[c-nsp] BGP Regex to allow ISP customers

[Dragan Jovicic]

That should be

^(100_)+([0-9]+)(_\2)*$

But the above should* work as well...

On Tue, Oct 18, 2016 at 3:31 AM, Dragan Jovicic <draganj84 at gmail.com> wrote:

> It's been a while but, the following might do it
>
> ^(100_)+([0-9_]+)(_\2)*$
>
> It matches any customer of 100 also accounting for case where both 100 and
> customer are prepending.
>
>
> On Tue, Oct 18, 2016 at 2:28 AM, Randy via cisco-nsp <
> cisco-nsp at puck.nether.net> wrote:
>
>> _______________________________________________
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>> https://puck.nether.net/mailman/listinfo/cisco-nsp
>> archive at http://puck.nether.net/pipermail/cisco-nsp/
>>
>>
>> ---------- Forwarded message ----------
>> From: Randy <randy_94108 at yahoo.com>
>> To: Nick Cutting <ncutting at edgetg.com>, Brandon Ewing <
>> nicotine at warningg.com>, "cisco-nsp (cisco-nsp at puck.nether.net)" <
>> cisco-nsp at puck.nether.net>
>> Cc:
>> Date: Tue, 18 Oct 2016 00:24:23 +0000 (UTC)
>> Subject: Re: [c-nsp] BGP Regex to allow ISP customers
>>
>> ----- Original Message -----
>> From: Nick Cutting <ncutting at edgetg.com>
>> To: Brandon Ewing <nicotine at warningg.com>; "cisco-nsp (
>> cisco-nsp at puck.nether.net)" <cisco-nsp at puck.nether.net>
>> Sent: Monday, October 17, 2016 4:32 PM
>> Subject: Re: [c-nsp] BGP Regex to allow ISP customers
>>
>> Thank you for your answer.
>>
>> The problem is I do not know the ASN's of the ISP's customers.
>> Robert - I am afraid that this particular ISP does not have a community
>> for this, nor can they send me just their customer routes.
>>
>> From: Brandon Ewing [mailto:nicotine at warningg.com]
>> Sent: Monday, October 17, 2016 5:45 PM
>> To: cisco-nsp (cisco-nsp at puck.nether.net) <cisco-nsp at puck.nether.net>
>> Cc: Nick Cutting <ncutting at edgetg.com>
>> Subject: Re: [c-nsp] BGP Regex to allow ISP customers
>>
>>
>> The original message is attached because it is signed.
>>
>>
>> Hi,
>> Perhaps something like this:
>>
>> ip as-path access-list 100 permit ^100_[0-9]*$
>> ip as-path access-list 100 permit ^100_([0-9]+)_\1_\1$
>>
>> first line would match as100 only and as100 and it's customers while the
>> second would allow three prepends from customers of as100. I am sure there
>> is a better way to do this though...
>>
>>
>> ./Randy
>> ________________________________
>>
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>>
>>
>