Description

The configured MED/metric route attribute is not inherited to originated Type-5 route

Symptoms

The customer reported that the configured MED/metric route attribute is not inherited to the originated Type-5 route, Also they tried to change the route attribute by setting local preference via export policy under ip-prefix-routes

 

labroot@R1-re0> show configuration routing-instances VRF-T5-IRB12-13 routing-options                 

static {

   route 10.10.10.0/24 {

        discard;

       metric 50;

       tag 5000;

       community 64999:111;

       as-path {

           path 64999;

       }

   }

}

 

labroot@R1-re0> show route advertising-protocol bgp 4.4.4.4 table VRF-T5-IRB12-13 10.10.10.0/24 detail                       

 

VRF-T5-IRB12-13.inet.0: 4 destinations, 7 routes (4 active, 0 holddown, 0 hidden)

* 10.10.10.0/24 (2 entries, 1 announced)

BGP group EVPN type Internal

    Route Distinguisher: 2.2.2.2:9

    VPN Label: 26

     Nexthop: Self

    Flags: Nexthop Change

    MED: 50

     Localpref: 100

    AS path: [65000] 64999 I 

     Communities: 64999:111 target:64999:1213

 

labroot@jtac-mx2008dc-proto-r2001-re0> show route advertising-protocol bgp 4.4.4.4 table VRF-T5-IRB12-13.evpn.0 match-prefix *10.10.10.0* detail    

 

VRF-T5-IRB12-13.evpn.0: 4 destinations, 4 routes (4 active, 0 holddown, 0 hidden)

* 5:2.2.2.2:9::0::10.10.10.0::24/248 (1 entry, 1 announced)

BGP group EVPN type Internal

    Route Distinguisher: 2.2.2.2:9

    Route Label: 26

    Overlay gateway address: 0.0.0.0

     Nexthop: Self

    Flags: Nexthop Change

     Localpref: 100

    AS path: [65000] 64999 I 

     Communities: 64999:111 target:64999:1213

 

Solution

The EVPN Type-5 behavior of inheriting route attributes, it only inherit the as-path, community, and local preference attributes from the originator IPv4/IPv6 route, and the metric/MED is not supported as of now.

 

For export policy under ip-prefix-route it either accepts or rejects IPv4/IPv6 prefixes for which we want to generate Type-5 routes, it does not modify route attributes.

However, in the latest releases, we can use the export policy to modify/set community values while generating Type-5 EVPN routes. 

 

Modification History

2024-03-10 : Article Created

Related Information

https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/route-attributes.html
https://www.juniper.net/documentation/us/en/software/junos/evpn-vxlan/Other/ip-prefix-routes-edit-routing-instances-protocols-evpn.html