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

Ondrej Zajicek santiago at
Wed Mar 2 20:16:11 CET 2011

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 +;

would help. The first line (which is probably undocumented syntax) will
reset bgp_path, so you could prepend PREP_ASN and than prepend

Elen sila lumenn' omentielvo

Ondrej 'SanTiago' Zajicek (email: santiago at
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3,
"To err is human -- to blame it on a computer is even more so."
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