Riverstone Networks WICT1-12 - Manual (Page 262)

16-4 Riverstone Networks RS Switch Router User Guide Release 8.0
Basic BGP Tasks BGP Configuration Guide
16.2.4 Adding a BGP Peer
To add BGP peers to BGP peer groups, enter the following command in Configure mode.
You can specify either a peer group identifier or a peer host IP address when creating an export destination for BGP
routes (with the
ip-router policy create bgp-export-destination
command), a source for exporting BGP
routes into other protocols (with the
ip-router policy create bgp-export-source
command), or a source
for importing BGP routes (with the
ip-router policy create bgp-import-source
command).
16.2.5 Starting BGP
BGP is disabled by default. To start BGP, enter the following command in Configure mode.
16.2.6 Using AS-Path Regular Expressions
AS path regular expressions are used as one of the parameters for determining which routes are accepted and which
routes are advertised. An AS path regular expression is a regular expression where the alphabet is the set of AS
numbers from 1 through 65535.
The following wildcards and operators can be used to build a regular expression:
“ “ (quotation marks) Encloses an AS path regular expression
() (parentheses) Used to group expressions within the AS path regular expression
. (period) Matches any AS number
* (asterisk Matches zero or more repetitions of the preceding expression
+ (plus sign) Matches one or more repetitions of the preceding expression
? (question mark) Matches zero or one repetition of the prceding expression
(space) And
| (vertical line) Or
A set of AS numbers is delimited by the [] (square bracket) symbols. The set can be a list of AS numbers separated by
a space or a range of AS numbers separated by a - (dash). A ^ (circumflex) prepended to a list of AS numbers means
that valid members are those AS numbers that are not in the list. Note that a null or empty string is not an instance in
the alphabet, therefore the set [^700] does not match an empty string.
Add a host to a BGP peer group.
bgp add peer-host
<ipaddr>
group
<number-or-string>
Start BGP.
bgp start