[c-nsp] question with adj-rib-out and policy engine order and show commands

[Aaron Gould]

Question with adj-rib-out and policy engines.  I've look at bassam halabi's
explanation in inet routing archs, googles, etc, etc.

 

Is "show ip bpg neighbor 1.2.3.2 advertised-routes" PRE-outbound-policy or
POST-outbound-policy?

 

someone please explain why I see r1 "show ip bpg neighbor 1.2.3.2
advertised-routes" showing metric 2, but I see on r2 that it rcv's it change
as planned to metric 17.

 

My question is really just about why I see metric 2 on advertise-route route
of r1, when I know it's getting set to metric 17.  Why don't I see what the
policy is changing it to on the sending router, r1 ?

 

I tried to only include pertinent info to keep this short and to the point.

 

*** R1..... Sending an advertisement..

 

r1#sh ip bgp neighbors 1.2.3.2 advertised-routes | be Network

   Network          Next Hop            Metric LocPrf Weight Path

*> 10.0.2.1/32      10.0.1.1                 2         32768 ?

 

r1#sh run | sec router bgp

router bgp 123

...

neighbor 1.2.3.2 route-map my-routemap-xmit out

 

route-map my-routemap-xmit, permit, sequence 10

    ip address prefix-lists: my-prefixlist-out

  Set clauses:

    metric 17

 

r1#sh ip prefix-list

   seq 1 permit 10.0.2.1/32

 

*** R2... Receiving that advertisement correctly as altered Metric 17

 

r2#sh ip bgp neighbors 1.2.3.1 routes | be Network

   Network          Next Hop            Metric LocPrf Weight Path

*> 10.0.2.1/32      1.2.3.1                 17             0 123 ?

 

Total number of prefixes 1

r2#

r2#sh ip ro bgp

     10.0.0.0/32 is subnetted, 1 subnets

B       10.0.2.1 [20/17] via 1.2.3.1, 09:40:38

 

-Aaron