“metric” is not something communicated via the BGP protocol.  

  I think you want to research LOCAL_PREF.  You could map the local metric, 
into BGP LOCAL_PREF values, and send that to BPG peers.  Depending on what you 
are doing, MED, may also be a possible solution.

  But what you are seeing, which is the first learned route is the route uses, 
is typical BGP behaviour when multiple equal BGP routes are received

 

Tom

  

 

> On Aug 16, 2016, at 10:00 AM, Templin, Fred L <[email protected]> 
> wrote:
> 
> Hello,
>  
> I have three BGP routers on a shared IPv6 link and using link-local only 
> addressing.
> Router A (fe80::1) peers with Routers B (fe80::2) and C (fe80::3), but B and 
> C do not
> peer with each other. Router A receives prefix advertisements from B and C, 
> but
> does not distribute prefixes learned from B to C and vice-versa (it 
> black-holes them).
>  
> Router B advertises the prefix 2001:db8:5::/64 with metric 1024 to router A. 
> At a
> later time, Router C then advertises the same prefix with metric 1 to router 
> A.
> However, router A continues to consider B as the best next hop for the prefix
> even though the metric advertised by router C was lower.
>  
> It seems to be due to the fact that router B advertised the prefix first, but 
> I want
> router A to prefer router C based on the lower metric as a higher precedence 
> than
> age. Is there a way to configure quagga to use metric as the higher precedence
> for best path selection?
>  
> See below for the BGP table information for router A:
>  
> Thanks – Fred
> [email protected] <mailto:[email protected]>
>  
>  
> n8# sh ipv6 bgp
> BGP table version is 0, local router ID is 10.0.4.2
> Status codes: s suppressed, d damped, h history, * valid, > best, i - 
> internal,
>               r RIB-failure, S Stale, R Removed
> Origin codes: i - IGP, e - EGP, ? - incomplete
>  
>    Network          Next Hop            Metric LocPrf Weight Path
> *> 2001:db8:1::/64  fe80::2               1024             0 2 ?
> *> 2001:db8:2::/64  fe80::3               1024             0 3 ?
> *  2001:db8:5::/64  fe80::3                  1             0 3 ?
> *>                  fe80::2               1024             0 2 ?
>  
> Total number of prefixes 3
> n8#
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