Comments on: How do I stop a confederation from being used as transit? http://blog.internetworkexpert.com/2007/12/26/q-how-do-i-stop-a-confederation-from-being-used-as-transit/ Helping you become a Cisco Certified Internetwork Expert Fri, 05 Sep 2008 15:08:14 +0000 http://wordpress.org/?v=2.5.1 By: Alexandre Ribeiro http://blog.internetworkexpert.com/2007/12/26/q-how-do-i-stop-a-confederation-from-being-used-as-transit/#comment-359 Alexandre Ribeiro Sun, 17 Feb 2008 06:13:17 +0000 http://blog.internetworkexpert.com/?p=8#comment-359 Brian, Instead of refering to ? as a true/false operator, you could you Cisco's explanation, which I think is a bit more enlightning: "? - Matches zero or one occurrence of the pattern. (Precede the question mark with Ctrl-V sequence to prevent it from being interpreted as a help command.) " P.S.- Great blog! " Brian,

Instead of refering to ? as a true/false operator, you could you Cisco’s explanation, which I think is a bit more enlightning:

“? - Matches zero or one occurrence of the pattern. (Precede the question mark with Ctrl-V sequence to prevent it from being interpreted as a help command.) ”

P.S.- Great blog!
“

]]> By: Brian McGahan, CCIE 8593 http://blog.internetworkexpert.com/2007/12/26/q-how-do-i-stop-a-confederation-from-being-used-as-transit/#comment-220 Brian McGahan, CCIE 8593 Wed, 06 Feb 2008 17:35:35 +0000 http://blog.internetworkexpert.com/?p=8#comment-220 You can do that too. For clarity you may want to use extra parens to show what the or actually switches between. I.e.: (^$)|(^\(.*\)$) You can do that too. For clarity you may want to use extra parens to show what the or actually switches between. I.e.:

(^$)|(^\(.*\)$)

]]> By: Em http://blog.internetworkexpert.com/2007/12/26/q-how-do-i-stop-a-confederation-from-being-used-as-transit/#comment-180 Em Sun, 03 Feb 2008 07:16:28 +0000 http://blog.internetworkexpert.com/?p=8#comment-180 ok! here it goes: show ip bgp regexp ^$|^\(.*\)$ match empty set OR match beginning/ending with parenthesis ok! here it goes:

show ip bgp regexp ^$|^\(.*\)$

match empty set OR
match beginning/ending with parenthesis

]]> By: Em http://blog.internetworkexpert.com/2007/12/26/q-how-do-i-stop-a-confederation-from-being-used-as-transit/#comment-178 Em Sun, 03 Feb 2008 07:07:14 +0000 http://blog.internetworkexpert.com/?p=8#comment-178 i got this to work: R2#show ip bgp regexp ^\(.*\)$ this means we only want to match routes where the AS path starts and ends with a parenthesis, which is what routes starting in our confed would look like. I used '*' instead of '+' because '+' was not matching the 'A' prefix connected to R2. not sure if that would work in all cases though...trying to think of what else the AS paths could look like... anyways, nice post. bgp regexp is fun :) i got this to work:

R2#show ip bgp regexp ^\(.*\)$

this means we only want to match routes where the AS path starts and ends with a parenthesis, which is what routes starting in our confed would look like. I used ‘*’ instead of ‘+’ because ‘+’ was not matching the ‘A’ prefix connected to R2.

not sure if that would work in all cases though…trying to think of what else the AS paths could look like…

anyways, nice post. bgp regexp is fun :)

]]> By: Em http://blog.internetworkexpert.com/2007/12/26/q-how-do-i-stop-a-confederation-from-being-used-as-transit/#comment-177 Em Sun, 03 Feb 2008 06:36:50 +0000 http://blog.internetworkexpert.com/?p=8#comment-177 very cool. How do you get the IOS to take the question mark without trying to do help? very cool. How do you get the IOS to take the question mark without trying to do help?

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