deny (bgp-as-path-list)
Creates and configures a deny as-path-list rule. The deny rule specifies
a regular expression to match. This regular expression, is matched against the BGP AS paths
contained in routing updates. AS paths matching the provided string are filtered and a deny
action is applied.
Supported in the following platforms:
- Service Platforms — NX9500, NX9600
Syntax
deny as-path <REG-EXP>
Parameters
deny as-path <REG-EXP>
| deny as-path <REG-EXP> |
Configures a match criteria (regular expression).
- <REG-EXP> – Specify the regular expression to match (should not exceed 64
characters and should be unique to the AS path list rule)
Regular expressions are treated as a ‘ASCII string‘ and not as a sequence of
numbers. Create a regular expression ideally suited to filter the required AS
paths.
|
Usage Guidelines
The following table lists some of the characters used in forming regular expressions:
Table 1.
| Character to use |
Description |
| ^ |
Indicates the start of a string |
| $ |
Indicates the end of a string |
| _ (underscore) |
Indicates a comma, left brace, right brace, start and end of an input string,
or a space. For example, “_ _”. |
Examples
nx9500-6C8809(config-bgp-as-path-list-test)#deny as-path ^100$
nx9500-6C8809(config-bgp-as-path-list-test)#show context
bgp as-path-list test
deny as-path ^100$
nx9500-6C8809(config-bgp-as-path-list-test)#
