop 192.168.0.1 set nexthop blackhole set nexthop reject .Ed .Pp .It Ic pftable Ar table Add the prefix in the update to the specified .Xr pf 4 radix table, regardless of whether or not the path was selected for routing. This option may be useful in building realtime blacklists. .Pp .It Ic prepend-neighbor Ar number Prepend the neighbor's AS .Ar number times to the .Em AS path . .Pp .It Ic prepend-self Ar number Prepend the local AS .Ar number times to the .Em AS path . .El .Sh FILES .Bl -tag -width "/etc/bgpd.conf" -compact .It Pa /etc/bgpd.conf .Xr bgpd 8 configuration file .El .Sh SEE ALSO .Xr strftime 3 , .Xr ipsec 4 , .Xr pf 4 , .Xr tcp 4 , .Xr bgpctl 8 , .Xr bgpd 8 , .Xr ipsecadm 8 , .Xr isakmpd 8 , .Xr rc.conf.local 8 .Sh HISTORY The .Nm file format first appeared in .Ox 3.5 .