[j-nsp] bgp graceful-shutdown receiver

[Mark Tinka]

On 4/18/22 17:24, Michael Hare via juniper-nsp wrote:
> Hello,
>
> Is anyone using "bgp graceful-shutdown receiver" successfully out-of-the-box for eBGP peers without modifying their import policies to account for 65535:0?
>
> For example our production AS peers with lab AS over eBGP.  Import policy on the production side sets local preference.  "I was assuming" that the reception of 65535:0 would set localpref to 0 and that's not what I see.  JTAC is claiming this is expected and that any import policy that sets local preference will override having graceful-shutdown receiver enabled.
>
> Yes, I have confirmed gshut is enabled and I am indeed receiving 65535:0.   If I change my import policy to match 65535:0 and set local pref to 0, it unsurprisingly works.  Thankfully I have disaggregated the terms that accept a route from those that set local preference so I'm just looking at a major annoyance instead of major pain, but I find this a bit unbelievable as a default behavior.  But perhaps I'm missing the concept of why the hook to set localpref appears to be at start of policy evaluation and not after route acceptance inside RPD.

My understanding is that 65535:0 is "universally" accepted across eBGP 
neighbors to signal LOCAL_PREF=0. However, receiving operators need to 
setup the policy infrastructure to make that happen.

I'd find it rather odd if a vendor automatically changed the LOCAL_PREF 
to 0 for a route that shipped with 65535:0, without the operator 
specifically pre-defining the policy infrastructure to support that. I 
certainly wouldn't want that from my vendor.

Unless I am missing something...

Mark.