[j-nsp] inject unresolvable static route via bgp

Alexander Dube nsp at layerwerks.net
Thu Jun 22 09:16:03 EDT 2017

Hi Alex, 

yes, is resolvable on the core router. 

Your hint with advertising the connected routes to the injection router, works like a charm and is a suitable solution for us. Thank you :) 

Best regards 

Von: "Alexander Arseniev" <arseniev at btinternet.com> 
An: "Alexander Dube" <nsp at layerwerks.net>, "juniper-nsp" <juniper-nsp at puck.nether.net> 
Gesendet: Donnerstag, 22. Juni 2017 14:27:12 
Betreff: Re: [j-nsp] inject unresolvable static route via bgp 


Is resolvable on a core router then? 

Via in interface/connected subnet perhaps? 

If yes then announce all conected subnets from core router(s) via iBGP to Your VMX. 

Then configure Your statics on VMX with "resolve" knob, and announce them via iBGP back to core router(s). Your VMX will keep the original "protocol NH" as specified in VMX config. 



On 22/06/2017 12:39, Alexander Dube wrote: 


we try to implement a route injection with a vmx to reduce the count of static routes on our core routers ( a very large amount ... ) 

I've the problem, that if i set a static route on the vmx, it will be advertised with the wrong next-hop ( self in this case ) 
The session between the vmx and our core router is ibgp currently. Even with multihop no-nexthop-change it isnt working 

For example: 

show routing-options static route 

This will result in: 

show route detail 

inet.0: 18 destinations, 18 routes (18 active, 0 holddown, 0 hidden) (1 entry, 1 announced) 
*Static Preference: 5 
Next hop type: Reject, Next hop index: 0 
Address: 0xa06fec4 
Next-hop reference count: 2 
State: <Active Int Ext> 
Local AS: 123 
Age: 2:06 
Validation State: unverified 
Task: RT 
Announcement bits (3): 0-KRT 4-BGP_RT_Background 5-Resolve tree 4 
AS path: I 

show route advertising-protocol bgp 

inet.0: 18 destinations, 18 routes (18 active, 0 holddown, 0 hidden) 
Prefix Nexthop MED Lclpref AS path 
* Self 100 I 

Is there any way that the router is advertising the correct unmodified next-hop and not self? 
I know that that this is possible with modifying the next-hop via the export policy and this works very well, but in our specific case this would result into a more than 500k lines policy-statement... 

Kind regards 

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