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Doc: Add tag for links to RFCs

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Pavel Tvrdik 2016-09-29 18:08:40 +02:00
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@ -73,8 +73,8 @@ running on background which does the dynamic part of Internet routing, that is
it communicates with the other routers, calculates routing tables and sends them
to the OS kernel which does the actual packet forwarding. There already exist
other such routing daemons: routed (RIP only), GateD (non-free),
Zebra <HTMLURL URL="http://www.zebra.org"> and
MRTD <HTMLURL URL="http://sourceforge.net/projects/mrt">,
<HTMLURL URL="http://www.zebra.org" name="Zebra"> and
<HTMLURL URL="http://sourceforge.net/projects/mrt" name="MRTD">,
but their capabilities are limited and they are relatively hard to configure
and maintain.
@ -485,9 +485,9 @@ protocol rip {
used to validate route origination of BGP routes. A ROA table contains
ROA entries, each consist of a network prefix, a max prefix length and
an AS number. A ROA entry specifies prefixes which could be originated
by that AS number. ROA tables could be filled with data from RPKI (RFC
6480) or from public databases like Whois. ROA tables are examined by
<cf/roa_check()/ operator in filters.
by that AS number. ROA tables could be filled with data from RPKI (<rfc
id="6480">) or from public databases like Whois. ROA tables are
examined by <cf/roa_check()/ operator in filters.
Currently, there is just one option, <cf>roa <m/prefix/ max <m/num/ as
<m/num/</cf>, which can be used to populate the ROA table with static
@ -1270,9 +1270,9 @@ clist) or on clist and pair/quad set (returning true if there is an element of
the clist that is also a member of the pair/quad set).
<p>There is one operator related to ROA infrastructure - <cf/roa_check()/. It
examines a ROA table and does RFC 6483 route origin validation for a given
network prefix. The basic usage is <cf>roa_check(<m/table/)</cf>, which checks
current route (which should be from BGP to have AS_PATH argument) in the
examines a ROA table and does <rfc id="6483"> route origin validation for a
given network prefix. The basic usage is <cf>roa_check(<m/table/)</cf>, which
checks current route (which should be from BGP to have AS_PATH argument) in the
specified ROA table and returns ROA_UNKNOWN if there is no relevant ROA,
ROA_VALID if there is a matching ROA, or ROA_INVALID if there are some relevant
ROAs but none of them match. There is also an extended variant
@ -1434,11 +1434,12 @@ corresponding protocol sections.
<sect1>Introduction
<label id="babel-intro">
<p>The Babel protocol (RFC6126) is a loop-avoiding distance-vector routing
protocol that is robust and efficient both in ordinary wired networks and in
wireless mesh networks. Babel is conceptually very simple in its operation and
"just works" in its default configuration, though some configuration is possible
and in some cases desirable.
<p>The Babel protocol
(<rfc id="6126">) is a loop-avoiding distance-vector routing protocol that is
robust and efficient both in ordinary wired networks and in wireless mesh
networks. Babel is conceptually very simple in its operation and "just works"
in its default configuration, though some configuration is possible and in some
cases desirable.
<p>While the Babel protocol is dual stack (i.e., can carry both IPv4 and IPv6
routes over the same IPv6 transport), BIRD presently implements only the IPv6
@ -1580,14 +1581,10 @@ addresses and associated interfaces. When a session changes its state, these
protocols are notified and act accordingly (e.g. break an OSPF adjacency when
the BFD session went down).
<p>BIRD implements basic BFD behavior as defined in
RFC 5880<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc5880.txt">
(some advanced features like the echo mode or authentication are not implemented),
IP transport for BFD as defined in
RFC 5881<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc5881.txt"> and
RFC 5883<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc5883.txt">
and interaction with client protocols as defined in
RFC 5882<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc5882.txt">.
<p>BIRD implements basic BFD behavior as defined in <rfc id="5880"> (some
advanced features like the echo mode or authentication are not implemented), IP
transport for BFD as defined in <rfc id="5881"> and <rfc id="5883"> and
interaction with client protocols as defined in <rfc id="5882">.
<p>Note that BFD implementation in BIRD is currently a new feature in
development, expect some rough edges and possible UI and configuration changes
@ -1764,31 +1761,16 @@ the packet will travel through if it uses the particular route) in order to
avoid routing loops.
<p>BIRD supports all requirements of the BGP4 standard as defined in
RFC 4271<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4271.txt">
It also supports the community attributes
(RFC 1997<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc1997.txt">),
capability negotiation
(RFC 5492<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc5492.txt">),
MD5 password authentication
(RFC 2385<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc2385.txt">),
extended communities
(RFC 4360<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4360.txt">),
route reflectors
(RFC 4456<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4456.txt">),
graceful restart
(RFC 4724<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4724.txt">),
multiprotocol extensions
(RFC 4760<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4760.txt">),
4B AS numbers
(RFC 4893<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4893.txt">),
and 4B AS numbers in extended communities
(RFC 5668<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc5668.txt">).
<rfc id="4271"> It also supports the community attributes (<rfc id="1997">),
capability negotiation (<rfc id="5492">), MD5 password authentication (<rfc
id="2385">), extended communities (<rfc id="4360">), route reflectors (<rfc
id="4456">), graceful restart (<rfc id="4724">), multiprotocol extensions
(<rfc id="4760">), 4B AS numbers (<rfc id="4893">), and 4B AS numbers in
extended communities (<rfc id="5668">).
For IPv6, it uses the standard multiprotocol extensions defined in
RFC 4760<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4760.txt">
and applied to IPv6 according to
RFC 2545<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc2545.txt">.
<rfc id="4760"> and applied to IPv6 according to <rfc id="2545">.
<sect1>Route selection rules
<label id="bgp-route-select-rules">
@ -1938,20 +1920,20 @@ using the following configuration parameters:
<ref id="bfd" name="BFD"> section for details. Default: disabled.
<tag><label id="bgp-ttl-security">ttl security <m/switch/</tag>
Use GTSM (RFC 5082 - the generalized TTL security mechanism). GTSM
protects against spoofed packets by ignoring doc/bird.sgmlreceived packets with a
Use GTSM (<rfc id="5082"> - the generalized TTL security mechanism). GTSM
protects against spoofed packets by ignoring received packets with a
smaller than expected TTL. To work properly, GTSM have to be enabled on
both sides of a BGP session. If both <cf/ttl security/ and <cf/multihop/
options are enabled, <cf/multihop/ option should specify proper hop
value to compute expected TTL. Kernel support required: Linux: 2.6.34+
(IPv4), 2.6.35+ (IPv6), BSD: since long ago, IPv4 only. Note that full
(ICMP protection, for example) RFC 5082 support is provided by Linux
only. Default: disabled.
both sides of a BGP session. If both <cf/ttl security/ and
<cf/multihop/ options are enabled, <cf/multihop/ option should specify
proper hop value to compute expected TTL. Kernel support required:
Linux: 2.6.34+ (IPv4), 2.6.35+ (IPv6), BSD: since long ago, IPv4 only.
Note that full (ICMP protection, for example) <rfc id="5082"> support is
provided by Linux only. Default: disabled.
<tag><label id="bgp-pass">password <m/string/</tag>
Use this password for MD5 authentication of BGP sessions (RFC 2385).
When used on BSD systems, see also <cf/setkey/ option below. Default:
no authentication.
Use this password for MD5 authentication of BGP sessions (<rfc id="2385">). When
used on BSD systems, see also <cf/setkey/ option below. Default: no
authentication.
<tag><label id="bgp-setkey">setkey <m/switch/</tag>
On BSD systems, keys for TCP MD5 authentication are stored in the global
@ -1966,7 +1948,7 @@ using the following configuration parameters:
<tag><label id="bgp-passive">passive <m/switch/</tag>
Standard BGP behavior is both initiating outgoing connections and
accepting incoming connections. In passive modoc/bird.sgmlde, outgoing connections
accepting incoming connections. In passive mode, outgoing connections
are not initiated. Default: off.
<tag><label id="bgp-rr-client">rr client</tag>
@ -1985,11 +1967,11 @@ using the following configuration parameters:
Be a route server and treat the neighbor as a route server client.
A route server is used as a replacement for full mesh EBGP routing in
Internet exchange points in a similar way to route reflectors used in
IBGP routing. BIRD does not implement obsoleted RFC 1863, but uses
ad-hoc implementation, which behaves like plain EBGP but reduces
IBGP routing. BIRD does not implement obsoleted <rfc id="1863">, but
uses ad-hoc implementation, which behaves like plain EBGP but reduces
modifications to advertised route attributes to be transparent (for
example does not prepend its AS number to AS PATH attribute and keeps
MED attribute). Default: disabled.
example does not prepend its AS number to AS PATH attribute and
keeps MED attribute). Default: disabled.
<tag><label id="bgp-secondary">secondary <m/switch/</tag>
Usually, if an export filter rejects a selected route, no other route is
@ -2023,27 +2005,28 @@ using the following configuration parameters:
to keep BGP speakers synchronized. Sometimes (e.g., if BGP speaker
changes its import filter, or if there is suspicion of inconsistency) it
is necessary to do a new complete route exchange. BGP protocol extension
Route Refresh (RFC 2918) allows BGP speaker to request re-advertisement
of all routes from its neighbor. BGP protocol extension Enhanced Route
Refresh (RFC 7313) specifies explicit begin and end for such exchanges,
therefore the receiver can remove stale routes that were not advertised
during the exchange. This option specifies whether BIRD advertises these
capabilities and supports related procedures. Note that even when
disabled, BIRD can send route refresh requests. Default: on.
Route Refresh (<rfc id="2918">) allows BGP speaker to request
re-advertisement of all routes from its neighbor. BGP protocol
extension Enhanced Route Refresh (<rfc id="7313">) specifies explicit
begin and end for such exchanges, therefore the receiver can remove
stale routes that were not advertised during the exchange. This option
specifies whether BIRD advertises these capabilities and supports
related procedures. Note that even when disabled, BIRD can send route
refresh requests. Default: on.
<tag><label id="bgp-graceful-restart">graceful restart <m/switch/|aware</tag>
When a BGP speaker restarts or crashes, neighbors will discard all
received paths from the speaker, which disrupts packet forwarding even
when the forwarding plane of the speaker remains intact. RFC 4724
specifies an optional graceful restart mechanism to alleviate this
issue. This option controls the mechanism. It has three states:
Disabled, when no support is provided. Aware, when the graceful restart
support is announced and the support for restarting neighbors is
provided, but no local graceful restart is allowed (i.e. receiving-only
role). Enabled, when the full graceful restart support is provided
(i.e. both restarting and receiving role). Note that proper support for
local graceful restart requires also configuration of other protocols.
Default: aware.
when the forwarding plane of the speaker remains intact. <rfc
id="4724"> specifies an optional graceful restart mechanism to
alleviate this issue. This option controls the mechanism. It has three
states: Disabled, when no support is provided. Aware, when the graceful
restart support is announced and the support for restarting neighbors
is provided, but no local graceful restart is allowed (i.e.
receiving-only role). Enabled, when the full graceful restart
support is provided (i.e. both restarting and receiving role). Note
that proper support for local graceful restart requires also
configuration of other protocols. Default: aware.
<tag><label id="bgp-graceful-restart-time">graceful restart time <m/number/</tag>
The restart time is announced in the BGP graceful restart capability
@ -2052,15 +2035,15 @@ using the following configuration parameters:
120 seconds.
<tag><label id="bgp-interpret-communities">interpret communities <m/switch/</tag>
RFC 1997 demands that BGP speaker should process well-known communities
like no-export (65535, 65281) or no-advertise (65535, 65282). For
example, received route carrying a no-adverise community should not be
advertised to any of its neighbors. If this option is enabled (which is
by default), BIRD has such behavior automatically (it is evaluated when
a route is exported to the BGP protocol just before the export filter).
Otherwise, this integrated processing of well-known communities is
disabled. In that case, similar behavior can be implemented in the
export filter. Default: on.
<rfc id="1997"> demands that BGP speaker should process well-known
communities like no-export (65535, 65281) or no-advertise (65535,
65282). For example, received route carrying a no-adverise community
should not be advertised to any of its neighbors. If this option is
enabled (which is by default), BIRD has such behavior automatically (it
is evaluated when a route is exported to the BGP protocol just before
the export filter). Otherwise, this integrated processing of
well-known communities is disabled. In that case, similar behavior can
be implemented in the export filter. Default: on.
<tag><label id="bgp-enable-as4">enable as4 <m/switch/</tag>
BGP protocol was designed to use 2B AS numbers and was extended later to
@ -2085,10 +2068,10 @@ using the following configuration parameters:
<tag><label id="bgp-advertise-ipv4">advertise ipv4 <m/switch/</tag>
Advertise IPv4 multiprotocol capability. This is not a correct behavior
according to the strict interpretation of RFC 4760, but it is widespread
and required by some BGP implementations (Cisco and Quagga). This option
is relevant to IPv4 mode with enabled capability advertisement
only. Default: on.
according to the strict interpretation of <rfc id="4760">, but it is
widespread and required by some BGP implementations (Cisco and Quagga).
This option is relevant to IPv4 mode with enabled capability
advertisement only. Default: on.
<tag><label id="bgp-route-limit">route limit <m/number/</tag>
The maximal number of routes that may be imported from the protocol. If
@ -2152,16 +2135,16 @@ using the following configuration parameters:
BGP route selection algorithm is often viewed as a comparison between
individual routes (e.g. if a new route appears and is better than the
current best one, it is chosen as the new best one). But the proper
route selection, as specified by RFC 4271, cannot be fully implemented
in that way. The problem is mainly in handling the MED attribute. BIRD,
by default, uses an simplification based on individual route comparison,
which in some cases may lead to temporally dependent behavior (i.e. the
selection is dependent on the order in which routes appeared). This
option enables a different (and slower) algorithm implementing proper
RFC 4271 route selection, which is deterministic. Alternative way how to
get deterministic behavior is to use <cf/med metric/ option. This option
is incompatible with <ref id="dsc-table-sorted" name="sorted tables">.
Default: off.
route selection, as specified by <rfc id="4271">, cannot be fully
implemented in that way. The problem is mainly in handling the MED
attribute. BIRD, by default, uses an simplification based on individual
route comparison, which in some cases may lead to temporally dependent
behavior (i.e. the selection is dependent on the order in which routes
appeared). This option enables a different (and slower) algorithm
implementing proper <rfc id="4271"> route selection, which is
deterministic. Alternative way how to get deterministic behavior is to
use <cf/med metric/ option. This option is incompatible with <ref
id="dsc-table-sorted" name="sorted tables">. Default: off.
<tag><label id="bgp-igp-metric">igp metric <m/switch/</tag>
Enable comparison of internal distances to boundary routers during best
@ -2170,7 +2153,7 @@ using the following configuration parameters:
<tag><label id="bgp-prefer-older">prefer older <m/switch/</tag>
Standard route selection algorithm breaks ties by comparing router IDs.
This changes the behavior to prefer older routes (when both are external
and from different peer). For details, see RFC 5004. Default: off.
and from different peer). For details, see <rfc id="5004">. Default: off.
<tag><label id="bgp-default-med">default bgp_med <m/number/</tag>
Value of the Multiple Exit Discriminator to be used during route
@ -2210,8 +2193,8 @@ some of them (marked with `<tt/O/') are optional.
when a route is exported to an external BGP instance to ensure that the
attribute received from a neighboring AS is not propagated to other
neighboring ASes. A new value might be set in the export filter of an
external BGP instance. See RFC 4451<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4451.txt">
for further discussion of BGP MED attribute.
external BGP instance. See <rfc id="4451"> for further discussion of
BGP MED attribute.
<tag><label id="rta-bgp-origin">enum bgp_origin/</tag>
Origin of the route: either <cf/ORIGIN_IGP/ if the route has originated
@ -2580,15 +2563,13 @@ protocol kernel { # Secondary routing table
<label id="ospf-intro">
<p>Open Shortest Path First (OSPF) is a quite complex interior gateway
protocol. The current IPv4 version (OSPFv2) is defined in RFC 2328
<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc2328.txt">
and the current IPv6 version (OSPFv3) is defined in RFC 5340
<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc5340.txt">
It's a link state (a.k.a. shortest path first) protocol -- each router maintains
a database describing the autonomous system's topology. Each participating
router has an identical copy of the database and all routers run the same
algorithm calculating a shortest path tree with themselves as a root. OSPF
chooses the least cost path as the best path.
protocol. The current IPv4 version (OSPFv2) is defined in <rfc id="2328"> and
the current IPv6 version (OSPFv3) is defined in <rfc id="5340"> It's a link
state (a.k.a. shortest path first) protocol -- each router maintains a database
describing the autonomous system's topology. Each participating router has an
identical copy of the database and all routers run the same algorithm
calculating a shortest path tree with themselves as a root. OSPF chooses the
least cost path as the best path.
<p>In OSPF, the autonomous system can be split to several areas in order to
reduce the amount of resources consumed for exchanging the routing information
@ -2708,8 +2689,7 @@ protocol ospf &lt;name&gt; {
<descrip>
<tag><label id="ospf-rfc1583compat">rfc1583compat <M>switch</M></tag>
This option controls compatibility of routing table calculation with
RFC 1583 <htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc1583.txt">.
Default value is no.
<rfc id="1583">. Default value is no.
<tag><label id="ospf-instance-id">instance id <m/num/</tag>
When multiple OSPF protocol instances are active on the same links, they
@ -2726,9 +2706,8 @@ protocol ospf &lt;name&gt; {
that participates in the OSPF topology but does not allow transit
traffic. In OSPFv2, this is implemented by advertising maximum metric
for outgoing links. In OSPFv3, the stub router behavior is announced by
clearing the R-bit in the router LSA. See RFC 6987
<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc6987.txt"> for
details. Default value is no.
clearing the R-bit in the router LSA. See <rfc id="6987"> for details.
Default value is no.
<tag><label id="ospf-tick">tick <M>num</M></tag>
The routing table calculation and clean-up of areas' databases is not
@ -2839,10 +2818,9 @@ protocol ospf &lt;name&gt; {
You can specify alternative instance ID for the interface definition,
therefore it is possible to have several instances of that interface
with different options or even in different areas. For OSPFv2,
instance ID support is an extension (RFC 6549
<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc6549.txt">) and is
supposed to be set per-protocol. For OSPFv3, it is an integral feature.
with different options or even in different areas. For OSPFv2, instance
ID support is an extension (<rfc id="6549">) and is supposed to be set
per-protocol. For OSPFv3, it is an integral feature.
<tag><label id="ospf-virtual-link">virtual link <M>id</M> [instance <m/num/]</tag>
Virtual link to router with the router id. Virtual link acts as a
@ -3266,9 +3244,7 @@ time intervals or as an answer to a request) advertisement packets to connected
networks. These packets contain basic information about a local network (e.g. a
list of network prefixes), which allows network hosts to autoconfigure network
addresses and choose a default route. BIRD implements router behavior as defined
in RFC 4861<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4861.txt">
and also the DNS extensions from
RFC 6106<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc6106.txt">.
in <rfc id="4861"> and also the DNS extensions from <rfc id="6106">.
<sect1>Configuration
<label id="radv-config">
@ -3523,12 +3499,9 @@ counting to infinity is necessary, because it is slow. Due to infinity being 16,
you can't use RIP on networks where maximal distance is higher than 15
hosts.
<p>BIRD supports RIPv1
(RFC 1058<htmlurl url="http://www.rfc-editor.org/rfc/rfc1058.txt">),
RIPv2 (RFC 2453<htmlurl url="http://www.rfc-editor.org/rfc/rfc2453.txt">),
RIPng (RFC 2080<htmlurl url="http://www.rfc-editor.org/rfc/rfc2080.txt">),
and RIP cryptographic authentication (SHA-1 not implemented)
(RFC 4822<htmlurl url="http://www.rfc-editor.org/rfc/rfc4822.txt">).
<p>BIRD supports RIPv1 (<rfc id="1058">), RIPv2 (<rfc id="2453">), RIPng (<rfc
id="2080">), and RIP cryptographic authentication (SHA-1 not implemented)
(<rfc id="4822">).
<p>RIP is a very simple protocol, and it has a lot of shortcomings. Slow
convergence, big network load and inability to handle larger networks makes it
@ -3707,8 +3680,9 @@ protocol rip [&lt;name&gt;] {
compatibility with neighbors regardless of whether they use ttl
security.
For RIPng, TTL security is a standard behavior (required by RFC 2080)
and therefore default value is yes. For IPv4 RIP, default value is no.
For RIPng, TTL security is a standard behavior (required by <rfc
id="2080">) and therefore default value is yes. For IPv4 RIP, default
value is no.
<tag><label id="rip-iface-tx-class">tx class|dscp|priority <m/number/</tag>
These options specify the ToS/DiffServ/Traffic class/Priority of the

4
doc/sbase/dist/birddoc/html/mapping vendored
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@ -205,6 +205,10 @@
<htmlurl> "<A HREF=\"[URL]\">[NAME]</A>"
</htmlurl>
<rfc> "<A HREF=\"http://www.rfc-editor.org/info/rfc[ID]\">RFC [ID]</A>"
</rfc>
% ref modified to have an optional name field
<ref> + "<@@ref>[ID]\n"
"[NAME]</A>\n"

3
doc/sbase/dist/birddoc/latex2e/mapping vendored
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@ -238,6 +238,9 @@
<htmlurl> "\\href{[URL]}{[NAME]}"
</htmlurl>
<rfc> "\\href{http://www.rfc-editor.org/info/rfc[ID]}{RFC [ID]}"
</rfc>
<x>
</x>

6
doc/sbase/dtd/birddoc.dtd
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@ -99,7 +99,7 @@ anywhere else. <pavel@ucw.cz>
<!-- url added by HG; htmlurl added by esr -->
<!entity % xref
" label|ref|pageref|cite|url|htmlurl|ncite " >
" label|ref|pageref|cite|url|htmlurl|rfc|ncite " >
<!entity % inline
" (#pcdata | f| x| %emph; |sq| %xref | %index | file )* " >
@ -501,6 +501,10 @@ anywhere else. <pavel@ucw.cz>
url cdata #required
name cdata "&urlnam" >
<!element rfc - o empty>
<!attlist rfc
id cdata #required>
<!element pageref - o empty>
<!attlist pageref
id cdata #required>