[j-nsp] Policy Statement Question

[Michael Loftis]

--On January 28, 2006 1:25:25 PM -0500 Chris Davies <isp at daviesinc.com> 
wrote:

> I have two current issues which might have one solution.  Our initial
> testing shows that the Juniper reduced average latency about 10ms, so,
> even though our Cisco wasn't showing any real signs of cpu usage, it
> appears (and feels like) the Juniper has made an improvement in
> performance which was a small surprise.
>
> The issue I'm working with now is that we buy transit from two
> providers, a Tier 1 (Cogent) and a Tier 2 (Internap) if you wanted to
> use 'old' terms.  The problem I am running into is that since Internap
> is technically a Tier 2 (they buy transit from Tier 1 providers), only
> 25k of the 175k routes have shorter ASPaths to the destination.
>
> Since Internap is only adding 1 router hop and 1 AS Hop, I should ASPad
> on Cogent's side.  That would perhaps level the playing field for
> inbound traffic.
>
> If I understand this right, can someone do a sanity check?  (The
> IOS2junos convertor really made things a mess for me, so, I tried to
> figure out what it needed and stripped out the rest of it)
>
> policy-statement aspad_Cogent {
>      term aspad_Cogent {
>          then as-path-prepend 11110;
>      }
> }
>
> Do I need a from condition if I want to unconditionally aspad?

Uhm, no but i do think you need a then next policy to use it in the example 
you give below, else bgp_distributes won't be hit...I think.  I could be 
wrong and my memory is fuzzy, but that seems right since that's how I'm 
handling multiple policy bits on our M7i.

>
> If I understand it, I do not want an accept here since I want the next
> policy statement to also be executed.
>
> Now, on my A-Peer with Cogent (they use multihop), I would set
>
> export [ aspad_Cogent bgp_distributes ]
>
> At that point, I need to
>
> clear bgp neighbor (a-peer's ip) soft
>
> to send the config.

Eh, I don't think you need to clear the BGP session at all in JunOS, during 
the next scans it will adjust the FIB and RIB.

>
> AS Padding on my exports should result in inbound traffic perhaps
> choosing a better path since the ASPath's across Cogent and Internap
> would be a little more balanced.  When I add another provider alongside
> these two, if it is another Tier 1 provider, I would probably need to
> pad their incoming as well.
>
> If someone could give this a quick sanity check, I'd appreciate it.  12
> years of IOS -> Junos has been a bit of a challenge.  :)
>
> Thanks.
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