Well, I would argue that your original solution was still correct, as
technically speaking, that route DID pass through AS39 at some point
of its origination in it ;-)

Neat solution, though!

--
Marko Milivojevic - CCIE #18427
Senior Technical Instructor - IPexpert

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On Wed, Nov 3, 2010 at 15:41, J D'Silva <[email protected]> wrote:
> Yes, I suppose that would match anything originating from AS39 as well.
> Let's try this instead then:
>
> _39_.*
>
> So now there must be at least one other AS before AS39 for the rexex to
> filter.
>
> :)
>
>
>
> On Wed, Nov 3, 2010 at 4:42 AM, Jason Maynard <[email protected]>
> wrote:
>>
>> That is correct
>>
>>
>>
>>
>>
>> The list was added for a couple of reasons
>>
>> ·         make some over analyze the requirements
>>
>> ·         perhaps create some confusion
>>
>> ·         add complex scenarios in the future
>>
>>
>>
>>
>>
>> If the list was not provided would this be correct?
>>
>>
>>
>> Create a regular expression that filters routes that pass through AS39
>>
>> _39_
>>
>>
>>
>> Could this also match anything that has originated in AS39?
>>
>>
>>
>>
>>
>> Thanks Jason!
>>
>>
>>
>> From: [email protected]
>> [mailto:[email protected]] On Behalf Of J D'Silva
>> Sent: November-02-10 10:10 PM
>>
>> To: OSL Routing and Switching
>> Subject: Re: [OSL | CCIE_RS] Question 161
>>
>>
>>
>> Hi Jason et al,
>>
>> First time sending to the list.  I just recently entered into the IPexpert
>> world and joined this list sometime last week.  I look forward to
>> participating in the conversations.
>>
>> For the regex question at hand, am mistaken in thinking that the provided
>> list of AS paths is actually irrelevant to the question?  What I'm filtering
>> for I'm going to filter for regardless of what AS_PATH happens to come my
>> way?
>>
>> At any rate, here's my regexs:
>>
>> Create a regular expression that filters routes that originate in AS321
>>
>> _321$
>>
>> Create a regular expression that filters routes that have instances of
>> AS200 in the path
>>
>> _200_
>>
>> Create a regular expression that filters routes that are learned from AS10
>>
>> ^10_
>>
>> Create a regular expression that filters routes that are locally
>> originated
>>
>> ^$
>>
>> Create a regular expression that filters all routes from any AS
>>
>> .*
>>
>> Create a regular expression that filters routes that pass through AS39
>>
>> _39_
>>
>> Create a regular expression that filters routes that have a number "20"
>> anywhere within the AS number or path
>>
>> 20
>>
>> Regards,
>>
>> Jason D'Silva
>>
>>
>> On Tue, Nov 2, 2010 at 6:24 PM, Jason Maynard <[email protected]>
>> wrote:
>>
>> Wondering if everyone had a chance at the questions below before I post
>> the answers
>>
>>
>>
>> If no one responds I will post them tomorrow.
>>
>>
>>
>>
>>
>> From: [email protected]
>> [mailto:[email protected]] On Behalf Of Jason Maynard
>> Sent: October-30-10 3:10 PM
>> To: 'OSL Routing and Switching'
>> Subject: [OSL | CCIE_RS] Question 161
>>
>>
>>
>> Alot of people seem to struggle with BGP regular expressions so I put them
>> together the following questions
>>
>> Here are a list of AS paths  (I just threw them together so we can create
>> regular expressions). The AS that you are in is AS1.
>>
>> 100 110 2009 20093 20100 54 321
>> 100 110 2009 20111 129 22 10
>> 10 200 19 24 39 4 32
>> 16 100 888 1339 2
>>
>> Create a regular expression that filters routes that originate in AS321
>> Create a regular expression that filters routes that have instances of
>> AS200 in the path
>> Create a regular expression that filters routes that are learned from AS10
>> Create a regular expression that filters routes that are locally
>> originated
>> Create a regular expression that filters all routes from any AS
>> Create a regular expression that filters routes that pass through AS39
>> Create a regular expression that filters routes that have a number "20"
>> anywhere within the AS number or path
>>
>> Regular Expressions and their 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
>>
>>
>> Have fun
>>
>> _______________________________________________
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>> visit www.ipexpert.com
>>
>>
>
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>
>
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