Dell Force10 C150 Configuration Manual page 244

Step Command Syntax
{ deny | permit }
2
parameter
exit
3
router bgp
4
neighbor
5
peer-group-name
filter-list
out
| }
Regular Expressions as filters
Regular expressions are used to filter AS paths or community lists. A regular expression is a special
character used to define a pattern that is then compared with an input string.
For an AS-path access list as shown in the commands above, if the AS path matches the regular expression
in the access list, then the route matches the access list.
Figure 10-27
regular expression to deny routes originating in AS 32.
244 | Border Gateway Protocol IPv4 (BGPv4)
Command Mode
filter CONFIG-AS-PATH
AS-PATH ACL
CONFIGURATION
as-number
{ | CONFIG-ROUTER-B
ip-address
GP
}
in
{
as-path-name
applies access list Eagle to routes inbound from BGP peer 10.5.5.2. Access list Eagle uses a
Purpose
Enter the parameter to match BGP AS-PATH for
filtering. This is the filter that will be used to match the
AS-path. The entries can be any format, letters,
numbers, or regular expressions.
This command can be entered multiple times if multiple
filters are desired.
See Table 10-4 for accepted expressions.
Return to CONFIGURATION mode
Enter ROUTER BGP mode.
Use a configured AS-PATH ACL for route filtering and
manipulation.
If you assign an non-existent or empty AS-PATH ACL,
the software allows all routes.