Configuring Inbound Route Filters for IPv4 BGP in Gaia Clish

Accepts all IPv4 routes that match this filter, except those route that are explicitly restricted by a more specific rule Set of traffic parameters and other conditions in a Rule Base (Security Policy) that cause specified actions to be taken for a communication session..

Accepting routes is the default behavior, unless the "restrict" option is configured.

Configures a new policy to import BGP routes from a particular peer Autonomous System.

A valid AS_PATH regular expression contains only digits and these special characters:

• . - The period character matches any single character.

• \ - The backslash character matches the character right after the backslash. For pattern recall, match the pattern indicated by the digit following the backslash. To enter the backslash character, enter two backslash characters \\ (the first backslash character escapes the second backslash character).

• ^ - The circumflex character matches the characters or null string at the beginning of the AS path.

• $ - The dollar character matches the characters or null string at the end of the AS path.

• ? - The question mark matches zero or one occurrence of the pattern before "?". To enter the question mark, press the CTRL V keys and then press the Shift ? keys.

• * - The asterisk character matches zero or more occurrences of the pattern before "*".

• + - The plus character matches one or more occurrences of the pattern before "+".

• | - The pipeline (vertical line) character matches one of the patterns on either side of the "|" character.

• _ - The underscore character matches comma (,), left brace ({), right brace (}), beginning of ASPath (^), end of ASPath ($), or a whitespace (space or tabulation).

• [ ] - The square brackets match the set of characters or range of characters separated by a hyphen (-) within the brackets.

• ( ) - The round brackets group one or more patterns into a single pattern.

• {m n} - Matches at least "m" and at most "n" repetitions of the pattern before "{m,n}". Both "m" and "n" are positive integers, and "m" is less than or equal to "n".

• {m} - Matches exactly "m" repetitions of the pattern before "{m}". The "m" is a positive integer.

• {m,} - Matches "m" or more repetitions of the pattern before "{m}". The "m" is a positive integer.

To generate an empty regular expression, use "empty".

Matches routes containing a given Community in the BGP Community attribute.

Each Community is identified by a Community ID and an Autonomous System number.

• off - Removes this Community filter from this BGP import policy

• on - Adds this Community match filter to this BGP import policy

Assigns a BGP weight to all routes that match this filter, except those that match a more specific filter with a different weight value configured.

BGP stores any routes that are rejected by not mentioning them in a route filter.

BGP explicitly mentions these rejected routes in the routing table and assigns them a "restrict" keyword with a negative weight.

A negative weight prevents a route from becoming active, which means that it is not installed in the forwarding table or exported to other protocols.

This feature eliminates the need to break and re-establish a session upon reconfiguration if import policy is changed.

Range: 0-65535

Default: No weight

Rejects all IPv4 routes that match this filter, except those that match a more specific filter that is set to "accept".

Configures import policy for a specific network.

Range: For IPv4 - Dotted-quad ([0-255].[0-255].[0-255].[0-255]) / [0-32]

Range: For IPv6 - Dotted-octet ([0-F]:[0-F]:[0-F]:[0-F]:[0-F]:[0-F]:[0-F]:[0-F]) / [0-128]

Default: None

There are different mechanisms, by which routes can be matched against the configured subnet. A match type must be configured following the subnet.

Accepts any route with prefix equal to the specified network, whose mask length falls within a particular range.

There are different mechanisms, by which routes can be matched against the configured subnet. A match type must be configured following the subnet.

Accepts only routes with prefix and mask length exactly equal to the specified network.

Assigns a BGP local preference to all routes that match this filter, except those that match a more specific filter with a different local preference value configured.

The local preference value is sent automatically when redistributing external BGP routes to an internal BGP route.

The local preference parameter is ignored if used on internal BGP import statements.

greater values are preferred by the routing system when it selects between competing BGP routes.

Range: 0-4294967295

Default: No local preference

There are different mechanisms, by which routes can be matched against the configured subnet. A match type must be configured following the subnet.

Rejects all routes that match this policy rule, except those that match a more specific filter that is set to "accept".

There are different mechanisms, by which routes can be matched against the configured subnet. A match type must be configured following the subnet.

Matches routes contained within the specified network, but only more specific (for example, with a greater mask length).