bgpd.texi

大名鼎鼎的路由器源码。程序分ZEBRA、OSPFRIP等3个包。程序框架采用一个路由协议一个进程的方式

@deffn Command {show ip bgp community} {}
@deffnx Command {show ip bgp community @var{community}} {}
@deffnx Command {show ip bgp community @var{community} exact-match} {}
@code{show ip bgp community} displays BGP routes which has communities
attribute.  When @var{community} is specified, BGP routes that matches
@var{community} value is displayed.  For this command, @code{internet}
keyword can't be used for @var{community} value.  When
@code{exact-match} is specified, it display only routes that have an
exact match.
@end deffn

@deffn Command {show ip bgp community-list @var{word}} {}
@deffnx Command {show ip bgp community-list @var{word} exact-match} {}
This commands display BGP routes that matches community list
@var{word}.  When @code{exact-match} is specified, display only routes
that have an exact match.
@end deffn

@node Using BGP Communities Attribute,  , Display BGP Routes by Community, BGP Communities Attribute
@comment  node-name,  next,  previous,  up
@subsection Using BGP Communities Attribute

  Following configuration is the most typical usage of BGP communities
attribute.  AS 7675 provides upstream Internet connection to AS 100.
When following configuration exists in AS 7675, AS 100 networks
operator can set local preference in AS 7675 network by setting BGP
communities attribute to the updates.

@example
router bgp 7675
 neighbor 192.168.0.1 remote-as 100
 neighbor 192.168.0.1 route-map RMAP in
!
ip community-list 70 permit 7675:70
ip community-list 70 deny
ip community-list 80 permit 7675:80
ip community-list 80 deny
ip community-list 90 permit 7675:90
ip community-list 90 deny
!
route-map RMAP permit 10
 match community 70
 set local-preference 70
!
route-map RMAP permit 20
 match community 80
 set local-preference 80
!
route-map RMAP permit 30
 match community 90
 set local-preference 90
@end example

  Following configuration announce 10.0.0.0/8 from AS 100 to AS 7675.
The route has communities value 7675:80 so when above configuration
exists in AS 7675, announced route's local preference will be set to
value 80.

@example
router bgp 100
 network 10.0.0.0/8
 neighbor 192.168.0.2 remote-as 7675
 neighbor 192.168.0.2 route-map RMAP out
!
ip prefix-list PLIST permit 10.0.0.0/8
!
route-map RMAP permit 10
 match ip address prefix-list PLIST
 set community 7675:80
@end example

  Following configuration is an example of BGP route filtering using
communities attribute.  This configuration only permit BGP routes
which has BGP communities value 0:80 or 0:90.  Network operator can
put special internal communities value at BGP border router, then
limit the BGP routes announcement into the internal network.

@example
router bgp 7675
 neighbor 192.168.0.1 remote-as 100
 neighbor 192.168.0.1 route-map RMAP in
!
ip community-list 1 permit 0:80 0:90
!
route-map RMAP permit in
 match community 1
@end example

  Following exmaple filter BGP routes which has communities value 1:1.
When there is no match community-list returns deny.  To avoid
filtering all of routes, we need to define permit any at last.

@example
router bgp 7675
 neighbor 192.168.0.1 remote-as 100
 neighbor 192.168.0.1 route-map RMAP in
!
ip community-list standard FILTER deny 1:1
ip community-list standard FILTER permit
!
route-map RMAP permit 10
 match community FILTER
@end example

  Communities value keyword @code{internet} has special meanings in
standard community lists.  In below example @code{internet} act as
match any.  It matches all of BGP routes even if the route does not
have communities attribute at all.  So community list @code{INTERNET}
is same as above example's @code{FILTER}.

@example
ip community-list standard INTERNET deny 1:1
ip community-list standard INTERNET permit internet
@end example

  Following configuration is an example of communities value deletion.
With this configuration communities value 100:1 and 100:2 is removed
from BGP updates.  For communities value deletion, only @code{permit}
community-list is used.  @code{deny} community-list is ignored.

@example
router bgp 7675
 neighbor 192.168.0.1 remote-as 100
 neighbor 192.168.0.1 route-map RMAP in
!
ip community-list standard DEL permit 100:1 100:2
!
route-map RMAP permit 10
 set comm-list DEL delete
@end example

@c -----------------------------------------------------------------------
@node BGP Extended Communities Attribute, Displaying BGP routes, BGP Communities Attribute, BGP
@comment  node-name,  next,  previous,  up
@section BGP Extended Communities Attribute

  BGP extended communities attribute is introduced with MPLS VPN/BGP
technology.  MPLS VPN/BGP expands capability of network infrastructure
to provide VPN functionality.  At the same time it requires a new
framework for policy routing.  With BGP Extended Communities Attribute
we can use Route Target or Site of Origin for implementing network
policy for MPLS VPN/BGP.

  BGP Extended Communities Attribute is similar to BGP Communities
Attribute.  It is an optional transitive attribute.  BGP Extended
Communities Attribute can carry multiple Extended Community value.
Each Extended Community value is eight octet length.

  BGP Extended Communities Attribute provides an extended range
compared with BGP Communities Attribute.  Adding to that there is a
type field in each value to provides community space structure.

  There are two format to define Extended Community value.  One is AS
based format the other is IP address based format.

@table @code
@item AS:VAL
This is a format to define AS based Extended Community value.
@code{AS} part is 2 octets Global Administrator subfield in Extended
Community value.  @code{VAL} part is 4 octets Local Administrator
subfield.  @code{7675:100} represents AS 7675 policy value 100.
@item IP-Address:VAL
This is a format to define IP address based Extended Community value.
@code{IP-Address} part is 4 octets Global Administrator subfield.
@code{VAL} part is 2 octets Local Administrator subfield.
@code{10.0.0.1:100} represents 
@end table

@menu
* BGP Extended Community Lists::  
* BGP Extended Communities in Route Map::  
@end menu

@node BGP Extended Community Lists, BGP Extended Communities in Route Map, BGP Extended Communities Attribute, BGP Extended Communities Attribute
@comment  node-name,  next,  previous,  up
@subsection BGP Extended Community Lists

  Expanded Community Lists is a user defined BGP Expanded Community
Lists.

@deffn Command {ip extcommunity-list standard @var{name} @{permit|deny@} @var{extcommunity}} {}
This command defines a new standard extcommunity-list.
@var{extcommunity} is extended communities value.  The
@var{extcommunity} is compiled into extended community structure.  We
can define multiple extcommunity-list under same name.  In that case
match will happen user defined order.  Once the extcommunity-list
matches to extended communities attribute in BGP updates it return
permit or deny based upon the extcommunity-list definition.  When
there is no matched entry, deny will be returned.  When
@var{extcommunity} is empty it matches to any routes.
@end deffn

@deffn Command {ip extcommunity-list expanded @var{name} @{permit|deny@} @var{line}} {}
This command defines a new expanded extcommunity-list.  @var{line} is
a string expression of extended communities attribute.  @var{line} can
include regular expression to match extended communities attribute in
BGP updates.
@end deffn

@deffn Command {no ip extcommunity-list @var{name}} {}
@deffnx Command {no ip extcommunity-list standard @var{name}} {}
@deffnx Command {no ip extcommunity-list expanded @var{name}} {}
These commands delete extended community lists specified by
@var{name}.  All of extended community lists shares a single name
space.  So extended community lists can be removed simpley specifying
the name.
@end deffn

@deffn {Command} {show ip extcommunity-list} {}
@deffnx {Command} {show ip extcommunity-list @var{name}} {}
This command display current extcommunity-list information.  When
@var{name} is specified the community list's information is shown.

@example
# show ip extcommunity-list 
@end example
@end deffn

@node BGP Extended Communities in Route Map,  , BGP Extended Community Lists, BGP Extended Communities Attribute
@comment  node-name,  next,  previous,  up
@subsection BGP Extended Communities in Route Map

@deffn {Route Map} {match extcommunity @var{word}} {}
@end deffn

@deffn {Route Map} {set extcommunity rt @var{extcommunity}} {}
This command set Route Target value.
@end deffn

@deffn {Route Map} {set extcommunity soo @var{extcommunity}} {}
This command set Site of Origin value.
@end deffn

@c -----------------------------------------------------------------------
@node Displaying BGP routes, Capability Negotiation, BGP Extended Communities Attribute, BGP
@comment  node-name,  next,  previous,  up
@section Displaying BGP Routes

@menu
* Show IP BGP::                 
* More Show IP BGP::            
@end menu

@node Show IP BGP, More Show IP BGP, Displaying BGP routes, Displaying BGP routes
@comment  node-name,  next,  previous,  up
@subsection Show IP BGP

@deffn {Command} {show ip bgp} {}
@deffnx {Command} {show ip bgp @var{A.B.C.D}} {}
@deffnx {Command} {show ip bgp @var{X:X::X:X}} {}
This command displays BGP routes.  When no route is specified it
display all of IPv4 BGP routes.
@end deffn

@example
BGP table version is 0, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 1.1.1.1/32       0.0.0.0                  0         32768 i

Total number of prefixes 1
@end example

@node More Show IP BGP,  , Show IP BGP, Displaying BGP routes
@comment  node-name,  next,  previous,  up
@subsection More Show IP BGP

@deffn {Command} {show ip bgp regexp @var{line}} {}
This command display BGP routes using AS path regular expression (@pxref{Display BGP Routes by AS Path}).
@end deffn

@deffn Command {show ip bgp community @var{community}} {}
@deffnx Command {show ip bgp community @var{community} exact-match} {}
This command display BGP routes using @var{community} (@pxref{Display
BGP Routes by Community}).
@end deffn

@deffn Command {show ip bgp community-list @var{word}} {}
@deffnx Command {show ip bgp community-list @var{word} exact-match} {}
This command display BGP routes using community list (@pxref{Display
BGP Routes by Community}).
@end deffn

@deffn {Command} {show ip bgp summary} {}
@end deffn

@deffn {Command} {show ip bgp neighbor [@var{peer}]} {}
@end deffn

@deffn {Command} {clear ip bgp @var{peer}} {}
Clear peers which have addresses of X.X.X.X
@end deffn

@deffn {Command} {clear ip bgp @var{peer} soft in} {}
Clear peer using soft reconfiguration.
@end deffn

@deffn {Command} {show debug} {}
@end deffn

@deffn {Command} {debug event} {}
@end deffn

@deffn {Command} {debug update} {}
@end deffn

@deffn {Command} {debug keepalive} {}
@end deffn

@deffn {Command} {no debug event} {}
@end deffn

@deffn {Command} {no debug update} {}
@end deffn

@deffn {Command} {no debug keepalive} {}
@end deffn

@node Capability Negotiation, Route Reflector, Displaying BGP routes, BGP
@comment  node-name,  next,  previous,  up