Newbie question - create filter for prefixes to export and also modify bgp next hop

[Mathias Wolkert]

Hi

On 3/2/11 20:16 , Ondrej Zajicek wrote:
> On Wed, Mar 02, 2011 at 04:15:48PM +0100, Mathias Wolkert wrote:
>>>> Another thing.
>>>>
>>>> One of these prefixes I want to originate from a different AS.
>>>> In IOS and quagga I can do this with "set as-path prepend" and get:
>>>>
>>>> prefix/mask<local_as>   <prepended_as>   i
>>>>
>>>
>>> Are you sure? This looks wrong to me.
>>>
>>>> Doing this in BIRD gives me a different behavior and I get:
>>>>
>>>> prefix/mask<prepended_as>   <local_as>   i
>>>>
>>>> A little bird told me about this not beeing wrong, but closer to what
>>>> the standard states.
>>>>
>>>> Do you agree?
>>>> How would I get around this, another table and pipes?
>>>
>>> So you would like to change originator? Which way? YOU would like to
>>> be an originator?
>>
>> Yes, I'd like to change the originator to "prepended_as" and also have
>> "local_as" in the path like I have on quagga/IOS.
>
> Probably something like this:
>
> bgp_path = + empty +;
> bgp_path.prepend(PREP_ASN);
> bgp_path.prepend(LOCAL_ASN);
>
> would help. The first line (which is probably undocumented syntax) will
> reset bgp_path, so you could prepend PREP_ASN and than prepend
> LOCAL_ASN.
>

That worked out fine.
Thanks a lot!

/Tias