Been hearing about the command «show ip bgp regexp» but never really put it to use at work. I think its time I use this command to filter out learned bgp routes. I got these tables from the Internetwork Expert Blog I like to read. Time to put this into good use by beginning to use the basics first before proceeding to much advance filtering.
+------------------------------------------------------+ | CHAR | USAGE | +------------------------------------------------------| | ^ | Start of string | |------|-----------------------------------------------| | $ | End of string | |------|-----------------------------------------------| | [] | Range of characters | |------|-----------------------------------------------| | - | Used to specify range ( i.e. [0-9] ) | |------|-----------------------------------------------| | ( ) | Logical grouping | |------|-----------------------------------------------| | . | Any single character | |------|-----------------------------------------------| | * | Zero or more instances | |------|-----------------------------------------------| | + | One or more instance | |------|-----------------------------------------------| | ? | Zero or one instance | |------|-----------------------------------------------| | _ | Comma, open or close brace, open or close | | | parentheses, start or end of string, or space | +------------------------------------------------------+
+-------------+---------------------------+ | Expression | Meaning | |-------------+---------------------------| | .* | Anything | |-------------+---------------------------| | ^$ | Locally originated routes | |-------------+---------------------------| | ^100_ | Learned from AS 100 | |-------------+---------------------------| | _100$ | Originated in AS 100 | |-------------+---------------------------| | _100_ | Any instance of AS 100 | |-------------+---------------------------| | ^[0-9]+$ | Directly connected ASes | +-------------+---------------------------+ © http://ciscodreamer.blogspot.com/2009/04/bgp-regular-expressions.html
